Selenium-Containing Protein From Selenium-Enriched Spirulina platensis Attenuates Cisplatin-Induced Apoptosis in MC3T3-E1 Mouse Preosteoblast by Inhibiting Mitochondrial Dysfunction and ROS-Mediated Oxidative Damage

Accumulated evidences have verified that cancer chemotherapy may increase the risk of osteoporosis and severely affected the life quality. Osteoclasts hyperactivation was commonly accepted as the major pathogenesis of osteoporosis. However, the role of osteoblasts dysfunction in osteoporosis was little investigated. Our previous study has confirmed that selenium-containing protein from selenium-enriched Spirulina platensis (Se-SP) exhibited enhanced hepatoprotective potential through inhibiting oxidative damage. Herein, the protective effect of Se-SP against cisplatin-induced osteoblasts dysfunction in MC3T3-E1 mouse preosteoblast was investigated, and the underlying mechanism was evaluated. The results indicated that cisplatin dramatically decreased cell viability of preosteoblast by triggering mitochondria-mediated apoptosis pathway. Cisplatin treatment also caused mitochondrial dysfunction and reactive oxide species (ROS)-mediated oxidative damage. However, Se-SP pre-treatment effectively prevented MC3T3-E1 cells from cisplatin-induced mitochondrial dysfunction by balancing Bcl-2 family expression and regulating the opening of mitochondrial permeability transition pore (MPTP), attenuated cisplatin-induced oxidative damage through inhibiting the overproduction of ROS and superoxide anion, and eventually reversed cisplating-induced early and late apoptosis by inhibiting PARP cleavage and caspases activation. Our findings validated that Se-SP as a promising Se species could be a highly effective way in the chemoprevention and chemotherapy of oxidative damage-mediated bone diseases

Highly Selective Electrochemiluminescence Chemosensor for Sulfide Enabled by Hierarchical Reactivity

Hydrogen sulfide (H2S) is a well-known toxic gas with the odor of rotten eggs. Several reaction-based electrochemiluminescence (ECL) chemosensors for H2S have been developed; however, no homogeneous ECL probe with high selectivity toward H2Sinaqueous media has been reported. Herein, we report an iridium(III) complex-based ECLchemodosimetric probe employing two 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) groups known as a photo-induced electron transfer quencher and a reaction site for the selective detection of H2S; the detection mechanism involves H2S being clearly distinguished frombiothiols based on the different cleavage rates of the two NBD groups and extremely weakECL interferences caused by reaction by-products. The probe was rationally designed toimprove selectivity toward H2S within the ECL analysis platform by enabling the removal of nonspecific background signals observedvia fluorescence analysis. This analytical system exhibited remarkable selectivity toward H2S, a rapid reaction rate, and high sensitivity (LOD= 57 nM) compared to conventional fluorescence methods. Furthermore, the probe could successfully quantify H2S in tap water samples and commercial ammonium sulfide solutions ,which demonstrates the effectiveness of this probe infield monitoring.N

Discrimination of Redox-Responsible Biomolecules by a Single Molecular Sensor

A new application of a fluorescent sensor (PyDPA) for the discrimination of redox-responsible molecules is reported. Nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NAD⁺/NADP⁺) and flavin mononucleotide/flavin adenine dinucleotide (FMN/FAD) were differentiated by means of ratiometric fluorescence change from excimer–monomer equilibrium and time-dependent fluorescence change, respectively

Real-time monitoring of S-adenosyl-L-homocysteine hydrolase using a chemodosimetric fluorescence "turn-on" sensor

Although various methods have been used to measure the activity of S-adenosyl-L-homocysteine hydrolase (SAHase), most of them are rather complex, expensive, and not suitable for routine analysis. Herein, we describe simple fluorescence monitoring for SAHase activity using a synthetic probe that undergoes chemical binding selectively with L-homocysteine (Hcy), an enzyme metabolite from SAHase catalysis. The ring formation between the probe and Hcy during the enzyme catalysis is quantified by fluorescent emission from the binding adduct, which provides facile, real-time monitoring for the SAHase activity. The chemodosimetric reaction between the probe and Hcy is similar to 100-fold faster than that for the enzyme catalysis so that it is successfully applicable in SAHase assay.This work was supported by the Basic Science Research Program, the Pioneer Research Program, and the Bio & Medical Technology Development Program through National Research Foundation of Korea (NRF) grants funded by the Ministry of Education, Science, and Technology (MEST) of South Korea (Grant Nos. 2012-0008314, 2012-0080734, and 2012-050100).OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000002410/11SEQ:11PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000002410ADJUST_YN:YEMP_ID:A002014DEPT_CD:458CITE_RATE:3.535FILENAME:real-time monitoring of s-adenosyl-l-homocysteine.pdfDEPT_NM:화학생물공학부EMAIL:[email protected]_YN:NCONFIRM: