Albanin A, Derived from the Root Bark of Morus alba L., Depresses Glutamate Release in the Rat Cerebrocortical Nerve Terminals via Ca2+/Calmodulin/Adenylate Cyclase 1 Suppression

Yi Chang,Chi-Feng Hung,Horng Huey Ko,Su-Jane Wang 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.3

Decreasing synaptic release of glutamate may counteract glutamate excitotoxicity in many neurological diseases. In this study, we investigated the effect of albanin A, a constituent in the root bark of Morus alba L., on the release of glutamate in rat cerebral cortex nerve endings (synaptosomes). We found that albanin A at 5–30μM suppressed 4-aminopyridine (4-AP)-induced release of glutamate. This phenomenon was abolished by extracellular calcium removal or by vesicular transporter inhibition, and was associated with a decrease in intrasynaptosomal Ca2+ levels. However, albanin A had no effect on the synaptosomal membrane potential. The inhibition of N- and P/Q-type Ca2+ channels, calmodulin, adenylate cyclase (AC), and protein kinase A, abolished the effect of albanin A on the glutamate release evoked by 4-AP. Moreover, the albanin A-mediated inhibition of glutamate release was prevented by the Ca2+/calmodulin-stimulated AC1 inhibitor. Western blot showed that AC1, but not AC8, was presented in the synaptosomes, and albanin A reduced 4-AP-induced increases in synaptosomal cyclic adenosine monophosphate content. In addition, albanin A pretreatment substantially attenuated neuronal damage in a rat model of kainic acid-induced glutamate excitotoxicity. Our data reveal that albanin A suppresses glutamate release by decreasing Ca2+/calmodulin/AC1 activation in synaptosomes and exerts neuroprotective effect in vivo.

Myricetin Inhibits the Release of Glutamate in Rat Cerebrocortical Nerve Terminals

Yi Chang,Chia-Ying Chang,Su-Jane Wang,Shu-Kuei Huang 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.5

The excessive release of glutamate is a critical element in the neuropathology of acute and chronic brain disorders. The purpose of the present study was to investigate the effect and possible mechanism of myricetin, a naturally occurring flavonoid with a neuroprotective profile, on endogenous glutamate release in the nerve terminals (synaptosomes) of the rat cerebral cortex. The release of glutamate was evoked by the K+ channel blocker 4-aminopyridine (4-AP) and measured by one-line enzyme-coupled fluorometric assay. We also used a membrane potential-sensitive dye to assay the synaptosomal plasma membrane potential, and a Ca2 + indicator Fura-2 to monitor cytosolic Ca2 + concentrations ([Ca2 + ]C). Results show that myricetin inhibited 4-AP-evoked glutamate release, and this effect was prevented by chelating extracellular Ca2 + ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor dl-threo-beta-benzyl-oxyaspartate had no effect on myricetin action. Myricetin did not alter the synaptosomal membrane potential, but decreased 4-APinduced increases in the cytosolic free Ca2 + concentration. Furthermore, the myricetin effect on 4-AP-evoked glutamate release was prevented by blocking the Cav2.2 (N-type) and Cav2.1 (P/Q-type) channels, but not by blocking intracellular Ca2 + release. These results suggest that myricetin inhibits glutamate release from cerebrocortical synaptosomes by attenuating voltage-dependent Ca2 + entry. This implies that the inhibition of glutamate release is an important pharmacological activity of myricetin that may play a critical role in the apparent clinical efficacy of this compound.

Preparation of Highly Ordered Anodic Aluminum Oxide Membranes with Wide-Range Tunable Pore Intervals in Mixed Electrolytes

Yi Chang,Zhiyuan Ling 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.5

Highly ordered anodic aluminum oxide (AAO) membranes with pore interval from 100 nm to 520 nm were fabricated successfully in the mixed electrolytes, which are composed of 0.3 M oxalic acid and 1 wt.% phosphoric acid/0.01 M aluminum oxalate. The study results show that oxalic acid volume percentage has an approximate linear relationship with the optimal anodic oxidation voltage. The optimal anodic oxidation voltage is basically equal to the critical oxidation voltage. The theoretical analysis suggests that the anodic oxidation current is closely related to the ionization constants of acid radical ion in the electrolyte. Since the secondary ionization constant of oxalic radical ion is greater than that of phosphoric acid radical ion, the optimal anodic oxidation voltage increases and the steady anodic oxidation current decreases with the decrease of oxalic acid volume percent.

Analysis of the Efficient Utilization of Surplus Parking Spaces in Apartment Complexes of Seoul

Yi, Chang,Lee, Donghoon 한국생태환경건축학회 2016 한국생태환경건축학회 논문집 Vol.16 No.5

중국의 정부개혁 구조

Liu Yichang 한국행정학회 1995 한국행정학회 학술발표논문집 Vol.1995 No.-

Design and Preparation of Magnetic CTAB/Montmorillonite Nanocomposite for Phenols Removal

Rong Shen,Yichang Yu,Yue Wang,Zhining Xia 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.10

The cetyltrimethyl ammonium bromide (CTAB)-modified montmorillonite (MMT) was synthesized via a novel "dissolution and reassembly" method. To determine the optimal formula, the adsorption of C.I. Reactive Red 2 (X3B) with CTAB/MMT was investigated. The optimal CTAB/MMT nanocomposite was used to remove 2,6-dichlorophenol and p-nitrophenol from aqueous solutions. The adsorption results can be described by Langmuir isotherm, and the adsorption capacities were 200 mg/g and 125 mg/g for 2,6-dichlorophenol and p-nitrophenol, respectively. To realize the quick separation and recycle, the magnetic CTAB/MMT was further strategized and synthesized. The adsorption equilibrium time was 15 min for both contaminants; the ions' strength showed a little bit of influence on the adsorption performance. In addition, compared with acidic condition, neutral condition was more beneficial to the adsorption reaction. Due to the addition of Fe3O4, the adsorption capacities of this magnetic nanocomposite for 2,6-dichlorophenol and p-nitrophenol were a little bit decreased, which were 170 mg/g and 91 mg/g, respectively. However, the magnetic nanocomposite can be separated within 30s under an external magnetic field, which would be useful in the practical application.

Catalpol Inhibits Tregs-to-Th17 Cell Transdifferentiation by Up-Regulating Let-7g-5p to Reduce STAT3 Protein Levels

Lingling Zhou,Yuxi Di,Mingfei Zhang,Yichang Chen,Ruonan Sun,Meiyu Shen,Fengxiang Tian,Pei Yang,Feiya Qian 연세대학교의과대학 2022 Yonsei medical journal Vol.63 No.1

Purpose: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease, and Th17 cells are key factors in the pathogenesis of human inflammatory conditions, such as RA. Catalpol (CAT), a component in Rehmanniae Radix (RR), has been found to regulate human immunity. However, the effects of CAT on Th17 cell differentiation and improvement of RA are not clear. Materials and Methods: Collagen-induced arthritis (CIA) mice were constructed to detect the effects of CAT on arthritis and Th17 cells. The effect of CAT on Th17 differentiation was evaluated with let-7g-5p transfection experiments. Flow cytometry was used to detect the proportion of Th17 cells after CAT treatment. Levels of interleukin-17 and RORγt were assessed by qRT-PCR and enzyme-linked immunosorbent assay. The expression of signal transducer and activator of transcription 3 (STAT3) was determined by qRT-PCR and Western blot. Results: We found that the proportion of Th17 cells was negatively associated with let-7g-5p expression in CIA mice. In in vitro experiments, CAT suppressed traditional differentiation of Th17 cells. Simultaneously, CAT significantly decreased Tregs-to-Th17 cells transdifferentiation. Our results demonstrated that CAT inhibited Tregs-to-Th17 cells transdifferentiation by up-regulating let-7g-5p and that the suppressive effect of CAT on traditional differentiation of Th17 cells is not related with let-7-5p. Conclusion: Our data indicate that CAT may be a potential modulator of Tregs-to-Th17 cells transdifferentiation by up-regulating let-7g-5p to reduce the expression of STAT3. These results provide new directions for research into RA treatment.

High-performance ZIF-302 mixed-matrix membranes for efficient CO2 capture

Junfeng Qian,Eryue Song,Haiqian Lian,Jinlong Jiang,Chongqing Wang,Yichang Pan 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

High-performance mixed matrix membranes (MMMs) were developed to assist in controlling global warmingby capturing carbon dioxide (CO2) from moist flue gas. However, the separation performance of MMMs has alwaysbeen limited by gas permeability and long-term operating stability under humid conditions. ZIF-302 is a novel chabazite(CHA) topology structure with hydrophobic ligand. Herein, uniform ZIF-302 nanocrystals were doped into theP84 polymer matrix to synthesize different content of defect-free ZIF-302/P84 MMMs for CO2/N2 separation. A significantcombination of gas permeability and separation factors was found in MMMs with a ZIF-302 packing load of 30wt%. The gas permeability of CO2 and the separation factor of CO2/N2 were significantly increased to 5.2 Barrers and46, respectively, which breaks the trade-off between permeability and selectivity of the polymer membrane. In addition,the long-term operation stability showed that the separation performance of ZIF-302/P84 MMMs for CO2/N2 was maintainedmore than 30 h at 3 bar and 60 oC. The main characteristics of the MMMs prepared in this paper include the combinationof favorable structural stability under humid conditions and unaffected CO2/N2 gas separation performance.