1
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Boyanova ST, Lloyd-Morris E, Corpe C, Rahman KM, Farag DB, Page LK, Wang H, Fleckney AL, Gatt A, Troakes C, Vizcay-Barrena G, Fleck R, Reeves SJ, Thomas SA. Interaction of amisulpride with GLUT1 at the blood-brain barrier. Relevance to Alzheimer's disease. PLoS One 2023; 18:e0286278. [PMID: 37874822 PMCID: PMC10597500 DOI: 10.1371/journal.pone.0286278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/27/2023] [Indexed: 10/26/2023] Open
Abstract
Blood-brain barrier (BBB) dysfunction may be involved in the increased sensitivity of Alzheimer's disease (AD) patients to antipsychotics, including amisulpride. Studies indicate that antipsychotics interact with facilitated glucose transporters (GLUT), including GLUT1, and that GLUT1 BBB expression decreases in AD. We tested the hypotheses that amisulpride (charge: +1) interacts with GLUT1, and that BBB transport of amisulpride is compromised in AD. GLUT1 substrates, GLUT1 inhibitors and GLUT-interacting antipsychotics were identified by literature review and their physicochemical characteristics summarised. Interactions between amisulpride and GLUT1 were studied using in silico approaches and the human cerebral endothelial cell line, hCMEC/D3. Brain distribution of [3H]amisulpride was determined using in situ perfusion in wild type (WT) and 5xFamilial AD (5xFAD) mice. With transmission electron microscopy (TEM) we investigated brain capillary degeneration in WT mice, 5xFAD mice and human samples. Western blots determined BBB transporter expression in mouse and human. Literature review revealed that, although D-glucose has no charge, charged molecules can interact with GLUT1. GLUT1 substrates are smaller (184.95±6.45g/mol) than inhibitors (325.50±14.40g/mol) and GLUT-interacting antipsychotics (369.38±16.04). Molecular docking showed beta-D-glucose (free energy binding: -15.39kcal/mol) and amisulpride (-29.04kcal/mol) interact with GLUT1. Amisulpride did not affect [14C]D-glucose hCMEC/D3 accumulation. [3H]amisulpride uptake into the brain (except supernatant) of 5xFAD mice compared to WT remained unchanged. TEM revealed brain capillary degeneration in human AD. There was no difference in GLUT1 or P-glycoprotein BBB expression between WT and 5xFAD mice. In contrast, caudate P-glycoprotein, but not GLUT1, expression was decreased in human AD capillaries versus controls. This study provides new details about the BBB transport of amisulpride, evidence that amisulpride interacts with GLUT1 and that BBB transporter expression is altered in AD. This suggests that antipsychotics could potentially exacerbate the cerebral hypometabolism in AD. Further research into the mechanism of amisulpride transport by GLUT1 is important for improving antipsychotics safety.
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Affiliation(s)
- Sevda T. Boyanova
- King’s College London, Institute of Pharmaceutical Science, London, United Kingdom
| | - Ethlyn Lloyd-Morris
- King’s College London, Institute of Pharmaceutical Science, London, United Kingdom
| | - Christopher Corpe
- King’s College London, Department of Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences and Medicine, London, United Kingdom
| | | | - Doaa B. Farag
- Faculty of Pharmacy, Misr International University, Cairo, Egypt
| | - Lee K. Page
- King’s College London, Institute of Pharmaceutical Science, London, United Kingdom
| | - Hao Wang
- King’s College London, Institute of Pharmaceutical Science, London, United Kingdom
| | - Alice L. Fleckney
- King’s College London, Institute of Pharmaceutical Science, London, United Kingdom
| | - Ariana Gatt
- King’s College London, Wolfson Centre for Age Related Disease, London, United Kingdom
| | - Claire Troakes
- King’s College London, London Neurodegenerative Diseases Brain Bank, IoPPN, London, United Kingdom
| | - Gema Vizcay-Barrena
- King’s College London, Centre for Ultrastructural Imaging, London, United Kingdom
| | - Roland Fleck
- King’s College London, Centre for Ultrastructural Imaging, London, United Kingdom
| | - Suzanne J. Reeves
- Faculty of Brain Sciences, University College London, London, United Kingdom
| | - Sarah A. Thomas
- King’s College London, Department of Physiology, London, United Kingdom
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2
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Liu S, Di Y, Li Q, Chen L, Ma Y, He X, Corpe C, Zhang X, Xu J, Wang J. Exosomal lncRNA LINC01268 promotes pancreatic cancer progression via the miR-217-KIF2A-PI3K/AKT axis. Genes Dis 2023; 10:1799-1801. [PMID: 37492701 PMCID: PMC10363640 DOI: 10.1016/j.gendis.2022.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/03/2022] [Accepted: 12/30/2022] [Indexed: 07/27/2023] Open
Affiliation(s)
- Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Yang Di
- Department of Pancreatic Surgery, Huashan Hospital, Fudan University, Shanghai 201508, China
| | - Qiuyue Li
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Litian Chen
- Department of Hepatobiliary Surgery, Shanghai Jiaotong University School of Medicine Xinhua Hospital, Shanghai 200025, China
| | - Yan Ma
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Xiaomeng He
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Christopher Corpe
- King's College London, London, Nutritional Science Department, Waterloo, London SE19NH, United Kingdom
| | - Xiaoyan Zhang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
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3
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Liu S, He X, Di Y, Li Q, Li F, Ma Y, Chen L, Gao Y, Xu J, Yang S, Xu L, Corpe C, Ling Y, Zhang X, Xu J, Yu W, Wang J. NamiRNA-enhancer network of miR-492 activates the NR2C1-TGF-β/Smad3 pathway to promote epithelial-mesenchymal transition of pancreatic cancer. Carcinogenesis 2023; 44:153-165. [PMID: 36591938 DOI: 10.1093/carcin/bgac102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 12/02/2022] [Accepted: 01/01/2023] [Indexed: 01/03/2023] Open
Abstract
Pancreatic cancer (PaCa) is one of the most fatal malignancies of the digestive system, and most patients are diagnosed at advanced stages due to the lack of specific and effective tumor-related biomarkers for the early detection of PaCa. miR-492 has been found to be upregulated in PaCa tumor tissue and may serve as a potential therapeutic target. However, the molecular mechanisms by which miR-492 promotes PaCa tumor growth and progression are unclear. In this study, we first found that miR-492 in enhancer loci activated neighboring genes (NR2C1/NDUFA12/TMCC3) and promoted PaCa cell proliferation, migration, and invasion in vitro. We also observed that miR-492-activating genes significantly enriched the TGF-β/Smad3 signaling pathway in PaCa to promote epithelial-mesenchymal transition (EMT) during tumorigenesis and development. Using CRISPR-Cas9 and ChIP assays, we further observed that miR-492 acted as an enhancer trigger, and that antagomiR-492 repressed PaCa tumorigenesis in vivo, decreased the expression levels of serum TGF-β, and suppressed the EMT process by downregulating the expression of NR2C1. Our results demonstrate that miR-492, as an enhancer trigger, facilitates PaCa progression via the NR2C1-TGF-β/Smad3 pathway.
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Affiliation(s)
- Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xiaomeng He
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Yang Di
- Department of Pancreatic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Qiuyue Li
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Feng Li
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Yan Ma
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Litian Chen
- Department of Hepatobiliary Surgery, Shanghai Jiaotong University School of Medicine Xinhua Hospital, Shanghai, China
| | - Yushi Gao
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China.,School of Life Sciences, Hubei University, Wuhan, 430062, China
| | - Jingjing Xu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Shuai Yang
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Li Xu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Christopher Corpe
- King's College London, London, Nutritional Science Department, 150 Stamford Street, Waterloo, London, SE19NH, United Kingdom
| | - Yun Ling
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xiaoyan Zhang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Wenqiang Yu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China.,Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
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4
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Ma Y, He X, Di Y, Liu S, Zhan Q, Bai Z, Qiu T, Corpe C, Wang J. Identification of prognostic immune-related lncRNAs in pancreatic cancer. Front Immunol 2022; 13:1005695. [PMID: 36420274 PMCID: PMC9676238 DOI: 10.3389/fimmu.2022.1005695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/21/2022] [Indexed: 08/29/2023] Open
Abstract
Long noncoding RNAs (lncRNAs) play a critical role in the immune regulation and tumor microenvironment of pancreatic cancer (PaCa). To construct a novel immune-related prognostic risk model for PaCa and evaluate the prognostic prediction of lncRNAs, essential immune-related lncRNAs (IRlncRNAs) were identified by Pearson correlation analysis of differentially expressed immune-related genes (IRGs) and IRlncRNAs in PaCa from The Cancer Genome Atlas (TCGA) and GTEx databases. Least absolute shrinkage and selection operator (LASSO) regression was also applied to construct a prognostic risk model of IRlncRNAs, and gene set enrichment analysis (GSEA) was further applied for functional annotation for these IRlncRNAs. A total of 148 IRlncRNAs were identified in PaCa to construct a prognostic risk model. Among them, lncRNA LINC02325, FNDC1-AS1, and ZEB2-AS1 were significantly upregulated in 69 pairs of PaCa tissues by qRT-PCR. ROC analyses showed that LINC02325 (AUC = 0.80), FNDC1-AS1 (AUC = 0.76), and ZEB2-AS1 (AUC = 0.75) had a good predictive effect on 5-year survival prognosis. We demonstrated that high expression levels of ZEB2-AS1 and LINC02325 were not only positively associated with tumor size and CA199, but elevated levels of ZEB2-AS1 and FNDC1-AS1 were also positively correlated with tumor stage. GSEA further revealed that immune-related pathways were mainly enriched in the high-risk groups. Several immune-related algorithms demonstrated that four IRlncRNAs were related to immune infiltration, immune checkpoints, and immune-related functions. Thus, the prognostic risk model based on IRlncRNAs in Paca indicates that the four IRlncRNA signatures may serve as predictors of survival and potential predictive biomarkers of the pancreatic tumor immune response.
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Affiliation(s)
- Yan Ma
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xiaomeng He
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Yang Di
- Department of Pancreatic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Qilin Zhan
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Zhihui Bai
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Tianyi Qiu
- Institute of Clinical Science, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Christopher Corpe
- Nutritional Science Department, King’s College London, London, United Kingdom
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
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5
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Bao J, Ye J, Xu J, Liu S, Wang L, Li Z, Li Q, Liu F, He X, Zou H, Feng Y, Corpe C, Zhang X, Xu J, Zhu T, Wang J. Comprehensive RNA-seq reveals molecular changes in kidney malignancy among people living with HIV. Molecular Therapy - Nucleic Acids 2022; 29:91-101. [PMID: 35795483 PMCID: PMC9240952 DOI: 10.1016/j.omtn.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 06/05/2022] [Indexed: 11/30/2022]
Abstract
To heighten the awareness of kidney malignancy in patients with HIV infection to facilitate the early diagnosis of kidney cancer, the differentially expressed mRNAs were analyzed in this malignant tumor using RNA sequencing. We identified 2,962 protein-coding transcripts in HIV-associated kidney cancer. KISS1R, CAIX, and NPTX2 mRNA expression levels were specifically increased in HIV-associated kidney cancer while UMOD and TMEM213 mRNA were decreased in most cases based on real-time PCR analyses. These findings were similar to those noted for the general population with renal cell carcinoma. Immunohistochemical staining analysis also showed that a total of 18 malignant kidney cases among the people living with HIV (PLWH) exhibited positive staining for KISS1R and CAIX. Pathway analysis of the differentially expressed mRNAs in HIV-associated kidney cancer revealed that several key pathways were involved, including vascular endothelial growth factor-activated receptor activity, IgG binding, and lipopolysaccharide receptor activity. Altogether, our findings reveal the identified molecular changes in kidney malignancy, which may offer a helpful explanation for cancer progression and open up new therapeutic avenues that may decrease mortality after a cancer diagnosis among PLWH.
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Ma Y, Di Y, Li Q, Zhan Q, He X, Liu S, Zou H, Corpe C, Chen L, Wang J. LncRNAs as epigenetic regulators of epithelial to mesenchymal transition in pancreatic cancer. Discov Oncol 2022; 13:61. [PMID: 35819532 PMCID: PMC9276894 DOI: 10.1007/s12672-022-00522-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/01/2022] [Indexed: 11/04/2022] Open
Abstract
Pancreatic cancer is the leading cause of cancer-related mortality because of tumor metastasis. Activation of the epithelial-to-mesenchymal transition (EMT) pathway has been confirmed to be an important driver of pancreatic cancer progression from initiation to metastasis. Long noncoding RNAs (lncRNAs) have been reported to exert essential physiological functions in pancreatic cancer progression by regulating the EMT program. In this review, we have summarized the role of EMT-related lncRNAs in human pancreatic cancer and the potential molecular mechanisms by which lncRNAs can be vital epigenetic regulators of epithelial to mesenchymal transition. Specifically, EMT-activating transcription factors (EMT-TFs) regulate EMT via TGF-β/Smad, Wnt/β-catenin, and JAK/STAT pathways. In addition, the interaction between lncRNAs and HIF-1α and m6A RNA methylation also have an impact on tumor metastasis and EMT in pancreatic cancer. This review will provide insights into lncRNAs as promising biomarkers for tumor metastasis and potential therapeutic strategies for pancreatic cancer.
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Affiliation(s)
- Yan Ma
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China
| | - Yang Di
- Department of Pancreatic Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Qiuyue Li
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China
| | - Qilin Zhan
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China
| | - Xiaomeng He
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China
| | - Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China
| | - Heng Zou
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China
| | - Christopher Corpe
- King's College London, Nutritional Science Department, 150 Stamford Street, Waterloo, London, SE19NH, UK
| | - Litian Chen
- Department of Hepatobiliary Surgery, Shanghai Jiaotong University School of Medicine Xinhua Hospital, Kongjiang Road 1665, Shanghai, China.
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508, People's Republic of China.
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7
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Wang J, Zou H, Corpe C. An observed association between angiotensin-converting enzyme 2 polymorphisms and COVID-19 severity in China. J Infect 2022; 84:e21-e22. [PMID: 34728265 PMCID: PMC8556693 DOI: 10.1016/j.jinf.2021.10.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 10/26/2021] [Indexed: 12/25/2022]
Affiliation(s)
- Jin Wang
- Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Shanghai, China.
| | - Heng Zou
- Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Shanghai, China
| | - Christopher Corpe
- Nutritional Science Department, King's College London, 150 Stamford Street, Waterloo, London SE19NH, United Kingdom
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8
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Liu S, Li Q, Chu X, Zeng M, Liu M, He X, Zou H, Zheng J, Corpe C, Zhang X, Xu J, Wang J. Monitoring Coronavirus Disease 2019: A Review of Available Diagnostic Tools. Front Public Health 2021; 9:672215. [PMID: 34164371 PMCID: PMC8215441 DOI: 10.3389/fpubh.2021.672215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/23/2021] [Indexed: 01/08/2023] Open
Abstract
Coronavirus disease 2019 (COVID-19) pneumonia is caused by the virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has rapidly become a global public health concern. As the new type of betacoronavirus, SARS-CoV-2 can spread across species and between populations and has a greater risk of transmission than other coronaviruses. To control the spread of SARS-CoV-2, it is vital to have a rapid and effective means of diagnosing asymptomatic SARS-CoV-2-positive individuals and patients with COVID-19, an early isolation protocol for infected individuals, and effective treatments for patients with COVID-19 pneumonia. In this review, we will summarize the novel diagnostic tools that are currently available for coronavirus, including imaging examinations and laboratory medicine by next-generation sequencing (NGS), real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) analysis, immunoassay for COVID-19, cytokine and T cell immunoassays, biochemistry and microbiology laboratory parameters in the blood of the patients with COVID-19, and a field-effect transistor-based biosensor of COVID-19. Specifically, we will discuss the effective detection rate and assay time for the rRT-PCR analysis of SARS-CoV-2 and the sensitivity and specificity of different antibody detection methods, such as colloidal gold and ELISA using specimen sources obtained from the respiratory tract, peripheral serum or plasma, and other bodily fluids. Such diagnostics will help scientists and clinicians develop appropriate strategies to combat COVID-19.
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Affiliation(s)
- Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Qiuyue Li
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xuntao Chu
- Zhuhai Livzon Diagnostics Inc., Guangdong, China
| | - Minxia Zeng
- Zhuhai Livzon Diagnostics Inc., Guangdong, China
| | - Mingbin Liu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
- School of Pharmacy, Gannan Medical University, Jiangxi, China
| | - Xiaomeng He
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Heng Zou
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Jianghua Zheng
- Department of Laboratory Medicine, Zhoupu Hospital Affiliated to Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Christopher Corpe
- Nutritional Science Department, King's College London, London, United Kingdom
| | - Xiaoyan Zhang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
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9
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Liu S, Li Q, Ma Y, Corpe C, Wang J. Circular RNAs as novel potential biomarkers for pancreatic cancer. J Cancer 2021; 12:4604-4615. [PMID: 34149924 PMCID: PMC8210554 DOI: 10.7150/jca.58640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/19/2021] [Indexed: 12/13/2022] Open
Abstract
Pancreatic cancer (PaCa) is the fourth leading cause of cancer-related deaths in the United States, and the vast majority of these malignancies are pancreatic ductal adenocarcinomas (PDAC), but there is still a lack of early detection biomarkers for PaCa. Unlike linear RNAs, circRNAs form covalently closed continuous loops and can act as mammalian gene regulators. They may be diagnostic or predictive biomarkers for some tumors, also be novel potential therapeutic targets in different diseases. This review focuses on (1) the biogenesis of circRNAs, RNA binding proteins (RBPs) and complementary sequences of circRNAs; (2) the characteristics of circRNAs which allow them to interact with miRNAs; (3) the roles of circRNAs playing in the regulation of gene expression, cell behavior and cancer, and their potential role as novel biomarkers and therapeutic targets in pancreatic cancer.
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Affiliation(s)
- Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai 201508, China
| | - Qiuyue Li
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai 201508, China
| | - Yan Ma
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai 201508, China
| | - Christopher Corpe
- King's College London, London, Nutritional Science Department, 150 Stamford street, waterloo, London, SE19NH, United Kingdom
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai 201508, China
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10
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Jiang S, Li Q, Li C, Liu S, He X, Wang T, Li H, Corpe C, Zhang X, Xu J, Wang J. Mathematical models for devising the optimal SARS-CoV-2 strategy for eradication in China, South Korea, and Italy. J Transl Med 2020; 18:345. [PMID: 32891155 PMCID: PMC7474336 DOI: 10.1186/s12967-020-02513-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spreads rapidly and has attracted worldwide attention. METHODS To improve the forecast accuracy and investigate the spread of SARS-CoV-2, we constructed four mathematical models to numerically estimate the spread of SARS-CoV-2 and the efficacy of eradication strategies. RESULTS Using the Susceptible-Exposed-Infected-Removed (SEIR) model, and including measures such as city closures and extended leave policies implemented by the Chinese government that effectively reduced the β value, we estimated that the β value and basic transmission number, R0, of SARS-CoV-2 was 0.476/6.66 in Wuhan, 0.359/5.03 in Korea, and 0.400/5.60 in Italy. Considering medicine and vaccines, an advanced model demonstrated that the emergence of vaccines would greatly slow the spread of the virus. Our model predicted that 100,000 people would become infected assuming that the isolation rate α in Wuhan was 0.30. If quarantine measures were taken from March 10, 2020, and the quarantine rate of α was also 0.3, then the final number of infected people was predicted to be 11,426 in South Korea and 147,142 in Italy. CONCLUSIONS Our mathematical models indicate that SARS-CoV-2 eradication depends on systematic planning, effective hospital isolation, and SARS-CoV-2 vaccination, and some measures including city closures and leave policies should be implemented to ensure SARS-CoV-2 eradication.
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Affiliation(s)
- Shuo Jiang
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Qiuyue Li
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Chaoqun Li
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Shanshan Liu
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Xiaomeng He
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Tao Wang
- Wuhan Academy of Social Science, Wuhan, Hubei China
| | - Hua Li
- State Key Laboratory for Oncogenes and Bio-ID Center, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Christopher Corpe
- King’s College London, Nutritional Science Department, 150 Stamford Street, Waterloo, SE19NH London, UK
| | - Xiaoyan Zhang
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Jianqing Xu
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
| | - Jin Wang
- Shanghai Public Health Clinical Center, Fudan University, 2901 Caolang Road, Jinshan District, Shanghai, 201508 People’s Republic of China
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11
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Zhang X, Liu T, Li Z, Feng Y, Corpe C, Liu S, Zhang J, He X, Liu F, Xu L, Shen L, Li S, Xia Q, Peng X, Zhou X, Chen W, Zhang X, Xu J, Wang J. Hepatomas are exquisitely sensitive to pharmacologic ascorbate (P-AscH -). Am J Cancer Res 2019; 9:8109-8126. [PMID: 31754384 PMCID: PMC6857065 DOI: 10.7150/thno.35378] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 09/08/2019] [Indexed: 02/06/2023] Open
Abstract
Rationale: Ascorbate is an essential micronutrient known for redox functions at normal physiologic concentrations. In recent decades, pharmacological ascorbate has been found to selectively kill tumour cells. However, the dosing frequency of pharmacologic ascorbate in humans has not yet been defined. Methods: We determined that among five hepatic cell lines, Huh-7 cells were the most sensitive to ascorbate. The effects of high-dose ascorbate on hepatoma were therefore assessed using Huh-7 cells and xenograft tumour mouse model. Results: In Huh-7 cells, ascorbate induced a significant increase in the percentage of cells in the G0/G1 phase, apoptosis and intracellular levels of ROS. High doses of ascorbate (4.0 pmol cell-1), but not low doses of ascorbate (1.0 pmol cell-1), also served as a pro-drug that killed hepatoma cells by altering mitochondrial respiration. Furthermore, in a Huh-7 cell xenograft tumour mouse model, intraperitoneal injection of ascorbate (4.0 g/kg/3 days) but not a lower dose of ascorbate (2.0 g/kg/3 days) significantly inhibited tumour growth. Gene array analysis of HCC tumour tissue from xenograft mice given IP ascorbate (4.0 g/kg/3 days) identified changes in the transcript levels of 192 genes/ncRNAs involved in insulin receptor signalling, metabolism and mitochondrial respiration. Consistent with the array data, gene expression levels of AGER, DGKK, ASB2, TCP10L2, Lnc-ALCAM-3, and Lnc-TGFBR2-1 were increased 2.05-11.35 fold in HCC tumour tissue samples from mice treated with high-dose ascorbate, and IHC staining analysis also verified that AGER/RAGE and DGKK proteins were up-regulated, which implied that AGER/RAGE and DGKK activation might be related to oxidative stress, leading to hepatoma cell death. Conclusions: Our studies identified multiple mechanisms are responsible for the anti-tumour activity of ascorbate and suggest high doses of ascorbate with less frequency will act as a novel therapeutic agent for liver cancer in vivo.
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Wang J, Wu F, Corpe C. Editorial: Vitamin C in Cancer and Infectious Diseases: Physiological, Biochemical and Therapeutic Interventions. Front Physiol 2019; 10:734. [PMID: 31275158 PMCID: PMC6591432 DOI: 10.3389/fphys.2019.00734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 05/27/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jin Wang
- Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Fan Wu
- Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Christopher Corpe
- Nutritional Science Department, King's College London, London, United Kingdom
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O'Brien P, Hewett R, Corpe C. Sugar sensor genes in the murine gastrointestinal tract display a cephalocaudal axis of expression and a diurnal rhythm. Physiol Genomics 2018; 50:448-458. [PMID: 29625018 DOI: 10.1152/physiolgenomics.00139.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Distributed along the length of the gastrointestinal (GI) tract are nutrient sensing cells that release numerous signaling peptides influencing GI function, nutrient homeostasis and energy balance. Recent studies have shown a diurnal rhythm in GI nutrient sensing, but the mechanisms responsible for rhythmicity are poorly understood. In this report we studied murine GI sugar sensor gene and protein expression levels in the morning (7 AM) and evening (7 PM). Sweet taste receptor ( tas1r2/tas1r3/gnat3/gnat1) sugar transporter ( slc5a1, slc2a2, slc2a5) and putative sugar sensor ( slc5a4a and slc5a4b) gene expression levels were highest in tongue and proximal and distal small intestine, respectively. Clock gene ( cry2/arntl) activity was detected in all regions studied. Slc5a4a and slc5a4b gene expression showed clear diurnal rhythmicity in the small intestine and stomach, respectively, although no rhythmicity was detected in SGLT3 protein expression. Tas1r2, tas1r3, gnat1, and gcg displayed a limited rhythm in gene expression in proximal small intestine. Microarray analysis revealed a diurnal rhythm in gut peptide gene expression in tongue (7 AM vs. 7 PM) and in silico promoter analysis indicated intestinal sugar sensors and transporters possessed the canonical E box elements necessary for clock gene control over gene transcription. In this report we present evidence of a diurnal rhythm in genes that are responsible for intestinal nutrient sensing that is most likely controlled by clock gene activity. Disturbances in clock gene/nutrient sensing interactions may be important in the development of diet-related diseases, such as obesity and diabetes.
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Affiliation(s)
- Patrick O'Brien
- Department of Nutritional Sciences, School of Medicine, King's College London , London , United Kingdom
| | - Rhys Hewett
- Department of Nutritional Sciences, School of Medicine, King's College London , London , United Kingdom
| | - Christopher Corpe
- Department of Nutritional Sciences, School of Medicine, King's College London , London , United Kingdom
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Mehat K, Corpe C. Artificial sweeteners and dietary disaccharides promote the release of glucagon‐like peptide‐1 in GLUTag cells, an in vitro model of the enteroendocrine cell. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.767.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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15
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Carvalho S, Molina-López J, Parsons D, Corpe C, Maret W, Hogstrand C. Differential cytolocation and functional assays of the two major human SLC30A8 (ZnT8) isoforms. J Trace Elem Med Biol 2017; 44:116-124. [PMID: 28965566 DOI: 10.1016/j.jtemb.2017.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 06/02/2017] [Accepted: 06/06/2017] [Indexed: 11/22/2022]
Abstract
The non-synonymous single nucleotide polymorphism (SNP) rs13266634 in human zinc transporter 8, ZnT8 (SLC30A8), leads to a R325 variant, which is associated with an increased risk of developing Type 2 Diabetes (T2D). Although the molecular details remain unknown, the mutation is thought to alter the kinetics of zinc transport into insulin granules in pancreatic β-cells. Nevertheless, analysis of ZnT8 sequences from several animals shows that the amino acid at position 325 is poorly conserved. Apart from this particular SNP, human ZnT8 also has two isoforms (splice variants) that differ in length regarding a 49 amino acid N-terminal extension. When expressed in human embryonic kidney (HEK293) cells, the long isoform was present in the plasma membrane in addition to internal membranes, whereas the short isoform was localized mostly to internal membranes. Our observation that human ZnT8 variants and isoforms expressed in Xenopus laevis oocytes are all localized at the cell surface allowed us to develop a zinc transport assay using the radioactive isotope 65Zn. We found no detectable differences in zinc transport between W and R variants and no statistically significant differences between long and short isoforms of the W325 variant. Our findings of differential cytolocation of ZnT8 isoforms could be relevant for β-cell zinc metabolism in health and disease.
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Affiliation(s)
- Sandra Carvalho
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Jorge Molina-López
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK; Department of Physiology, Institute of Nutrition and Food Technology "José Mataix", University of Granada, Spain
| | - Douglas Parsons
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Christopher Corpe
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Wolfgang Maret
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK.
| | - Christer Hogstrand
- Diabetes and Nutritional Sciences Division, Faculty of Life Sciences and Medicine, King's College London, London, UK
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Eck PK, Corpe C, Levine MA. Temporo-spacial microanatomical distribution of the murine sodium-dependent ascorbic acid transporters Slc23a1 and Slc23a2 in the kidney throughout development. Biochem Cell Biol 2016; 95:421-427. [PMID: 28177761 DOI: 10.1139/bcb-2015-0090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The two membrane transporters Slc23a1 and Slc23a2 mediate ascorbic acid uptake into cells. We recently determined the key role of Slc23a1 in renal re-absorption of ascorbic acid in a knockout mouse model. However, the renal spatial and temporal expression patterns of murine Slc23a1 and Slc23a2 are not defined. This study utilizes database evidence combined with experimental confirmation via in-situ hybridization to define the spatial and temporal expression of Slc23a1 in the murine kidney. Slc23a1 is expressed in the early proximal tubule, but not in its precursors during embryonic development, and exclusive proximal tubular expression persists throughout the animal's lifetime. In contrast, Slc23a2 is uniformly expressed in metabolic cell types such as stromal cells. The expression patterns appear to be conserved from rodent lineages to humans.
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Affiliation(s)
- Peter K Eck
- a University of Manitoba, Department of Human Nutritional Sciences, W569 Duff Roblin Building, 190 Dysart Road, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,b Molecular and Clinical Nutrition Section, Building 10, Room 4D52 MSC 1372, National Institutes of Health, Bethesda, MD 20892-1372, USA
| | - Christopher Corpe
- b Molecular and Clinical Nutrition Section, Building 10, Room 4D52 MSC 1372, National Institutes of Health, Bethesda, MD 20892-1372, USA.,c Department of Nutrition and Dietetics, Diabetes & Nutritional Sciences Division, School of Medicine, King's College London, Room 3.114 Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK
| | - Mark A Levine
- b Molecular and Clinical Nutrition Section, Building 10, Room 4D52 MSC 1372, National Institutes of Health, Bethesda, MD 20892-1372, USA
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Eck P, Erichsen HC, Taylor JG, Corpe C, Chanock SJ, Levine M. Genomic and functional analysis of the sodium-dependent vitamin C transporter SLC23A1-SVCT1. Genes Nutr 2011; 2:143-5. [PMID: 18850166 DOI: 10.1007/s12263-007-0040-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Peter Eck
- Molecular and Clinical Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA,
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18
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Corpe C, Tu H, Wang J, Eck P, Wang Y, Schnermann J, Faulhaber‐Walter R, Nussbaum R, Levine M. SVCT1 (Slc23a1) knockout mice: Slc23a1 as the vitamin C kidney reabsorptive transporter. FASEB J 2007. [DOI: 10.1096/fasebj.21.6.lb111] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | | | | | - Robert Nussbaum
- Medicine/GeneticsUniversity of California ‐ San FranciscoBox 0794, Core Campus, HSE 901E, University of California, San FranciscoSan FranciscoCA94143
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Zhang L, Nair A, Krady K, Corpe C, Bonneau RH, Simpson IA, Vannucci SJ. Estrogen stimulates microglia and brain recovery from hypoxia-ischemia in normoglycemic but not diabetic female mice. J Clin Invest 2004. [PMID: 14702112 DOI: 10.1172/jci200418336] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Diabetic hyperglycemia increases ischemic brain damage in experimental animals and humans. The mechanisms are unclear but may involve enhanced apoptosis in penumbral regions. Estrogen is an established neuroprotectant in experimental stroke. Our previous study demonstrated that female diabetic db/db mice suffered less damage following cerebral hypoxia-ischemia (H/I) than male db/db mice. Here we investigated the effects of diabetes and estrogen apoptotic gene expression following H/I. Female db/db and nondiabetic (+/?) mice were ovariectomized (OVX) and treated with estrogen or vehicle prior to H/I; brains were analyzed for damage and bcl-2 family gene expression. OVX increased ischemic damage in +/? mice; estrogen reduced tissue injury and enhanced antiapoptotic gene expression (bcl-2 and bfl-1). db/db mice demonstrated more damage, without increased bcl-2 mRNA; bfl-1 expression appeared at 48 hours of recovery associated with infarction. To our knowledge, this is the first description of bfl-1 in the brain with localization to microglia and macrophages. Early induction of bfl-1 expression in +/? mouse brain was associated with microglia; delayed bfl-1 expression in diabetic brain was in macrophages bordering the infarct. Furthermore, estrogen replacement stimulated early postischemic expression of bcl-2 and bfl-1 and reduced damage in normoglycemic animals but failed to protect the diabetic brain.
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Affiliation(s)
- Liqun Zhang
- Department of Pediatrics, Morgan Stanley Children's Hospital of New York, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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Zhang L, Nair A, Krady K, Corpe C, Bonneau RH, Simpson IA, Vannucci SJ. Estrogen stimulates microglia and brain recovery from hypoxia-ischemia in normoglycemic but not diabetic female mice. J Clin Invest 2004; 113:85-95. [PMID: 14702112 PMCID: PMC300764 DOI: 10.1172/jci18336] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2003] [Accepted: 11/04/2003] [Indexed: 12/25/2022] Open
Abstract
Diabetic hyperglycemia increases ischemic brain damage in experimental animals and humans. The mechanisms are unclear but may involve enhanced apoptosis in penumbral regions. Estrogen is an established neuroprotectant in experimental stroke. Our previous study demonstrated that female diabetic db/db mice suffered less damage following cerebral hypoxia-ischemia (H/I) than male db/db mice. Here we investigated the effects of diabetes and estrogen apoptotic gene expression following H/I. Female db/db and nondiabetic (+/?) mice were ovariectomized (OVX) and treated with estrogen or vehicle prior to H/I; brains were analyzed for damage and bcl-2 family gene expression. OVX increased ischemic damage in +/? mice; estrogen reduced tissue injury and enhanced antiapoptotic gene expression (bcl-2 and bfl-1). db/db mice demonstrated more damage, without increased bcl-2 mRNA; bfl-1 expression appeared at 48 hours of recovery associated with infarction. To our knowledge, this is the first description of bfl-1 in the brain with localization to microglia and macrophages. Early induction of bfl-1 expression in +/? mouse brain was associated with microglia; delayed bfl-1 expression in diabetic brain was in macrophages bordering the infarct. Furthermore, estrogen replacement stimulated early postischemic expression of bcl-2 and bfl-1 and reduced damage in normoglycemic animals but failed to protect the diabetic brain.
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Affiliation(s)
- Liqun Zhang
- Department of Pediatrics, Morgan Stanley Children's Hospital of New York, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA
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Padayatty SJ, Katz A, Wang Y, Eck P, Kwon O, Lee JH, Chen S, Corpe C, Dutta A, Dutta SK, Levine M. Vitamin C as an antioxidant: evaluation of its role in disease prevention. J Am Coll Nutr 2003; 22:18-35. [PMID: 12569111 DOI: 10.1080/07315724.2003.10719272] [Citation(s) in RCA: 924] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vitamin C in humans must be ingested for survival. Vitamin C is an electron donor, and this property accounts for all its known functions. As an electron donor, vitamin C is a potent water-soluble antioxidant in humans. Antioxidant effects of vitamin C have been demonstrated in many experiments in vitro. Human diseases such as atherosclerosis and cancer might occur in part from oxidant damage to tissues. Oxidation of lipids, proteins and DNA results in specific oxidation products that can be measured in the laboratory. While these biomarkers of oxidation have been measured in humans, such assays have not yet been validated or standardized, and the relationship of oxidant markers to human disease conditions is not clear. Epidemiological studies show that diets high in fruits and vegetables are associated with lower risk of cardiovascular disease, stroke and cancer, and with increased longevity. Whether these protective effects are directly attributable to vitamin C is not known. Intervention studies with vitamin C have shown no change in markers of oxidation or clinical benefit. Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations. Hence, optimal dosing is critical to intervention studies using vitamin C. Ideally, future studies of antioxidant actions of vitamin C should target selected patient groups. These groups should be known to have increased oxidative damage as assessed by a reliable biomarker or should have high morbidity and mortality due to diseases thought to be caused or exacerbated by oxidant damage.
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Affiliation(s)
- Sebastian J Padayatty
- Molecular and Clinical Nutrition Section, Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Corpe C, Sreenan S, Burant C. Effects of type-2 diabetes and troglitazone on the expression patterns of small intestinal sugar transporters and PPAR-gamma in the Zucker diabetic fatty rat. Digestion 2002; 63:116-23. [PMID: 11244250 DOI: 10.1159/000051879] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND/AIMS We have used the Zucker diabetic fatty (ZDF) rat to study the effects of type-2 diabetes and troglitazone on the small intestinal mucosal mass, sugar transporters and the peroxisomal proliferator-activated receptor, PPAR-gamma. METHODS Age-matched ZDF and lean control (ZLC) rats were fed a standard chow or a troglitazone-enriched diet for 6 weeks. The mucosa of the small intestines were then extracted, weighed, and SGLT1, GLUT2, GLUT5 and PPAR-gamma mRNA expression levels assessed by Northern blotting. In the same animal groups, Western blotting and immunohistochemistry were used to study SGLT1, GLUT2 and GLUT5 protein expression levels and targeting. RESULTS The ZDF rat small intestinal mucosal mass was 60% greater than the ZLC rat. However, the expression levels of SGLT1, GLUT2, GLUT5 mRNA and protein, and PPAR-gamma mRNA in the ZDF and ZLC rats were the same. In addition, the targeting of brush-border GLUT5 and basolateral GLUT2 protein in the ZDF and ZLC rats were the same. Troglitazone treatment reduced SGLT1 mRNA and protein expression levels by 50% in ZDF and ZLC rats, but had no effect on mucosal mass or the expression levels of GLUT2 mRNA and protein, GLUT5 mRNA, and PPAR-gamma mRNA. The expression levels of GLUT5 protein in troglitazone-treated ZLC rats were unchanged when compared to untreated ZLC rats. However, GLUT5 protein expression levels in the troglitazone-treated ZDF rats were 50% below the untreated ZDF rats. CONCLUSIONS Hyperphagia and insulin are the chronic regulators of small intestinal mucosal mass and sugar transporter expression patterns, respectively. Furthermore, troglitazone suppresses SGLT1 expression at the transcriptional level and GLUT5 at the post-translational level, independent of changes in glycemia or PPAR-gamma gene expression.
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Affiliation(s)
- C Corpe
- Department of Medicine, University of Chicago, Ill., USA.
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