摘要：
1. Adipocyte hypertrophy and hyperplasia are important processes in the development of obesity. To understand obesity and its associated diseases, it is important to elucidate the molecular mechanisms governing adipogenesis. MicroRNA‐375 has been shown to inhibit differentiation of neurites, and participate in the regulation of insulin secretion and blood homeostasis. However, it is unknown whether miR‐375 plays a role in adipocyte differentiation. 2. To investigate the role of miR‐375 in adipocyte differentiation, we compared the miR‐375 expression level between 3T3‐L1 pre‐adipocytes and adipocytes using miRNA microarray and quantitative real‐time reverse transcription polymerase chain reaction (qRT‐PCR) analysis. Furthermore, we evaluated the effects of overexpression or inhibition of miR‐375 on 3T3‐L1 adipocyte differentiation. 3. In the present study, we found that miR‐375 expression was increased after induction of adipogenic differentiation. Overexpression of miR‐375 enhanced 3T3‐L1 adipocyte differentiation, as evidenced by its ability to increase mRNA levels of both CCAAT/enhancer binding protein‐α (C/EBPα) and peroxisome proliferator‐activated receptor‐γ (PPARγ2), and induction of adipocyte fatty acid‐binding protein (aP2) and triglyceride (TG) accumulation. Furthermore, we found overexpression of miR‐375 suppressed phosphorylation levels of extracellular signal‐regulated kinases 1/2 (ERK1/2). In contrast, anti‐miR‐375 increased ERK1/2 phosphorylation levels and inhibited mRNA expression of C/EBPα, PPARγ2 and aP2 in 3T3‐L1 adipocyte, accompanied by decreased adipocyte differentiation. 4. Taken together, these data suggest that miR‐375 promotes 3T3‐L1 adipocyte differentiation, possibly through modulating the ERK–PPARγ2–aP2 pathway.
期刊：
The Journal of chemical physics,2011年134(8):084103 ISSN：0021-9606
通讯作者：
Liu, S.(shubin@email.unc.edu)
作者机构：
[Zhong, Ai-Guo] Department of Chemistry, Taizhou College, Linhai Zhejiang 317000, China;[Yang, Qinsong] PT TSG Chemical, Jl. Inspeksi Kalimalang, Sukadanau, Cikarang Barat, Lokasi G II, Sektor 3, Bekasi 17520, Indonesia;[Liu, Shubin] Research Computing Center, University of North Carolina, Chapel Hill, NC 27599-3420, United States;[Huang, Ying] School of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
通讯机构：
[Liu, Shubin] Univ N Carolina, Ctr Res Comp, Chapel Hill, NC 27599 USA.
关键词：
A-density - Anomeric effect - Axial orientations - Conformational space - Cyclohexane ring - D-glucopyranose - Density functionals - Electrostatic interactions - Energy components - Energy differences - Equatorial positions - Exchange-correlations - Heteroatoms - Hyperconjugation effects - Steric hindrances - Strong correlation - Total energy differences - Two-component
摘要：
The anomeric effect (the tendency of heteroatomic substituents adjacent to a heteroatom within the cyclohexane ring to prefer the axial orientation instead of the sterically less hindered equatorial position) is traditionally explained through either the dipole moment repulsion or the hyperconjugation effect. In this work, by employing our recent work in density functional steric analysis, we provide a novel two-component explanation, which is consistent with the common belief in chemistry that the effect has a stereoelectronic origin. With alpha-D-glucopyranose as the prototype, we systematically explore its conformational space and generate 32 isomers, leading to a total of 80 axial-equatorial conformation pairs. The energy difference analysis of these pairs shows that while statistically speaking the tendency is valid, the anomeric effect is not always true and can be violated. Three energy components, exchange-correlation, classical electrostatic, and density functional steric, are found to be directly proportional to the total energy difference between axial and equatorial isomers. We also found that the total dipole moment change, not the hyperconjugation effect, is a reasonable indicator of the total energy difference. However, all these correlations alone are not strong enough to provide a compellingly convincing explanation for the general validity of the effect. With the help of strong correlations between energy components, an explanation with two energy components, steric and electrostatic, was proposed in this work. We show that the axial-equatorial energy difference in general, with the anomeric effect as a special case, is dictated by two factors of the stereoelectronic origin, steric hindrance and classical electrostatic interactions, synchronously working together. Another explanation in terms of exchange-correlation and electrostatic interactions has also been obtained in this work. (C) 2011 American Institute of Physics. [doi:10.1063/1.3555760]
关键词：
adult-onset type II citrullinemia (CTLN2);aspartate-glutamate carrier (AGC);citrin;malate-aspartate shuttle;neonatal intrahepatic cholestatic hepatitis (NICCD);retrotransposal insertion;SLC25A13
摘要：
Deficiency of citrin, liver-type mitochondrial aspartate-glutamate carrier, is an autosomal recessive disorder caused by mutations of the SLC25A13 gene on chromosome 7q21.3 and has two phenotypes: neonatal intrahepatic cholestatic hepatitis (NICCD) and adult-onset type II citrullinemia (CTLN2). So far, we have described 19 SLC25A13 mutations. Here, we report 13 novel SLC25A13 mutations (one insertion, two deletion, three splice site, two nonsense, and five missense) in patients with citrin deficiency from Japan, Israel, UK, and Czech Republic. Only R360X was detected in both Japanese and Caucasian. IVS16ins3kb identified in a Japanese CTLN2 family seems to be a retrotransposal insertion, as the inserted sequence (2,667-nt) showed an antisense strand of processed complementary DNA (cDNA) from a gene on chromosome 6 (C6orf68), and the repetitive sequence (17-nt) derived from SLC25A13 was found at both ends of the insert. All together, 30 different mutations found in 334 Japanese, 47 Chinese, 11 Korean, four Vietnamese and seven non-East Asian families have been summarized. In Japan, IVS16ins3kb was relatively frequent in 22 families, in addition to known mutations IVS11 + 1G > A, 851del4, IVS13 + 1G > A, and S225X in 189, 173, 48 and 30 families, respectively; 851del4 and IVS16ins3kb were found in all East Asian patients tested, suggesting that these mutations may have occurred very early in some area of East Asia.
摘要：
Aldo‐keto reductase 1B10 (AKR1B10) is a secretory protein that is upregulated with tumorigenic transformation of human mammary epithelial cells. This study demonstrated that AKR1B10 was overexpressed in 20 (71.4%) of 28 ductal carcinomas in situ, 184 (83.6%) of 220 infiltrating carcinomas and 28 (87.5%) of 32 recurrent tumors. AKR1B10 expression in breast cancer was correlated positively with tumor size (p = 0.0012) and lymph node metastasis (p = 0.0123) but inversely with disease‐related survival (p = 0.0120). Univariate (p = 0.0077) and multivariate (p = 0.0192) analyses both suggested that AKR1B10, alone or together with tumor size and node status, is a significant prognostic factor for breast cancer. Silencing of AKR1B10 in BT‐20 human breast cancer cells inhibited cell growth in culture and tumorigenesis in female nude mice. Importantly, AKR1B10 in the serum of breast cancer patients was significantly increased to 15.18 ± 9.08 ng/ml [n = 50; 95% confidence interval (CI), 12.60–17.76], with a high level up to 58.4 ng/ml, compared to 3.34 ± 2.27 ng/ml in healthy donors (n = 60; 95% CI, 2.78–3.90). In these patients, AKR1B10 levels in serum were correlated with its expression in tumors (r = 0.8066; p < 0.0001). Together our data suggests that AKR1B10 is overexpressed in breast cancer and may be a novel prognostic factor and serum marker for this deadly disease.
作者：
Ling, H. -y.;Hu, B.;Hu, X. -b.;Zhong, J.;Feng, S. -d.;Qin, L.;Liu, G.;Wen, G. -b.;Liao, D. -f.*
期刊：
Experimental and clinical endocrinology & diabetes : official journal, German Society of Endocrinology [and] German Diabetes Association,2012年120(9):553-559 ISSN：0947-7349
通讯作者：
Liao, D. -f.
作者机构：
[Wen, G. -b.; Zhong, J.] Univ S China, Affiliated Hosp 1, Inst Clin Res, Hengyang, Peoples R China.;[Ling, H. -y.; Hu, B.] Univ S China, Sch Med, Dept Physiol, Hengyang, Peoples R China.;[Ling, H. -y.] Univ S China, Ctr Basic Med Postdoctoral Studies, Hengyang, Peoples R China.;[Qin, L.; Liu, G.] Univ S China, Inst Pharm & Pharmacol, Key Lab Pharmacoprote Hunan Prov, Hengyang, Peoples R China.;[Feng, S. -d.] Univ S China, Sch Publ Hlth, Dept Epidemiol, Hengyang, Peoples R China.
通讯机构：
[Liao, D. -f.] Hunan Univ Chinese Med, State Key Lab Chinese Med Powder & Med Innovat Hu, Div Stem Cell Regulat & Applicat, Changsha 410208, Hunan, Peoples R China.
关键词：
miR-21;insulin resistance;PTEN;AKT
摘要：
Aims/hypothesis: Our previous study showed there was a change of microRNA (miRNA) expression profile, and miR-21 was significantly down regulated in insulin-resistant adipocytes (IR-adipocytes). Phosphatase and tensin homologs deleted on chromosome 10 (PTEN), a negative regulator of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, was identified to be a target gene of miR-21, which suggested miR-21 might be associated with insulin resistance (IR) or diabetes. However, it is not known whether miR-21 play any role in the development of IR in 3T3-L1 adipocytes. Methods: Normal adipocytes and adipocytes transfected with pre-miR-21(pmiR-21) or negative control (pNeg) were treated with high glucose and high insulin for 24 h, insulin-stimulated glucose uptake was determined by 2-Deoxyglucose transport assay, miR-21 expression level was measured by using quantitative real-time RT-PCR (qRT-PCR). The protein expression levels of PTEN, Akt, phospho-Akt (Ser473), IR beta, GSK3 beta, phospho-GSK3 beta (Ser9) and GLUT4 were detected by western blotting assay. Results: We further confirmed that miR-21 was down regulated in IR-adipocytes by qRT-PCR. Over-expression of miR-21 significantly increased insulin-induced glucose uptake and decreased PTEN protein expression, while it had no significant effect on PTEN mRNA expression in IR-adipocytes. Moreover, over-expressing miR-21 significantly increased insulin-induced phosphorylation of AKT (Ser473), GSK3 beta (Ser9) and the translocation of glucose transporter 4 (GLUT4) in IR-adipocytes. Conclusions: In this study, our data demonstrate that miR-21 reverses high glucose and high insulin induced IR in 3T3-L1 adipocytes, possibly through modulating the PTEN-AKT pathway, and miR-21 may be a new therapeutic target for metabolic diseases such as T2DM and obesity.
摘要：
BACKGROUND: Numerous man-made pollutants activate the aryl hydrocarbon receptor (AhR) and are risk factors for type 2 diabetes. AhR signaling also affects molecular clock genes to influence glucose metabolism. OBJECTIVE: We investigated mechanisms by which AhR activation affects glucose metabolism. METHODS: Glucose tolerance, insulin resistance, and expression of peroxisome proliferator activated receptor-alpha (PPAR-alpha) and genes affecting glucose metabolism or fatty acid oxidation and clock gene rhythms were investigated in wild-type (WT) and AhR-deficient [knockout (KO)] mice. AhR agonists and small interfering RNA (siRNA) were used to examine the effect of AhR on PPAR-alpha expression and glycolysis in the liver cell line Hepa-1c1c7 (c7) and its c12 and c4 derivatives. Brain, muscle ARNT-like protein 1 (Bmal1) siRNA and Ahr or Bmal1 expression plasmids were used to analyze the effect of BMAL1 on PPAR-alpha expression in c7 cells. RESULTS: KO mice displayed enhanced insulin sensitivity and improved glucose tolerance, accompanied by decreased PPAR-alpha and key gluconeogenic and fatty acid oxidation enzymes. AhR agonists increased PPAR-alpha expression in c7 cells. Both Ahr and Bmal1 siRNA reduced PPAR-alpha and metabolism genes. Moreover, rhythms of BMAL1 and blood glucose were altered in KO mice. CONCLUSIONS: These results indicate a link between AhR signaling, circadian rhythms, and glucose metabolism. Furthermore, hepatic activation of the PPAR-alpha pathway provides a mechanism underlying AhR-mediated insulin resistance.
摘要：
The aryl hydrocarbon receptor (AhR) is a period-aryl hydrocarbon receptor nuclear transporter-simple minded domain transcription factor that shares structural similarity with circadian clock genes and readily interacts with components of the molecular clock. Activation of AhR by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters behavioral circadian rhythms and represses the Period1 (Per1) gene in murine hematopoietic stem and progenitor cells. Per1 expression is driven by circadian locomotor activity cycles kaput-brain muscle ARNT-like (CLOCK-BMAL1)-dependent activation of Eboxes in the Per1 promoter. We hypothesized that the effects of AhR activation on the circadian clock are mediated by disruption of CLOCK-BMAL1 function and subsequent Per1 gene suppression. Effects of AhR activation on rhythmic Per1 transcripts were examined in livers of mice after treatment with the AhR agonist, TCDD; the molecular mechanisms of Per1 repression by AhR were determined in hepatoma cells using TCDD and beta-napthoflavone as AhR activators. This study reports, for the first time, that AhR activation by TCDD alters the Per1 rhythm in the mouse liver and that Per1 gene suppression depends upon the presence of AhR. Furthermore, AhR interaction with BMAL1 attenuates CLOCK-BMAL1 activity and decreases CLOCK binding at Ebox1 and Ebox3 in the Per1 promoter. Taken together, these data suggest that AhR activation represses Per1 through disrupting CLOCK-BMAL1 activity, producing dysregulation of rhythmic Per1 gene expression. These data define alteration of the Per1 rhythm as novel signaling events downstream of AhR activation. Downregulation of Per1 could contribute to metabolic disease, cancer, and other detrimental effects resulting from exposure to certain environmental pollutants.
摘要：
Nasopharyngeal carcinoma (NPC) has the highest metastasis rate among head and neck cancers with unclear mechanism. WNT5A belongs to the WNT family of cysteine-rich secreted glycoproteins. Our previous high-throughput gene expression profiling revealed that WNT5A was up-regulated in highly metastatic cells. In the present study, we first confirmed the elevated expression of WNT5A in metastatic NPC tissues at both the mRNA and protein levels. We then found that WNT5A promoted epithelial-mesenchymal transition (EMT) in NPC cells, induced the accumulation of CD24-CD44+ cells and side population, which are believed to be cancer stem cell characteristics. Moreover, WNT5A promoted the migration and invasion of NPC cells in vitro, while in vivo treatment with recombinant WNT5A promoted lung metastasis. Knocking down WNT5A diminished NPC tumorigenesis in vivo. When elevated expression of WNT5A coincided with the elevated expression of vimentin in the primary NPC, the patients had a poorer prognosis. Among major signaling pathways, protein kinase C (PKC) signaling was activated by WNT5A in NPC cells. A positive feedback loop between WNT5A and phospho-PKC to promote EMT was also revealed. Taken together, these data suggest that WNT5A is an important molecule in promoting stem cell characteristics in NPC, leading to tumorigenesis and metastasis.
期刊：
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES,2014年15(5):8335-8351 ISSN：1422-0067
通讯作者：
Liao, Duan-Fang
作者机构：
[Zhou, Fang-Liang] Division of Stem Cell Regulation and Application, College of Medicine, Hunan University of Traditional Chinese Medicine, Changsha 410208, China. zhoufangliang305@163.com;[He, Ying-Chun] Division of Stem Cell Regulation and Application, College of Medicine, Hunan University of Traditional Chinese Medicine, Changsha 410208, China. yingchunhe@aliyun.com;[Shen, Yi] Department of Medical Microbiology, Immunology & Cell Biology, Simmons Cancer Institute, Southern Illinois University School of Medicine, 913 N, Rutledge Street, Springfield, IL 62702, USA. yshen@siumed.edu;[Liao, Duan-Fang] Division of Stem Cell Regulation and Application, College of Medicine, Hunan University of Traditional Chinese Medicine, Changsha 410208, China. dfliao66@aliyun.com;[Cao, Deliang] Division of Stem Cell Regulation and Application, College of Medicine, Hunan University of Traditional Chinese Medicine, Changsha 410208, China. dcao@siumed.edu
通讯机构：
[Liao, Duan-Fang] Hunan Univ Tradit Chinese Med, Coll Med, Div Stem Cell Regulat & Applicat, Changsha 410208, Hunan, Peoples R China.
关键词：
cancer stem cells;side population;apoptosis;apoptotic inducers;apoptotic death pathways;cancer therapy
摘要：
Cancer stem cells (CSCs) play crucial roles in tumor progression, chemo- and radiotherapy resistance, and recurrence. Recent studies on CSCs have advanced understanding of molecular oncology and development of novel therapeutic strategies. This review article updates the hypothesis and paradigm of CSCs with a focus on major signaling pathways and effectors that regulate CSC apoptosis. Selective CSC apoptotic inducers are introduced and their therapeutic potentials are discussed. These include synthetic and natural compounds, antibodies and recombinant proteins, and oligonucleotides.
摘要：
A bacteriocin-producing lactic acid bacteria, FX-6, was isolated from Tibetan kefir using the agar well diffusion assay. Strain FX-6 was identified as Lactobacillus paracasei subsp. tolerans on the basis of 16S rDNA sequence analyses. This bacteriocin, which was designated bacteriocin Fl, was purified by a threestep purification procedure. The molecular mass of bacteriocin Fl was 2113.842 Da by MALDI-TOF MS analyses. It was also discovered to have blocked N-termini, hampering analysis by Edman degradation. Bacteriocin Fl exhibited a wide range of antimicrobial activity, strong heat stability (20minat 121 C, or 60 min at 100 degrees C) and pH stability (pH 3.0-9.0). Following treatment by pepsin and trypsin, the antibacterial activity was partly reduced. Bacteriocin Fl is the first reported bacteriocin produed by L paracasei subsp. tolerans which can not only inhibit fungi but also bacteria. The characterization of bacteriocin Fl suggested that it was a novel bacteriocin with potential research and application value in food industry. (C) 2014 Elsevier Ltd. All rights reserved.
期刊：
The journal of physical chemistry. A,2008年112(2):305-311 ISSN：1089-5639
通讯作者：
Xiao, M.(xmxiao@hunnu.edu.cn)
作者机构：
[Chunying Rong,†; Ying Huang,†,‡; Xiaoming Xiao,*,† and; Shubin Liu*,†,‖] College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China;[Aiguo Zhong,§] Department of Chemistry, Taizhou College, Linhai, Zhejiang 317000, China;[Shubin Liu*,†,‖] Renaissance Computing Institute, University of North Carolina, Chapel Hill, NC 27599-3455;[Ying Huang,†,‡] School of Pharmacy, Hunan University of Traditional Chinese Medicine, Changsha, Hunan 410007, China
通讯机构：
[Xiao, Xiaoming] Hunan Normal Univ, Coll Chem & Chem Engn, Changsha 410081, Hunan, Peoples R China.
关键词：
Bonding interactions - Chemical reactivity indices - Hemoproteins - Nucleophilic reactions
摘要：
Porphyrin and pincer complexes are both important categories of compounds in biological and catalytic systems. The idea to combine them is computationally investigated in this work. By employment of density functional theory (DFT), conceptual DFT, and time-dependent DFT approaches, structure, spectroscopy, and reactivity properties of porphyrin pincers are systematically studied for a selection of divalent metal ions. We found that the porphyrin pincers are structurally and spectroscopically different from their precursors and are more reactive in electrophilic and nucleophilic reactions. A few quantitative linear/exponential relationships have been discovered between bonding interactions, charge distributions, and DFT chemical reactivity indices. These results are implicative in chemical modification of hemoproteins and understanding chemical reactivity in heme-containing and other biologically important complexes and cofactors.
作者机构：
[Gu, Hong-Feng; Tang, Ya-Ling] Department of Physiology & Institute of Neuroscience, University of South China, Hengyang, People's Republic of China;[Gu, Hong-Feng; Zheng, Xi-Long; Tong, Qiao-Zhen] Division of Stem Cell Regulation and Application, State Key Laboratory of Chinese Medicine Powder and Medicine Innovation in Hunan, Hunan University of Chinese Medicine, Changsha, People's Republic of China;[Jing, Kai-Quan; Nie, Ya-Xiong; Zeng, Yang] Department of Neurology of the First Affiliated Hospital, University of South China, Hengyang, People's Republic of China;[Zheng, Xi-Long] Smooth Muscle Research Group, Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute of Alberta, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada;[Liao, Duan-Fang] Division of Stem Cell Regulation and Application, State Key Laboratory of Chinese Medicine Powder and Medicine Innovation in Hunan, Hunan University of Chinese Medicine, Changsha,Poeple's Republic of China
摘要：
Epigallocatechin gallate (EGCG) is a major polyphenol in green tea with beneficial effects on the impairment in learning and memory. Autophagy is a cellular process that protects neurons from stressful conditions. The present study was designed to investigate whether EGCG can rescue chronic unpredictable mild stress (CUMS)-induced cognitive impairment in rats and whether its protective effect involves improvement of autophagic flux. As expected, our results showed that CUMS significantly impaired memory performance and inhibited autophagic flux as indicated by elevated LC3-II and p62 protein levels. At the same time, we observed an increased neuronal loss and activated mammalian target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70S6k) signaling in the CA1 regions. Interestingly, chronic treatment with EGCG (25 mg/kg, i.p.) significantly improved those behavioral alterations, attenuated histopathological abnormalities in hippocampal CA1 regions, reduced amyloid beta1-42 (A beta(1-42)) levels, and restored autophagic flux. However, blocking autophagic flux with chloroquine, an inhibitor of autophagic flux, reversed these effects of EGCG. Taken together, these findings suggest that the impaired autophagy in CA1 regions of CUMS rats may contribute to learning and memory impairment. Therefore, we conclude that EGCG attenuation of CUMS-induced learning and memory impairment may be through rescuing autophagic flux.
摘要：
A reverse phase ultra-performance liquid chromatography coupled with evaporative light scattering detection (UPLC-ELSD) method Was Successfully established for simultaneous determination of five bile acid derivatives in Calculus Bovis and its medicinal preparations using a Waters Acquity UPLC T3 C-18 column (2.1 x 50 mm, 1.8 mu m) with gradient elution of 0.2% aqueous formic acid and acetonitrile. The influence of liquid flow-rate and column temperature, gas flow-rate and drift tube temperature on resolution was investigated to get the optimized parameters and conditions. This method was validated according to the regulatory guidelines with respect to precision, accuracy and linearity. Under optimum conditions, the five analytes were baseline separated in 11 min with detection and Quantification limits ranged in 10-6.0 ng and 6.0-18.0 ng, respectively, which provided about a twofold reduction in analysis time and good efficiency and sensitivity by comparing a conventional high performance liquid chromatography (HPLC) method. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.
摘要：
Cholesterol efflux from lipid-loaded cells is a key athero-protective event that counteracts cholesterol uptake. The imbalance between cholesterol efflux and uptake determines the prevention or development of atherosclerosis. Many proteins and factors participate in the cholesterol efflux event. However, there are currently no systematic models of reverse cholesterol transport (RCT) that include most RCT-related factors and events. On the basis of recent research findings from other and our laboratories, we propose a novel model of one center and four systems with coupling transportation and networking regulation. This model represents a common way of cholesterol efflux; however, the systems in the model consist of different proteins/factors in different cells. In this review, we evaluate the novel model in vascular smooth muscle cells (VSMCs) and macrophages, which are the most important original cells of foam cells. This novel model consists of 1) a caveolae transport center, 2) an intracellular trafficking system of the caveolin-1 complex, 3) a transmembrane transport system of the ABC-A1 complex, 4) a transmembrane transport system of the SR-B1 complex, and 5) an extracelluar trafficking system of HDL/Apo-A1. In brief, the caveolin-1 system transports cholesterol from intracellular compartments to caveolae. Subsequently, both ABC-A1 and SR-B1 complex systems transfer cholesterol from caveolae to extracellular HDL/Apo-A1. The four systems are linked by a regulatory network. This model provides a simple and concise way to understand the dynamic process of atherosclerosis.
作者机构：
[Zhang, Lida] Zhejiang Chinese Medical University, Hangzhou, Zhejiang Province 310053, China;[Jiang, Xingming] School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China;[Han, Jiangwei] College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China
通讯机构：
[Zhang, Lida] Zhejiang Chinese Med Univ, Hangzhou 310053, Zhejiang, Peoples R China.
摘要：
Reperfusion therapy is widely used to treat acute myocardial infarction (AMI). However, further injury to the heart induced by rapidly initiating reperfusion is often encountered in clinical practice. A lack of pharmacological strategies in clinics limits the prognosis of patients with myocardial ischemia-reperfusion injury (MIRI). Dihydromyricetin (DMY) is one of the most abundant components in vine tea, commonly known as the tender stems and leaves of Ampelopsis grossedentata. The aim of this study was to evaluate the cardioprotection of DMY against myocardial ischemia-reperfusion (I/R) injury and to further investigate the underlying mechanism. An I/R injury was induced by left anterior descending coronary artery occlusion in adult male rats in vivo and a hypoxia-reoxygenation (H/R) injury in H9c2 cardiomyocytes in vitro. We found that DMY pretreatment provided significant protection against I/R-induced injury, including enhanced antioxidant capacity and inhibited apoptosis in vivo and in vitro. This effect correlated with the activation of the PI3K/Akt and HIF-1alpha signaling pathways. Conversely, blocking Akt activation with the PI3K inhibitor LY294002 effectively suppressed the protective effects of DMY against I/R-induced injury. In addition, the PI3K inhibitor partially blocked the effects of DMY on the upregulation of Bcl-2, Bcl-xl, procaspase-3, -8, and -9 protein expression and the downregulation of HIF-1alpha, Bnip3, Bax, Cyt-c, cleaved caspase-3, -8, and -9 protein expression. Collectively, these results showed that DMY decreased the apoptosis and necrosis by I/R treatment, and PI3K/Akt and HIF-1alpha plays a crucial role in protection during this process. These observations indicate that DMY has the potential to exert cardioprotective effects against I/R injury and the results might be important for the clinical efficacy of AMI treatment.
作者机构：
[Li, Kai] Suzhou Univ, Mol Med Ctr, Suzhou 215004, Peoples R China.;[Li, Kai] Suzhou Univ, Affiliated Hosp 2, Suzhou 215004, Peoples R China.;[Tang, Chao-ke; Liao, Duan-fang; Sun, Shao-wei] Univ S China, Life Sci Res Ctr, Key Lab Atherosclerol Hunan Prov, Hengyang 421001, Peoples R China.;[Chen, Lin-xi; Liao, Duan-fang; Lei, Xiao-yong; Tuo, Qin-hui; Sun, Shao-wei; Zu, Xu-yu] Univ S China, Inst Pharm & Pharmacol, Prov Key Lab Pharmacoprotom, Hengyang 421001, Peoples R China.;[Liao, Duan-fang] Hunan Univ Chinese Med, Dept Tradit Chinese Diagnost, Sch Pharm, Changsha 410208, Hunan, Peoples R China.
通讯机构：
[Tang, Chao-ke] Univ S China, Life Sci Res Ctr, Key Lab Atherosclerol Hunan Prov, Hengyang 421001, Peoples R China.
关键词：
caveolae;caveolin-1;oxidized low density lipoprotein;atherosclerosis;transcytosis;human umbilical vein endothelial cells
摘要：
Aim: To explore the mechanisms involved in ox-LDL transcytosis across endothelial cells and the role of caveolae in this process. Methods: An in vitro model was established to investigate the passage of oxidized low density lipoprotein (ox-LDL) through a tight monolayer of human umbilical vein endothelial cells (HUVEC) cultured on a collagen-coated filter. Passage of Dil-labeled ox-LDL through the monolayer was measured using a fluorescence spectrophotometer. The uptake and efflux of ox-LDL by HUVEC were determined using fluorescence microscopy and HPLC. Results: Caveolae inhibitors - carrageenan (250 mu g/mL), filipin (5 mu g/mL), and nocodazole (33 mu mol/L)-decreased the transport of ox-LDL across the monolayer by 48.9%, 72.4%, and 79.8% as compared to the control group. In addition, they effectively decreased ox-LDL uptake and inhibited the efflux of ox-LDL. Caveolin-1 and LOX-1 were up-regulated by ox-LDL in a time-dependent manner and decreased gradually after depletion of ox-LDL (P<0.05). After treatment HUVEC with ox-LDL and silencing caveolin-1, NF-kappa B translocation to the nucleus was blocked and LOX-1 expression decreased (P<0.05). Conclusion: Caveolae can be a carrier for ox-LDL and may be involved in the uptake and transcytosis of ox-LDL by HUVEC.
摘要：
AKR1B10 (aldo-keto reductase family 1, member B10) protein is primarily expressed in normal human small intestine and colon, but overexpressed in several types of human cancers and considered as a tumour marker. In the present study, we found that AKR1B10 protein is secreted from normal intestinal epithelium and cultured cancer cells, as detected by a newly developed sandwich ELISA and Western blotting. The secretion of AKR1B10 was not affected by the protein-synthesis inhibitor cycloheximide and the classical protein-secretion pathway inhibitor brefeldin A, but was stimulated by temperature, ATP, Ca(2+) and the Ca(2+) carrier ionomycin, lysosomotropic NH(4)Cl, the G-protein activator GTP gamma S and the G-protein coupling receptor N-formylmethionyl-leucyl-phenylalanine. The ADP-ribosylation factor inhibitor 2-(4-fluorobenzoylamino)-benzoic acid methyl ester and the phospholipase C inhibitor U73122 inhibited the secretion of AKR1B10. In cultured cells, AKR1B10 was present in lysosomes and was secreted with cathepsin D, a lysosomal marker. In the intestine, AKR1B10 was specifically expressed in mature epithelial cells and secreted into the lumen at 188.6-535.7 ng/ml of Heal fluids (mean = 298.1 ng/ml, 17 = 11). Taken together, our results demonstrate that AKR1B10 is a new secretory protein belonging to a lysosome-mediated non-classical protein-secretion pathway and is a potential serum marker.
期刊：
Journal of Hazardous Materials,2010年179(1-3):742-747 ISSN：0304-3894
通讯作者：
Xiao, X.(kongwj302@126.com)
作者机构：
[Zhao, Yanling; Kong, Weijun; Xiao, Xiaohe; Liu, Wei; Zhang, Ping; Jin, Cheng; Li, Xing-Feng] China Military Institute of Chinese Materia Medica, 302 Military Hospital of China, Beijing 100039, China;[Kong, Weijun; Li, Zulun] Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China;[Liu, Wei] Pharmacy College, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China;[Li, Xing-Feng] Pharmacy College, Hunan University of Traditional Chinese Medicine, Changsha 410208, China
通讯机构：
[Xiao, XH] 302 Mil Hosp China, China Mil Inst Chinese Mat Med, Beijing 100039, Peoples R China.
关键词：
S. aureus;Bile acid derivative;Microcalorimetry;MANOVA;PCA
摘要：
The effects of two bile acid derivatives, cholic acid (CA) and deoxycholic acid (DCA) on Staphylococcus aureus (S. aureus) growth were investigated and compared by microcalorimetry coupled with multiple analytical methods. The heat power (HP)-time curves of S. aureus growth affected by CA and DCA were studied by similarity analysis (SA), respectively. Then the quantitative thermo-kinetic parameters obtained from these curves were investigated by the multivariate analysis of variance (MANOVA) and principal component analysis (PCA). By analyzing the two main parameters, growth rate constant k(2) of the second exponential phase and the heat power P-2 of the second highest peak, together with the minimum inhibitory concentration (MIC) values of 10 mu g/mL for CA and 20 mu g/mL for DCA, it could be concluded that the antibacterial effect of CA was stronger than that of DCA. The existence of alpha-OH at C-7 position of steroid nucleus of bile acid derivatives enhanced the hydrophilicity of compound CA and its inhibitory effect on S. aureus. This study provides a useful method and idea to accurately evaluate the antibacterial effects of bile acid derivatives, which provides some references for screening out new antibacterial agents with high efficacy and low toxicity. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
