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Douliu, Taiwan

Shih M.-H.,Johns Hopkins University | Kao S.-C.,Johns Hopkins University | Kao S.-C.,Lin Kou Medical Center | Wang W.,Johns Hopkins University | And 2 more authors.
Journal of Pain | Year: 2012

Mammalian target of rapamycin (mTOR) controls mRNA translation and is critical for neuronal plasticity. However, how it participates in central sensitization underlying chronic pain is unclear. Here, we show that NMDA receptors are required for the functional role of spinal cord mTOR in bone cancer pain induced by injecting prostate cancer cells (PCCs) into the tibia. Intrathecal rapamycin, a specific mTOR inhibitor, dose dependently attenuated the development and maintenance of PCC-induced mechanical allodynia and thermal hyperalgesia. Rapamycin alone did not affect locomotor activity and acute responses to thermal or mechanical stimuli. Phosphorylation of mTOR and p70S6K (a downstream effector) was increased time dependently in L4-5 dorsal horn and transiently in L4-5 dorsal root ganglions on the ipsilateral side after PCC injection, although total expression of mTOR or p70S6K was not changed in these regions. The increases in dorsal horn were abolished by intrathecal infusion of DL-AP5, an NMDA receptor antagonist. Moreover, NMDA receptor subunit NR1 colocalized with mTOR and p70S6K in dorsal horn neurons. These findings suggest that PCC-induced dorsal horn activation of the mTOR pathway participates in NMDA receptor-triggered dorsal central sensitization under cancer pain conditions. Perspective: The present study shows that inhibition of spinal mTOR blocks cancer-related pain without affecting acute pain and locomotor function. Given that mTOR inhibitors are FDA-approved drugs, mTOR in spinal cord may represent a potential new target for preventing and/or treating cancer-related pain. © 2012 by the American Pain Society. Source

Kopach O.,Bogomoletz Institute of Physiology | Kao S.-C.,Johns Hopkins University | Kao S.-C.,Lin Kou Medical Center | Petralia R.S.,U.S. National Institutes of Health | And 3 more authors.
Pain | Year: 2011

Peripheral inflammation alters AMPA receptor (AMPAR) subunit trafficking and increases AMPAR Ca2+ permeability at synapses of spinal dorsal horn neurons. However, it is unclear whether AMPAR trafficking at extrasynaptic sites of these neurons also changes under persistent inflammatory pain conditions. Using patch-clamp recording combined with Ca2+ imaging and cobalt staining, we found that, under normal conditions, an extrasynaptic pool of AMPARs in rat substantia gelatinosa (SG) neurons of spinal dorsal horn predominantly consists of GluR2-containing Ca2+-impermeable receptors. Maintenance of complete Freund's adjuvant (CFA)-induced inflammation was associated with a marked enhancement of AMPA-induced currents and [Ca 2+]i transients in SG neurons, while, as we previously showed, the amplitude of synaptically evoked AMPAR-mediated currents was not changed 24 h after CFA. These findings indicate that extrasynaptic AMPARs are upregulated and their Ca2+ permeability increases dramatically. This increase occurred in SG neurons characterized by intrinsic tonic firing properties, but not in those exhibited strong adaptation. This increase was also accompanied by an inward rectification of AMPA-induced currents and enhancement of sensitivity to a highly selective Ca2+-permeable AMPAR blocker, IEM-1460. Electron microcopy and biochemical assays additionally showed an increase in the amount of GluR1 at extrasynaptic membranes in dorsal horn neurons 24 h post-CFA. Taken together, our findings indicate that CFA-induced inflammation increases functional expression and proportion of extrasynaptic GluR1-containing Ca2+-permeable AMPARs in tonically firing excitatory dorsal horn neurons, suggesting that the altered extrasynaptic AMPAR trafficking might participate in the maintenance of persistent inflammatory pain. Persistent peripheral inflammation increases functional expression and proportion of extrasynaptic GluR1-containing Ca2+-permeable AMPARs within their entire pool specifically in tonically firing SG neurons. © 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved. Source

Chang C.-C.,Chang Gung University | Chang C.-Y.,Chang Gung University | Wu Y.-T.,Chang Gung University | Huang J.-P.,Chang Gung University | And 2 more authors.
Journal of Biomedical Science | Year: 2011

Background: Diabetic nephropathy (DN) has been recognized as the leading cause of end-stage renal disease. Resveratrol (RSV), a polyphenolic compound, has been indicated to possess an insulin-like property in diabetes. In the present study, we aimed to investigate the renoprotective effects of RSV and delineate its underlying mechanism in early-stage DN. Methods. The protective effects of RSV on DN were evaluated in streptozotocin (STZ)-induced diabetic rats. Results: The plasma glucose, creatinine, and blood urea nitrogen were significantly elevated in STZ-induced diabetic rats. RSV treatment markedly ameliorated hyperglycemia and renal dysfunction in STZ-induced diabetic rats. The diabetes-induced superoxide anion and protein carbonyl levels were also significantly attenuated in RSV-treated diabetic kidney. The AMPK protein phosphorylation and expression levels were remarkably reduced in diabetic renal tissues. In contrast, RSV treatment significantly rescued the AMPK protein expression and phosphorylation compared to non-treated diabetic group. Additionally, hyperglycemia markedly enhanced renal production of proinflammatory cytokine IL-1. RSV reduced IL-1 but increased TNF- and IL-6 levels in the diabetic kidneys. Conclusions: Our findings suggest that RSV protects against oxidative stress, exhibits concurrent proinflammation and anti-inflammation, and up-regulates AMPK expression and activation, which may contribute to its beneficial effects on the early stage of DN. © 2011 Chang et al; licensee BioMed Central Ltd. Source

Lee C.-H.,Kaohsiung Medical Center | Lee C.-H.,Chang Gung University | Su L.-H.,Lin Kou Medical Center | Su L.-H.,Chang Gung University | And 5 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2010

Bacteremias caused by Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL-KP; n = 52) and producing both ESBL and AmpC-type DHA-1 beta-lactamase (ESBL-PMABL-KP; n = 20) were analyzed. Higher MIC50s and MIC90s for carbapenems, ciprofloxacin, and piperacillin- tazobactam were observed with ESBL-PMABL-KP than with ESBL-KP. Patients with oxyimino-β-lactam exposure and high modified Pitt bacteremia scores (HMPBSs) were at higher risk, while those with piperacillin-tazobactam and aminoglycoside exposure were at lower risk for ESBL-KP bacteremia. Patients with fluoroquinolone exposure, diabetes mellitus, and HMPBS were at higher risk, while those with aminoglycoside exposure were at lower risk, for ESBL-PMABL-KP bacteremia. Copyright © 2010, American Society for Microbiology. All Rights Reserved. Source

Lu H.-E.,Food Industry Research and Development Institute | Lu H.-E.,National Chiao Tung University | Tsai M.-S.,Prenatal Diagnosis Center | Tsai M.-S.,Fu Jen Catholic University | And 6 more authors.
Experimental Cell Research | Year: 2011

Generation of induced pluripotent stem (iPS) cells from somatic cells has been successfully achieved by ectopic expression of four transcription factors, Oct4, Sox2, Klf4 and c-Myc, also known as the Yamanaka factors. In practice, initial iPS colonies are picked based on their embryonic stem (ES) cell-like morphology, but often may go on to fail subsequent assays, such as the alkaline phosphate (AP) assay. In this study, we co-expressed through lenti-viral delivery the Yamanaka factors in amniotic fluid-derived (AF) cells. ES-like colonies were picked onto a traditional feeder layer and a high percentage AF-iPS with partial to no AP activity was found. Interestingly, we obtained an overwhelming majority of fully stained AP positive (AP+) AF-iPS colonies when colonies were first seeded on a feeder-free culture system, and then transferred to a feeder layer for expansion. Furthermore, colonies with no AP activity were not detected. This screening step decreased the variation seen between morphology and AP assay. We observed the AF-iPS colonies grown on the feeder layer with 28% AP+ colonies, 45% AP partially positive (AP+/-) colonies and 27% AP negative (AP-) colonies, while colonies screened by the feeder-free system were 84% AP+ colonies, 16% AP+/- colonies and no AP- colonies. The feeder-free screened AP+ AF-iPS colonies were also positive for pluripotent markers, OCT4, SOX2, NANOG, TRA-1-60, TRA-1-81, SSEA-3 and SSEA-4 as well as having differentiation abilities into three germ layers in vitro and in vivo. In this study, we report a simplistic, one-step method for selection of AP+ AF-iPS cells via feeder-free screening. © 2011 Elsevier Inc. Source

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