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Li X, Liu M, Xing Y, Niu Y, Liu TH, Sun JL, Liu Y, Hemba-Waduge RUS, Ji JY. Distinct effects of CDK8 module subunits on cellular growth and proliferation in Drosophila. bioRxiv 2024:2024.04.30.591924. [PMID: 38746212 PMCID: PMC11092604 DOI: 10.1101/2024.04.30.591924] [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] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The Mediator complex, composed of about 30 conserved subunits, plays a pivotal role in facilitating RNA polymerase II-dependent transcription in eukaryotes. Within this complex, the CDK8 kinase module (CKM), comprising Med12, Med13, CDK8, and CycC (Cyclin C), serves as a dissociable subcomplex that modulates the activity of the small Mediator complex. Genetic studies in Drosophila have revealed distinct phenotypes of CDK8-CycC and Med12-Med13 mutations, yet the underlying mechanism has remained unknown. Here, using Drosophila as a model organism, we show that depleting CDK8-CycC enhances E2F1 target gene expression and promotes cell-cycle progression. Conversely, depletion of Med12-Med13 affects the expression of ribosomal protein genes and fibrillarin, indicating a more severe reduction in ribosome biogenesis and cellular growth compared to the loss of CDK8-CycC. Moreover, we found that the stability of CDK8 and CycC relies on Med12 and Med13, with a mutually interdependent relationship between Med12 and Med13. Furthermore, CycC stability depends on the other three CKM subunits. These findings reveal distinct roles for CKM subunits in vivo , with Med12-Med13 disruption exerting a more pronounced impact on ribosome biogenesis and cellular growth compared to the loss of CDK8-CycC. Significance The CDK8 kinase module (CKM), comprising CDK8, CycC, Med12, and Med13, is essential in the Mediator complex for RNA polymerase II-dependent transcription in eukaryotes. While expected to function jointly, CKM subunit mutations result in distinct phenotypes in Drosophila . This study investigates the mechanisms driving these differing effects. Our analysis reveals the role of Med12-Med13 pair in regulating ribosomal biogenesis and cellular growth, contrasting with the involvement of CDK8-CycC in E2F1-dependent cell-cycle progression. Additionally, an asymmetric interdependence in the stability of CDK8-CycC and Med12-Med13 was observed. CKM mutations or overexpression are associated with cancers and cardiovascular diseases. Our findings underscore the distinct impacts of CKM mutations on cellular growth and proliferation, advancing our understanding of their diverse consequences in vivo .
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Liu M, Xie XJ, Li X, Ren X, Sun J, Lin Z, Hemba-Waduge RUS, Ji JY. Transcriptional coupling of telomeric retrotransposons with the cell cycle. bioRxiv 2023:2023.09.30.560321. [PMID: 37808851 PMCID: PMC10557779 DOI: 10.1101/2023.09.30.560321] [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] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Instead of employing telomerases to safeguard chromosome ends, dipteran species maintain their telomeres by transposition of telomeric-specific retrotransposons (TRs): in Drosophila , these are HeT-A , TART , and TAHRE . Previous studies have shown how these TRs create tandem repeats at chromosome ends, but the exact mechanism controlling TR transcription has remained unclear. Here we report the identification of multiple subunits of the transcription cofactor Mediator complex and transcriptional factors Scalloped (Sd, the TEAD homolog in flies) and E2F1-Dp as novel regulators of TR transcription and telomere length in Drosophila . Depletion of multiple Mediator subunits, Dp, or Sd increased TR expression and telomere length, while over-expressing E2F1-Dp or knocking down the E2F1 regulator Rbf1 (Retinoblastoma-family protein 1) stimulated TR transcription, with Mediator and Sd affecting TR expression through E2F1-Dp. The CUT&RUN analysis revealed direct binding of CDK8, Dp, and Sd to telomeric repeats. These findings highlight the essential role of the Mediator complex in maintaining telomere homeostasis by regulating TR transcription through E2F1-Dp and Sd, revealing the intricate coupling of TR transcription with the host cell-cycle machinery, thereby ensuring chromosome end protection and genomic stability during cell division.
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Li X, Zhang M, Liu M, Liu TH, Hemba-Waduge RUS, Ji JY. Cdk8 attenuates lipogenesis by inhibiting SREBP-dependent transcription in Drosophila. Dis Model Mech 2022; 15:dmm049650. [PMID: 36305265 PMCID: PMC9702540 DOI: 10.1242/dmm.049650] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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: 05/12/2022] [Accepted: 10/14/2022] [Indexed: 10/10/2023] Open
Abstract
Fine-tuning of lipogenic gene expression is important for the maintenance of long-term homeostasis of intracellular lipids. The SREBP family of transcription factors are master regulators that control the transcription of lipogenic and cholesterogenic genes, but the mechanisms modulating SREBP-dependent transcription are still not fully understood. We previously reported that CDK8, a subunit of the transcription co-factor Mediator complex, phosphorylates SREBP at a conserved threonine residue. Here, using Drosophila as a model system, we observed that the phosphodeficient SREBP proteins (SREBP-Thr390Ala) were more stable and more potent in stimulating the expression of lipogenic genes and promoting lipogenesis in vivo than wild-type SREBP. In addition, starvation blocked the effects of wild-type SREBP-induced lipogenic gene transcription, whereas phosphodeficient SREBP was resistant to this effect. Furthermore, our biochemical analyses identified six highly conserved amino acid residues in the N-terminus disordered region of SREBP that are required for its interactions with both Cdk8 and the MED15 subunit of the small Mediator complex. These results support that the concerted actions of Cdk8 and MED15 are essential for the tight regulation of SREBP-dependent transcription. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Xiao Li
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Meng Zhang
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Louisiana Cancer Research Center, 1700 Tulane Avenue, New Orleans, LA 70112, USA
| | - Mengmeng Liu
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Louisiana Cancer Research Center, 1700 Tulane Avenue, New Orleans, LA 70112, USA
| | - Tzu-Hao Liu
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Louisiana Cancer Research Center, 1700 Tulane Avenue, New Orleans, LA 70112, USA
| | - Rajitha-Udakara-Sampath Hemba-Waduge
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Louisiana Cancer Research Center, 1700 Tulane Avenue, New Orleans, LA 70112, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Louisiana Cancer Research Center, 1700 Tulane Avenue, New Orleans, LA 70112, USA
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Wang QY, Zhang HL, Ren Z, Liu YB, Ji JY, Huang J. Transcriptome Sequencing Analysis of Chrysomyia Megacephala Pupae in Different Growing Periods. Fa Yi Xue Za Zhi 2021; 37:318-324. [PMID: 34379899 DOI: 10.12116/j.issn.1004-5619.2020.401214] [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] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Indexed: 11/30/2022]
Abstract
Abstract Objective To study the growth regulation, environmental adaption and epigenetic regulation of Chrysomyia Megacephala pupae, in order to obtain the transcriptome data of Chrysomyia Megacephala in different growing periods, and lay the foundation for forensic application. Methods The Chrysomyia Megacephala was cultivated and after pupation, 3 pupae were collected every 24 h from pupation to emergence, and stored at -80 ℃ for later use. High-throughput sequencing was performed by Illumina Hiseq 4000 and Unigenes were obtained. The Unigenes were compared by comparison tool BLAST from NCBI in databases such as NR, STRING, SWISS-PROT (including Pfam), GO, COG, KEGG in order to obtain the corresponding annotation information. The expression amount of Unigenes obtained by sequencing in Chrysomyia Megacephala in six different growing periods was calculated by FPKM method, and the discrepant genes were screened according to the following standards: the log2 multiple absolute value of FPKM expression amount between two different growing periods must be larger than 1 (log2|FC|>1), and the false discovery rate must be less than 0.05. Results When the mean temperature was 25.6 ℃, Chrysomyia Megacephala emerged 6 d after they pupated. A total of 43 408 pieces of Unigenes were obtained and their mean length was 905 bp, of which 32 500, 18 720, 13 542, 9 191 and 18 720 pieces were annotated by NR, SWISS-PORT, Pfam, STRING and KEGG databases. According to the discrepant gene analysis of pupae in two different growing periods, the number of genes with variants ranged from 801 to 5 307, and the total number of discrepant genes was 45 676. Conclusion The gene expressions of the transcriptome data of Chrysomyia Megacephala pupae in different growing periods are different. The results provided a good foundation for further research on the transcriptome changes in each period of the pupae of sarcosaprophagous flies and provided the basis for exploring the genes associated with the growth of Chrysomyia Megacephala pupae.
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Affiliation(s)
- Q Y Wang
- Department of Forensic Medicine, School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - H L Zhang
- Department of Forensic Medicine, School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - Z Ren
- Department of Forensic Medicine, School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - Y B Liu
- Department of Forensic Medicine, School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - J Y Ji
- Department of Forensic Medicine, School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - J Huang
- Department of Forensic Medicine, School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
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Wu SC, Wang XJ, Ji JY, Geng G, Zhang ZH, Hou DL. [A preliminary investigation on a deep learning convolutional neural networks based pulmonary tuberculosis CT diagnostic model]. Zhonghua Jie He He Hu Xi Za Zhi 2021; 44:450-455. [PMID: 34865365 DOI: 10.3760/cma.j.cn112147-20210108-00026] [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] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Objective: To evaluate the clinical value of a pulmonary tuberculosis CT diagnostic model based on deep learning convolutional neural networks (CNN). Methods: From March 2017 to March 2018,a total of 1 764 patients with positive sputum for tuberculous bacterium and had received high-resolution chest CT scan in radiology department of Hebei province chest hospital were enrolled. Among them, 937 were male, and 827 were female, aging from 17-73 years (average 38.4). A total of 20 139 CT images (17 kinds of image features) classified by 4 radiologists were used as training dataset to create a tuberculosis CT CNN diagnostic model. The top 5 image features in training set were: infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion. A total of 302 images were randomly selected from the marked images as testing dataset. The diagnosis of 2 senior radiologists was taken as "golden standard". The differences of sensitivity and accuracy in CT diagnosis between the CNN diagnostic model and the radiologists were compared. The classification error types and numbers of the CNN diagnostic model were recorded. FROC(free response operating characteristic curve)curve was drawn and the highest diagnostic efficiency of the model was measured. Results: The diagnostic accuracy of infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion by the CNN diagnostic model were 95.33%(10 982/11 520), 73.68%(2 151/2 920), 73.07%(1 128/1544), 83.33%(1 020/1225)and 94.11%(814/865), respectively. The overall diagnostic sensitivity and accuracy of the CNN model were 95.49%(339/355)and 90.40%(339/375), respectively, and the corresponding values of radiologists were 93.80%(348/371)and 92.80%(348/375), respectively, and there was no statistical difference between the CNN model and the radiologists(sensitivity χ2=1.022,P=0.312;accuracy χ2=1.404,P=0.236). FROC curve showed that when sensitivity of the CNN model was 78% and FPI value was 2.48, it reached the highest diagnostic efficiency. The classification error of CNN diagnostic models was mainly confusion of fiber stripe components, cavitary pulmonary tuberculosis, caseous pneumonia and infiltrative pulmonary tuberculosis. Conclusions: The CNN-based pulmonary tuberculosis CT diagnostic model exhibited high sensitivity and accuracy (95.49% and 90.40% respectively). It could assist radiologists in CT diagnosis of pulmonary tuberculosis and deserve further clinical application.
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Affiliation(s)
- S C Wu
- Department of Radiology, Hebei Province Chest Hospital, Shijiazhuang 050041, China
| | - X J Wang
- Department of Radiology, Hebei Province Chest Hospital, Shijiazhuang 050041, China
| | - J Y Ji
- Department of Radiology, Hebei Province Chest Hospital, Shijiazhuang 050041, China
| | - G Geng
- Department of Radiology, Hebei Province Chest Hospital, Shijiazhuang 050041, China
| | - Z H Zhang
- Department of Radiology, Hebei Province Chest Hospital, Shijiazhuang 050041, China
| | - D L Hou
- Department of Radiology, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing 101149, China
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Abstract
We have developed a software package, namely, PASP (Property Analysis and Simulation Package for materials), to analyze the structural, electronic, magnetic, and thermodynamic properties of complex condensed matter systems. Our package integrates several functionalities including symmetry analysis, global structure searching methods, effective Hamiltonian methods, and Monte Carlo simulation methods. In conjunction with first-principles calculations, PASP has been successfully applied to diverse physical systems. In this paper, we give a brief introduction to its main features and underlying theoretical formulism. Some typical applications are provided to demonstrate the usefulness, high efficiency, and reliability of PASP. We expect that further developments will make PASP a general-purpose tool for material simulation and property calculation of condensed matters.
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Affiliation(s)
- Feng Lou
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
| | - X Y Li
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
| | - J Y Ji
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
| | - H Y Yu
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
| | - J S Feng
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
| | - X G Gong
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
| | - H J Xiang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, China
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Sun J, Wang X, Xu RG, Mao D, Shen D, Wang X, Qiu Y, Han Y, Lu X, Li Y, Che Q, Zheng L, Peng P, Kang X, Zhu R, Jia Y, Wang Y, Liu LP, Chang Z, Ji JY, Wang Z, Liu Q, Li S, Sun FL, Ni JQ. HP1c regulates development and gut homeostasis by suppressing Notch signaling through Su(H). EMBO Rep 2021; 22:e51298. [PMID: 33594776 DOI: 10.15252/embr.202051298] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 01/01/2021] [Accepted: 01/13/2021] [Indexed: 12/30/2022] Open
Abstract
Notch signaling and epigenetic factors are known to play critical roles in regulating tissue homeostasis in most multicellular organisms, but how Notch signaling coordinates with epigenetic modulators to control differentiation remains poorly understood. Here, we identify heterochromatin protein 1c (HP1c) as an essential epigenetic regulator of gut homeostasis in Drosophila. Specifically, we observe that HP1c loss-of-function phenotypes resemble those observed after Notch signaling perturbation and that HP1c interacts genetically with components of the Notch pathway. HP1c represses the transcription of Notch target genes by directly interacting with Suppressor of Hairless (Su(H)), the key transcription factor of Notch signaling. Moreover, phenotypes caused by depletion of HP1c in Drosophila can be rescued by expressing human HP1γ, suggesting that HP1γ functions similar to HP1c in Drosophila. Taken together, our findings reveal an essential role of HP1c in normal development and gut homeostasis by suppressing Notch signaling.
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Affiliation(s)
- Jin Sun
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Xia Wang
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,School of Life Sciences, Peking University, Beijing, China
| | - Rong-Gang Xu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Decai Mao
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Sichuan Academy of Grassland Science, Chengdu, China
| | - Da Shen
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Xin Wang
- Institute for TCM-X, MOE Key Laboratory of Bioinformatics/Bioinformatics Division, BNRIST, Department of Automation, Tsinghua University, Beijing, China
| | - Yuhao Qiu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, China
| | - Yuting Han
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Xinyi Lu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Yutong Li
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Qinyun Che
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Li Zheng
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Ping Peng
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, China
| | - Xuan Kang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Advanced Institute of Translational Medicine, Tongji University, Shanghai, China
| | - Ruibao Zhu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, China
| | - Yu Jia
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Tsinghua University-Peking University Joint Center for Life Sciences, Beijing, China
| | - Yinyin Wang
- State Key Laboratory of Membrane Biology, School of Medicine and the School of Life Sciences, Tsinghua University, Beijing, China
| | - Lu-Ping Liu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China
| | - Zhijie Chang
- State Key Laboratory of Membrane Biology, School of Medicine and the School of Life Sciences, Tsinghua University, Beijing, China
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX, USA
| | - Zhao Wang
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Qingfei Liu
- School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Shao Li
- Institute for TCM-X, MOE Key Laboratory of Bioinformatics/Bioinformatics Division, BNRIST, Department of Automation, Tsinghua University, Beijing, China
| | - Fang-Lin Sun
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Advanced Institute of Translational Medicine, Tongji University, Shanghai, China
| | - Jian-Quan Ni
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing, China.,Tsingdao Advanced Research Institute, Tongji University, Qingdao, China
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Luo X, Zhang WF, Yang L, Qian EF, Yang MQ, Zhang H, Ji JY, Huang J. [Polymorphism and Forensic Application of 11 Y-SNP in Guizhou Shui Ethnic Group]. Fa Yi Xue Za Zhi 2021; 36:791-796. [PMID: 33550727 DOI: 10.12116/j.issn.1004-5619.2020.06.008] [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] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Indexed: 11/30/2022]
Abstract
Abstract Objective To investigate the frequency distribution features of 11 Y-SNP of Guizhou Shui ethnic group, explore its genetic relationship with other ethnic groups and evaluate its forensic application value. Methods Multiplex amplification of the 11 Y-SNP of samples of 180 unrelated male individuals from Guizhou Shui ethnic group was performed with microsequencing technique. The frequency of haplogroup was calculated by direct counting method, and principal component analysis (PCA) of Guizhou Shui ethnic group and reference ethnic groups was performed by using Multi-variate statistical package (MVSP). The Fst genetic distance between Guizhou Shui ethnic group and other ethnic groups was calculated with Arlequin v3.5. The phylogenetic tree was established with MEGA 4.0 software according to the Fst value. Results Six types of Y chromosome haplogroups were observed in total. Among which, the distribution frequency of O-M175 haplogroup was the highest (71.11%), followed by C-M130 (25.00%), and D-M174 (3.89%). O1b-M268 (31.11%) and O2a2-IMS-JST021354 (28.33%) had a relatively high distribution frequency in O haplogroup. The paternal relationship between Guizhou Shui ethnic group and Guizhou Gelao ethnic group in the same language group was the closest. Conclusion The distribution of Y-SNP haplogroup of the Shui ethnic group in Guizhou has certain specificity, which can provide basic data for forensic biogeographic inference.
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Affiliation(s)
- X Luo
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - W F Zhang
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - L Yang
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - E F Qian
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - M Q Yang
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - H Zhang
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - J Y Ji
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
| | - J Huang
- School of Forensic Medicine, Guizhou Medical University, Guiyang 550004, China
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Bhandari B, Bian J, Bilton K, Callahan C, Chaves J, Chen H, Cline D, Cooper RL, Danielson D, Danielson J, Dokania N, Elliott S, Fernandes S, Gardiner S, Garvey G, Gehman V, Giuliani F, Glavin S, Gold M, Grant C, Guardincerri E, Haines T, Higuera A, Ji JY, Kadel R, Kamp N, Karlin A, Ketchum W, Koerner LW, Lee D, Lee K, Liu Q, Locke S, Louis WC, Manalaysay A, Maricic J, Martin E, Martinez MJ, Martynenko S, Mauger C, McGrew C, Medina J, Medina PJ, Mills A, Mills G, Mirabal-Martinez J, Olivier A, Pantic E, Philipbar B, Pitcher C, Radeka V, Ramsey J, Rielage K, Rosen M, Sanchez AR, Shin J, Sinnis G, Smy M, Sondheim W, Stancu I, Sterbenz C, Sun Y, Svoboda R, Taylor C, Teymourian A, Thorn C, Tull CE, Tzanov M, Van de Water RG, Walker D, Walsh N, Wang H, Wang Y, Yanagisawa C, Yarritu A, Yoo J. First Measurement of the Total Neutron Cross Section on Argon between 100 and 800 MeV. Phys Rev Lett 2019; 123:042502. [PMID: 31491269 DOI: 10.1103/physrevlett.123.042502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/23/2019] [Indexed: 06/10/2023]
Abstract
We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-h exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is 0.91±0.10(stat)±0.09(syst) b. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages, where the energy averaged cross sections in this range are 0.60 and 0.68 b, respectively.
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Affiliation(s)
- B Bhandari
- Department of Physics, University of Houston, Houston, Texas 77204, USA
| | - J Bian
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - K Bilton
- Department of Physics, University of California, Davis, California 95616, USA
| | - C Callahan
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - J Chaves
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - H Chen
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D Cline
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - R L Cooper
- Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA
| | - D Danielson
- Department of Physics, University of California, Davis, California 95616, USA
| | - J Danielson
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - N Dokania
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - S Elliott
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Fernandes
- Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - S Gardiner
- Department of Physics, University of California, Davis, California 95616, USA
| | - G Garvey
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - V Gehman
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - F Giuliani
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - S Glavin
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - M Gold
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - C Grant
- Department of Physics, Boston University, Boston, Massachusetts 02215, USA
| | - E Guardincerri
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T Haines
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Higuera
- Department of Physics, University of Houston, Houston, Texas 77204, USA
| | - J Y Ji
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - R Kadel
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - N Kamp
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Karlin
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - W Ketchum
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - L W Koerner
- Department of Physics, University of Houston, Houston, Texas 77204, USA
| | - D Lee
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K Lee
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Q Liu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Locke
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - W C Louis
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Manalaysay
- Department of Physics, University of California, Davis, California 95616, USA
| | - J Maricic
- Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
| | - E Martin
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - M J Martinez
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - S Martynenko
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - C Mauger
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - C McGrew
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - J Medina
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - P J Medina
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Mills
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - G Mills
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | | | - A Olivier
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - E Pantic
- Department of Physics, University of California, Davis, California 95616, USA
| | - B Philipbar
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - C Pitcher
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - V Radeka
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J Ramsey
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K Rielage
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Rosen
- Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
| | - A R Sanchez
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Shin
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - G Sinnis
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - M Smy
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - W Sondheim
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - I Stancu
- Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - C Sterbenz
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Y Sun
- Department of Physics and Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA
| | - R Svoboda
- Department of Physics, University of California, Davis, California 95616, USA
| | - C Taylor
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A Teymourian
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - C Thorn
- Brookhaven National Laboratory, Upton, New York 11973, USA
| | - C E Tull
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Tzanov
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - R G Van de Water
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D Walker
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - N Walsh
- Department of Physics, University of California, Davis, California 95616, USA
| | - H Wang
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Y Wang
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - C Yanagisawa
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - A Yarritu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J Yoo
- Department of Physics, University of Houston, Houston, Texas 77204, USA
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10
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Zhao B, Du F, Xu P, Shu C, Sankaran B, Bell SL, Liu M, Lei Y, Gao X, Fu X, Zhu F, Liu Y, Laganowsky A, Zheng X, Ji JY, West AP, Watson RO, Li P. A conserved PLPLRT/SD motif of STING mediates the recruitment and activation of TBK1. Nature 2019; 569:718-722. [PMID: 31118511 PMCID: PMC6596994 DOI: 10.1038/s41586-019-1228-x] [Citation(s) in RCA: 193] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 04/26/2019] [Indexed: 01/09/2023]
Abstract
Nucleic acids from bacteria or viruses induce potent immune responses in infected cells1-4. The detection of pathogen-derived nucleic acids is a central strategy by which the host senses infection and initiates protective immune responses5,6. Cyclic GMP-AMP synthase (cGAS) is a double-stranded DNA sensor7,8. It catalyses the synthesis of cyclic GMP-AMP (cGAMP)9-12, which stimulates the induction of type I interferons through the STING-TBK1-IRF-3 signalling axis13-15. STING oligomerizes after binding of cGAMP, leading to the recruitment and activation of the TBK1 kinase8,16. The IRF-3 transcription factor is then recruited to the signalling complex and activated by TBK18,17-20. Phosphorylated IRF-3 translocates to the nucleus and initiates the expression of type I interferons21. However, the precise mechanisms that govern activation of STING by cGAMP and subsequent activation of TBK1 by STING remain unclear. Here we show that a conserved PLPLRT/SD motif within the C-terminal tail of STING mediates the recruitment and activation of TBK1. Crystal structures of TBK1 bound to STING reveal that the PLPLRT/SD motif binds to the dimer interface of TBK1. Cell-based studies confirm that the direct interaction between TBK1 and STING is essential for induction of IFNβ after cGAMP stimulation. Moreover, we show that full-length STING oligomerizes after it binds cGAMP, and highlight this as an essential step in the activation of STING-mediated signalling. These findings provide a structural basis for the development of STING agonists and antagonists for the treatment of cancer and autoimmune disorders.
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Affiliation(s)
- Baoyu Zhao
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Fenglei Du
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Pengbiao Xu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Chang Shu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Banumathi Sankaran
- Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Samantha L Bell
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, TX, USA
| | - Mengmeng Liu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Yuanjiu Lei
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, TX, USA
| | - Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Xiaofeng Fu
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Fanxiu Zhu
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Yang Liu
- Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Xueyun Zheng
- Department of Chemistry, Texas A&M University, College Station, TX, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - A Phillip West
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, TX, USA
| | - Robert O Watson
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, College Station, TX, USA
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.
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11
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Affiliation(s)
- Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, 77843, USA.
| | - Chun Han
- Weill Institute for Cell and Molecular Biology and Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, 14853, USA
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
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12
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Abstract
Multiple large-scale epidemiological studies have identified obesity as an important risk factor for a variety of human cancers, particularly cancers of the uterus, gallbladder, kidney, liver, colon, and ovary, but there is much uncertainty regarding how obesity increases the cancer risks. Given that obesity has been consistently identified as a major risk factor for uterine tumors, the most common malignancies of the female reproductive system, we use uterine tumors as a pathological context to survey the relevant literature and propose a novel hypothesis: chronic downregulation of the cyclin-dependent kinase 8 (CDK8) module, composed of CDK8 (or its paralog CDK19), Cyclin C, MED12 (or MED12L), and MED13 (or MED13L), by elevated insulin or insulin-like growth factor signaling in obese women may increase the chances to dysregulate the activities of transcription factors regulated by the CDK8 module, thereby increasing the risk of uterine tumors. Although we focus on endometrial cancer and uterine leiomyomas (or fibroids), two major forms of uterine tumors, our model may offer additional insights into how obesity increases the risk of other types of cancers and diseases. To illustrate the power of model organisms for studying human diseases, here we place more emphasis on the findings obtained from Drosophila melanogaster.
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Affiliation(s)
- Xiao Li
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Mengmeng Liu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA.
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13
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Gao X, Xie XJ, Hsu FN, Li X, Liu M, Hemba-Waduge RUS, Xu W, Ji JY. CDK8 mediates the dietary effects on developmental transition in Drosophila. Dev Biol 2018; 444:62-70. [PMID: 30352217 PMCID: PMC6263851 DOI: 10.1016/j.ydbio.2018.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 07/14/2018] [Revised: 09/08/2018] [Accepted: 10/07/2018] [Indexed: 01/29/2023]
Abstract
The complex interplay between genetic and environmental factors, such as diet and lifestyle, defines the initiation and progression of multifactorial diseases, including cancer, cardiovascular and metabolic diseases, and neurological disorders. Given that most of the studies have been performed in controlled experimental settings to ensure the consistency and reproducibility, the impacts of environmental factors, such as dietary perturbation, on the development of animals with different genotypes and the pathogenesis of these diseases remain poorly understood. By analyzing the cdk8 and cyclin C (cycC) mutant larvae in Drosophila, we have previously reported that the CDK8-CycC complex coordinately regulates lipogenesis by repressing dSREBP (sterol regulatory element-binding protein)-activated transcription and developmental timing by activating EcR (ecdysone receptor)-dependent gene expression. Here we report that dietary nutrients, particularly proteins and carbohydrates, modulate the developmental timing through the CDK8/CycC/EcR pathway. We observed that cdk8 and cycC mutants are sensitive to the levels of dietary proteins and seven amino acids (arginine, glutamine, isoleucine, leucine, methionine, threonine, and valine). Those mutants are also sensitive to dietary carbohydrates, and they are more sensitive to monosaccharides than disaccharides. These results suggest that CDK8-CycC mediates the dietary effects on lipid metabolism and developmental timing in Drosophila larvae.
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Affiliation(s)
- Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Xiao-Jun Xie
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Fu-Ning Hsu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Xiao Li
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Mengmeng Liu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | | | - Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA.
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14
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Zheng Y, Xue Y, Ren X, Liu M, Li X, Jia Y, Niu Y, Ni JQ, Zhang Y, Ji JY. The Lysine Demethylase dKDM2 Is Non-essential for Viability, but Regulates Circadian Rhythms in Drosophila. Front Genet 2018; 9:354. [PMID: 30233643 PMCID: PMC6131532 DOI: 10.3389/fgene.2018.00354] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/15/2018] [Indexed: 12/29/2022] Open
Abstract
Post-translational modification of histones, such as histone methylation controlled by specific methyltransferases and demethylases, play critical roles in modulating chromatin dynamics and transcription in eukaryotes. Misregulation of histone methylation can lead to aberrant gene expression, thereby contributing to abnormal development and diseases such as cancer. As such, the mammalian lysine-specific demethylase 2 (KDM2) homologs, KDM2A and KDM2B, are either oncogenic or tumor suppressive depending on specific pathological contexts. However, the role of KDM2 proteins during development remains poorly understood. Unlike vertebrates, Drosophila has only one KDM2 homolog (dKDM2), but its functions in vivo remain elusive due to the complexities of the existing mutant alleles. To address this problem, we have generated two dKdm2 null alleles using the CRISPR/Cas9 technique. These dKdm2 homozygous mutants are fully viable and fertile, with no developmental defects observed under laboratory conditions. However, the dKdm2 null mutant adults display defects in circadian rhythms. Most of the dKdm2 mutants become arrhythmic under constant darkness, while the circadian period of the rhythmic mutant flies is approximately 1 h shorter than the control. Interestingly, lengthened circadian periods are observed when dKDM2 is overexpressed in circadian pacemaker neurons. Taken together, these results demonstrate that dKdm2 is not essential for viability; instead, dKDM2 protein plays important roles in regulating circadian rhythms in Drosophila. Further analyses of the molecular mechanisms of dKDM2 and its orthologs in vertebrates regarding the regulation of circadian rhythms will advance our understanding of the epigenetic regulations of circadian clocks.
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Affiliation(s)
- Yani Zheng
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, United States
| | - Yongbo Xue
- Department of Biology, University of Nevada, Reno, Reno, NV, United States
| | - Xingjie Ren
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Mengmeng Liu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, United States
| | - Xiao Li
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, United States
| | - Yu Jia
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Ye Niu
- Department of Biology, University of Nevada, Reno, Reno, NV, United States
| | - Jian-Quan Ni
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Yong Zhang
- Department of Biology, University of Nevada, Reno, Reno, NV, United States
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, United States
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15
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Ma T, Cheng Y, Roltsch Hellard E, Wang X, Lu J, Gao X, Huang CCY, Wei XY, Ji JY, Wang J. Bidirectional and long-lasting control of alcohol-seeking behavior by corticostriatal LTP and LTD. Nat Neurosci 2018; 21:373-383. [PMID: 29434375 PMCID: PMC5857235 DOI: 10.1038/s41593-018-0081-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/08/2018] [Indexed: 12/21/2022]
Abstract
Addiction is proposed to arise from alterations in synaptic strength via mechanisms of long-term potentiation (LTP) and depression (LTD). However, the causality between these synaptic processes and addictive behaviors is difficult to demonstrate. Here we report that LTP and LTD induction altered operant alcohol self-administration, a motivated drug-seeking behavior. We first induced LTP by pairing presynaptic glutamatergic stimulation with optogenetic postsynaptic depolarization in the dorsomedial striatum, a brain region known to control goal-directed behavior. Blockade of this LTP by NMDA-receptor inhibition unmasked an endocannabinoid-dependent LTD. In vivo application of the LTP-inducing protocol caused a long-lasting increase in alcohol-seeking behavior, while the LTD protocol decreased this behavior. We further identified that optogenetic LTP and LTD induction at cortical inputs onto striatal dopamine D1 receptor-expressing neurons controlled these behavioral changes. Our results demonstrate a causal link between synaptic plasticity and alcohol-seeking behavior and suggest that modulation of this plasticity may inspire a therapeutic strategy for addiction.
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Affiliation(s)
- Tengfei Ma
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Yifeng Cheng
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Emily Roltsch Hellard
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Xuehua Wang
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Jiayi Lu
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Cathy C Y Huang
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Xiao-Yan Wei
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Jun Wang
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, USA.
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16
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Guo X, Shu C, Li H, Pei Y, Woo SL, Zheng J, Liu M, Xu H, Botchlett R, Guo T, Cai Y, Gao X, Zhou J, Chen L, Li Q, Xiao X, Xie L, Zhang KK, Ji JY, Huo Y, Meng F, Alpini G, Li P, Wu C. Cyclic GMP-AMP Ameliorates Diet-induced Metabolic Dysregulation and Regulates Proinflammatory Responses Distinctly from STING Activation. Sci Rep 2017; 7:6355. [PMID: 28743914 PMCID: PMC5526935 DOI: 10.1038/s41598-017-05884-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 05/26/2017] [Indexed: 01/22/2023] Open
Abstract
Endogenous cyclic GMP-AMP (cGAMP) binds and activates STING to induce type I interferons. However, whether cGAMP plays any roles in regulating metabolic homeostasis remains unknown. Here we show that exogenous cGAMP ameliorates obesity-associated metabolic dysregulation and uniquely alters proinflammatory responses. In obese mice, treatment with cGAMP significantly decreases diet-induced proinflammatory responses in liver and adipose tissues and ameliorates metabolic dysregulation. Strikingly, cGAMP exerts cell-type-specific anti-inflammatory effects on macrophages, hepatocytes, and adipocytes, which is distinct from the effect of STING activation by DMXAA on enhancing proinflammatory responses. While enhancing insulin-stimulated Akt phosphorylation in hepatocytes and adipocytes, cGAMP weakens the effects of glucagon on stimulating hepatocyte gluconeogenic enzyme expression and glucose output and blunts palmitate-induced hepatocyte fat deposition in an Akt-dependent manner. Taken together, these results suggest an essential role for cGAMP in linking innate immunity and metabolic homeostasis, indicating potential applications of cGAMP in treating obesity-associated inflammatory and metabolic diseases.
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Affiliation(s)
- Xin Guo
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Chang Shu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Honggui Li
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Ya Pei
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Shih-Lung Woo
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Juan Zheng
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Mengyang Liu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Hang Xu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Rachel Botchlett
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Ting Guo
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Yuli Cai
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, 77843, USA
| | - Jing Zhou
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Lu Chen
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Qifu Li
- Department of Endocrinology and the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Xiaoqiu Xiao
- Department of Endocrinology and the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.,The Laboratory of Lipid & Glucose Metabolism, the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Linglin Xie
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA
| | - Ke K Zhang
- Department of Pathology, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202, USA
| | - Jun-Yuan Ji
- Department of Endocrinology and the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Yuqing Huo
- Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Fanyin Meng
- Departments of Medical Physiology and Medicine, Texas A&M University Health Science Center, Temple, TX, 76504, USA
| | - Gianfranco Alpini
- Departments of Medical Physiology and Medicine, Texas A&M University Health Science Center, Temple, TX, 76504, USA
| | - Pingwei Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77843, USA.
| | - Chaodong Wu
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, 77843, USA.
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17
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Wang R, Zheng P, Zhang M, Zhao HP, Ji JY, Zhou XX, Li W. Bioaugmentation of nitrate-dependent anaerobic ferrous oxidation by heterotrophic denitrifying sludge addition: A promising way for promotion of chemoautotrophic denitrification. Bioresour Technol 2015; 197:410-415. [PMID: 26348287 DOI: 10.1016/j.biortech.2015.08.135] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 08/22/2015] [Accepted: 08/25/2015] [Indexed: 06/05/2023]
Abstract
Nitrate-dependent anaerobic ferrous oxidation (NAFO) is a new and valuable bio-process for the treatment of wastewaters with low C/N ratio, and the NAFO process is in state of the art. The heterotrophic denitrifying sludge (HDS), possessing NAFO activity, was used as bioaugmentation to enhance NAFO efficiency. At a dosage of 6% (V/V), the removal of nitrate and ferrous was 2.4 times and 2.3 times of as primary, and the volumetric removal rate (VRR) of nitrate and ferrous was 2.4 times and 2.2 times of as primary. Tracing experiments of HDS indicated that the bioaugmentation on NAFO reactor was resulted from the NAFO activity by HDS itself. The predominant bacteria in HDS were identified as Thauera (52.5%) and Hyphomicrobium (20.0%) which were typical denitrifying bacteria and had potential ability to oxidize ferrous. In conclusion, HDS could serve as bioaugmentation or a new seeding sludge for operating high-efficiency NAFO reactors.
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Affiliation(s)
- Ru Wang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, PR China
| | - Ping Zheng
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, PR China.
| | - Meng Zhang
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, PR China
| | - He-Ping Zhao
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, PR China
| | - Jun-Yuan Ji
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266003, PR China
| | - Xiao-Xin Zhou
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, PR China
| | - Wei Li
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, PR China
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18
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Wang T, Guo S, Liu Z, Wu L, Li M, Yang J, Chen R, Liu X, Xu H, Cai S, Chen H, Li W, Xu S, Wang L, Hu Z, Zhuang Q, Wang L, Wu K, Liu J, Ye Z, Ji JY, Wang C, Chen K. CAMK2N1 inhibits prostate cancer progression through androgen receptor-dependent signaling. Oncotarget 2015; 5:10293-306. [PMID: 25296973 PMCID: PMC4279373 DOI: 10.18632/oncotarget.2511] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/24/2014] [Indexed: 12/13/2022] Open
Abstract
Castration resistance is a major obstacle to hormonal therapy for prostate cancer patients. Although androgen independence of prostate cancer growth is a known contributing factor to endocrine resistance, the mechanism of androgen receptor deregulation in endocrine resistance is still poorly understood. Herein, the CAMK2N1 was shown to contribute to the human prostate cancer cell growth and survival through AR-dependent signaling. Reduced expression of CAMK2N1 was correlated to recurrence-free survival of prostate cancer patients with high levels of AR expression in their tumor. CAMK2N1 and AR signaling form an auto-regulatory negative feedback loop: CAMK2N1 expression was down-regulated by AR activation; while CAMK2N1 inhibited AR expression and transactivation through CAMKII and AKT pathways. Knockdown of CAMK2N1 in prostate cancer cells alleviated Casodex inhibition of cell growth, while re-expression of CAMK2N1 in castration-resistant cells sensitized the cells to Casodex treatment. Taken together, our findings suggest that CAMK2N1 plays a tumor suppressive role and serves as a crucial determinant of the resistance of prostate cancer to endocrine therapies.
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Affiliation(s)
- Tao Wang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shuiming Guo
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhuo Liu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Licheng Wu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Mingchao Li
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jun Yang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ruibao Chen
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiaming Liu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hua Xu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shaoxin Cai
- Department of Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hui Chen
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Weiyong Li
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shaohua Xu
- Department of Gynecology, Shanghai First Matenity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
| | - Liang Wang
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhiquan Hu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qianyuan Zhuang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Liping Wang
- Kimmel Cancer Center, Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Kongming Wu
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jihong Liu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhangqun Ye
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX, USA
| | - Chenguang Wang
- Key Laboratory of Tianjin Radiation and Molecular Nuclear Medicine; Institute of Radiation Medicine, Peking Union Medical College & Chinese Academy of Medical Sciences, Tianjin, China
| | - Ke Chen
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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Xie XJ, Hsu FN, Gao X, Xu W, Ni JQ, Xing Y, Huang L, Hsiao HC, Zheng H, Wang C, Zheng Y, Xiaoli AM, Yang F, Bondos SE, Ji JY. CDK8-Cyclin C Mediates Nutritional Regulation of Developmental Transitions through the Ecdysone Receptor in Drosophila. PLoS Biol 2015. [PMID: 26222308 PMCID: PMC4519132 DOI: 10.1371/journal.pbio.1002207] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The steroid hormone ecdysone and its receptor (EcR) play critical roles in orchestrating developmental transitions in arthropods. However, the mechanism by which EcR integrates nutritional and developmental cues to correctly activate transcription remains poorly understood. Here, we show that EcR-dependent transcription, and thus, developmental timing in Drosophila, is regulated by CDK8 and its regulatory partner Cyclin C (CycC), and the level of CDK8 is affected by nutrient availability. We observed that cdk8 and cycC mutants resemble EcR mutants and EcR-target genes are systematically down-regulated in both mutants. Indeed, the ability of the EcR-Ultraspiracle (USP) heterodimer to bind to polytene chromosomes and the promoters of EcR target genes is also diminished. Mass spectrometry analysis of proteins that co-immunoprecipitate with EcR and USP identified multiple Mediator subunits, including CDK8 and CycC. Consistently, CDK8-CycC interacts with EcR-USP in vivo; in particular, CDK8 and Med14 can directly interact with the AF1 domain of EcR. These results suggest that CDK8-CycC may serve as transcriptional cofactors for EcR-dependent transcription. During the larval–pupal transition, the levels of CDK8 protein positively correlate with EcR and USP levels, but inversely correlate with the activity of sterol regulatory element binding protein (SREBP), the master regulator of intracellular lipid homeostasis. Likewise, starvation of early third instar larvae precociously increases the levels of CDK8, EcR and USP, yet down-regulates SREBP activity. Conversely, refeeding the starved larvae strongly reduces CDK8 levels but increases SREBP activity. Importantly, these changes correlate with the timing for the larval–pupal transition. Taken together, these results suggest that CDK8-CycC links nutrient intake to developmental transitions (EcR activity) and fat metabolism (SREBP activity) during the larval–pupal transition. During the larval-pupal transition in Drosophila, CDK8-CycC helps to link nutrient intake to development by activating ecdysone receptor-dependent transcription and to fat metabolism by inhibiting SREBP-activated gene expression. Arthropods are estimated to account for over 80% of animal species on earth. Characterized by their rigid exoskeletons, juvenile arthropods must periodically shed their thick outer cuticles by molting in order to grow. The steroid hormone ecdysone plays an essential role in regulating the timing of developmental transitions, but exactly how ecdysone and its receptor EcR activates transcription correctly after integrating nutritional and developmental cues remains unknown. Our developmental genetic analyses of two Drosophila mutants, cdk8 and cycC, show that they are lethal during the prepupal stage, with aberrant accumulation of fat and a severely delayed larval–pupal transition. As we have reported previously, CDK8-CycC inhibits fat accumulation by directly inactivating SREBP, a master transcription factor that controls the expression of lipogenic genes, which explains the abnormal fat accumulation in the cdk8 and cycC mutants. We find that CDK8 and CycC are required for EcR to bind to its target genes, serving as transcriptional cofactors for EcR-dependent gene expression. The expression of EcR target genes is compromised in cdk8 and cycC mutants and underpins the retarded pupariation phenotype. Starvation of feeding larvae precociously up-regulates CDK8 and EcR, prematurely down-regulates SREBP activity, and leads to early pupariation, whereas re-feeding starved larvae has opposite effects. Taken together, these results suggest that CDK8 and CycC play important roles in coordinating nutrition intake with fat metabolism by directly inhibiting SREBP-dependent gene expression and regulating developmental timing by activating EcR-dependent transcription in Drosophila.
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Affiliation(s)
- Xiao-Jun Xie
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Fu-Ning Hsu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Los Angeles, United States of America
| | - Jian-Quan Ni
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Yue Xing
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Liying Huang
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Los Angeles, United States of America
| | - Hao-Ching Hsiao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Haiyan Zheng
- Biological Mass Spectrometry Facility, Robert Wood Johnson Medical School and Rutgers, the State University of New Jersey, Frelinghuysen Road, Piscataway, New Jersey, United States of America
| | - Chenguang Wang
- Key Laboratory of Tianjin Radiation and Molecular Nuclear Medicine; Institute of Radiation Medicine, Peking Union Medical College & Chinese Academy of Medical Sciences, Tianjin, China
| | - Yani Zheng
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Alus M. Xiaoli
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Fajun Yang
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Sarah E. Bondos
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
- Department of Biosciences, Rice University, Houston, Texas, United States of America
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
- * E-mail:
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20
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Ren X, Yang Z, Xu J, Sun J, Mao D, Hu Y, Yang SJ, Qiao HH, Wang X, Hu Q, Deng P, Liu LP, Ji JY, Li JB, Ni JQ. Enhanced specificity and efficiency of the CRISPR/Cas9 system with optimized sgRNA parameters in Drosophila. Cell Rep 2014; 9:1151-62. [PMID: 25437567 PMCID: PMC4250831 DOI: 10.1016/j.celrep.2014.09.044] [Citation(s) in RCA: 193] [Impact Index Per Article: 19.3] [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: 06/03/2014] [Revised: 08/22/2014] [Accepted: 09/24/2014] [Indexed: 12/13/2022] Open
Abstract
The CRISPR/Cas9 system has recently emerged as a powerful tool for functional genomic studies in Drosophila melanogaster. However, single-guide RNA (sgRNA) parameters affecting the specificity and efficiency of the system in flies are still not clear. Here, we found that off-target effects did not occur in regions of genomic DNA with three or more nucleotide mismatches to sgRNAs. Importantly, we document for a strong positive correlation between mutagenesis efficiency and sgRNA GC content of the six protospacer-adjacent motif-proximal nucleotides (PAMPNs). Furthermore, by injecting well-designed sgRNA plasmids at the optimal concentration we determined, we could efficiently generate mutations in four genes in one step. Finally, we generated null alleles of HP1a using optimized parameters through homology-directed repair and achieved an overall mutagenesis rate significantly higher than previously reported. Our work demonstrates a comprehensive optimization of sgRNA and promises to vastly simplify CRISPR/Cas9 experiments in Drosophila.
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Affiliation(s)
- Xingjie Ren
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Zhihao Yang
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jiang Xu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Fly Center, Tsinghua University, Beijing 100084, China; School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China; College of Bioengineering, Hubei University of Technology, Wuhan 430068, China
| | - Jin Sun
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Decai Mao
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China; Sichuan Academy of Grassland Science, Chengdu 611731, China
| | - Yanhui Hu
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Su-Juan Yang
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Huan-Huan Qiao
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xia Wang
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Qun Hu
- Tsinghua Fly Center, Tsinghua University, Beijing 100084, China
| | - Patricia Deng
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Lu-Ping Liu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Fly Center, Tsinghua University, Beijing 100084, China
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA
| | - Jin Billy Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
| | - Jian-Quan Ni
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China.
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21
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Abdulla A, Zhang Y, Hsu FN, Xiaoli AM, Zhao X, Yang EST, Ji JY, Yang F. Regulation of lipogenic gene expression by lysine-specific histone demethylase-1 (LSD1). J Biol Chem 2014; 289:29937-47. [PMID: 25190802 DOI: 10.1074/jbc.m114.573659] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [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: 01/08/2023] Open
Abstract
Dysregulation of lipid homeostasis is a common feature of several major human diseases, including type 2 diabetes and cardiovascular disease. However, because of the complex nature of lipid metabolism, the regulatory mechanisms remain poorly defined at the molecular level. As the key transcriptional activators of lipogenic genes, such as fatty acid synthase (FAS), sterol regulatory element-binding proteins (SREBPs) play a pivotal role in stimulating lipid biosynthesis. Several studies have shown that SREBPs are regulated by the NAD(+)-dependent histone deacetylase SIRT1, which forms a complex with the lysine-specific histone demethylase LSD1. Here, we show that LSD1 plays a role in regulating SREBP1-mediated gene expression. Multiple lines of evidence suggest that LSD1 is required for SREBP1-dependent activation of the FAS promoter in mammalian cells. LSD1 knockdown decreases SREBP-1a at the transcription level. Although LSD1 affects nuclear SREBP-1 abundance indirectly through SIRT1, it is also required for SREBP1 binding to the FAS promoter. As a result, LSD1 knockdown decreases triglyceride levels in hepatocytes. Taken together, these results show that LSD1 plays a role in regulating lipogenic gene expression, suggesting LSD1 as a potential target for treating dysregulation of lipid metabolism.
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Affiliation(s)
- Arian Abdulla
- From the Department of Medicine and Developmental & Molecular Biology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Yi Zhang
- From the Department of Medicine and Developmental & Molecular Biology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Fu-Ning Hsu
- the Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas 77843
| | - Alus M Xiaoli
- From the Department of Medicine and Developmental & Molecular Biology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Xiaoping Zhao
- From the Department of Medicine and Developmental & Molecular Biology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Ellen S T Yang
- From the Department of Medicine and Developmental & Molecular Biology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Jun-Yuan Ji
- the Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas 77843
| | - Fajun Yang
- From the Department of Medicine and Developmental & Molecular Biology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York 10461 and
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22
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Ren X, Yang Z, Mao D, Chang Z, Qiao HH, Wang X, Sun J, Hu Q, Cui Y, Liu LP, Ji JY, Xu J, Ni JQ. Performance of the Cas9 nickase system in Drosophila melanogaster. G3 (Bethesda) 2014; 4:1955-62. [PMID: 25128437 PMCID: PMC4199701 DOI: 10.1534/g3.114.013821] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [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] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 08/12/2014] [Indexed: 11/18/2022]
Abstract
Recent studies of the Cas9/sgRNA system in Drosophila melanogaster genome editing have opened new opportunities to generate site-specific mutant collections in a high-throughput manner. However, off-target effects of the system are still a major concern when analyzing mutant phenotypes. Mutations converting Cas9 to a DNA nickase have great potential for reducing off-target effects in vitro. Here, we demonstrated that injection of two plasmids encoding neighboring offset sgRNAs into transgenic Cas9(D10A) nickase flies efficiently produces heritable indel mutants. We then determined the effective distance between the two sgRNA targets and their orientations that affected the ability of the sgRNA pairs to generate mutations when expressed in the transgenic nickase flies. Interestingly, Cas9 nickase greatly reduces the ability to generate mutants with one sgRNA, suggesting that the application of Cas9 nickase and sgRNA pairs can almost avoid off-target effects when generating indel mutants. Finally, a defined piwi mutant allele is generated with this system through homology-directed repair. However, Cas9(D10A) is not as effective as Cas9 in replacing the entire coding sequence of piwi with two sgRNAs.
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Affiliation(s)
- Xingjie Ren
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Zhihao Yang
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Decai Mao
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Zai Chang
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Huan-Huan Qiao
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xia Wang
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jin Sun
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Qun Hu
- Tsinghua Fly Center, Tsinghua University, Beijing 100084, China
| | - Yan Cui
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Lu-Ping Liu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China Tsinghua Fly Center, Tsinghua University, Beijing 100084, China
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas 77843
| | - Jiang Xu
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China College of Bioengineering, Hubei University of Technology, Wuhan 430068, China
| | - Jian-Quan Ni
- Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China
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23
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Zhao X, Xiaoli, Zong H, Abdulla A, Yang EST, Wang Q, Ji JY, Pessin JE, Das BC, Yang F. Inhibition of SREBP transcriptional activity by a boron-containing compound improves lipid homeostasis in diet-induced obesity. Diabetes 2014; 63:2464-73. [PMID: 24608444 PMCID: PMC4066337 DOI: 10.2337/db13-0835] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dysregulation of lipid homeostasis is intimately associated with obesity, type 2 diabetes, and cardiovascular diseases. Sterol regulatory-element binding proteins (SREBPs) are the master regulators of lipid biosynthesis. Previous studies have shown that the conserved transcriptional cofactor Mediator complex is critically required for the SREBP transcriptional activity, and recruitment of the Mediator complex to the SREBP transactivation domains (TADs) is through the MED15-KIX domain. Recently, we have synthesized several boron-containing small molecules. Among these novel compounds, BF175 can specifically block the binding of MED15-KIX to SREBP1a-TAD in vitro, resulting in an inhibition of the SREBP transcriptional activity and a decrease of SREBP target gene expression in cultured hepatocytes. Furthermore, BF175 can improve lipid homeostasis in the mouse model of diet-induced obesity. Compared with the control, BF175 treatment decreased the expression of SREBP target genes in mouse livers and decreased hepatic and blood levels of lipids. These results suggest that blocking the interaction between SREBP-TADs and the Mediator complex by small molecules may represent a novel approach for treating diseases with aberrant lipid homeostasis.
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Affiliation(s)
- Xiaoping Zhao
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NYDepartment of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaoli
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Haihong Zong
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Arian Abdulla
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
| | - Ellen S T Yang
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY
| | - Qun Wang
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX
| | - Jeffrey E Pessin
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY
| | - Bhaskar C Das
- Division of Hematology and Oncology, Department of Medicine, University of Kansas Medical Center, Kansas City, KS
| | - Fajun Yang
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NYDepartment of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx, NY
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Zhang T, Liao Y, Hsu FN, Zhang R, Searle JS, Pei X, Li X, Ryoo HD, Ji JY, Du W. Hyperactivated Wnt signaling induces synthetic lethal interaction with Rb inactivation by elevating TORC1 activities. PLoS Genet 2014; 10:e1004357. [PMID: 24809668 PMCID: PMC4014429 DOI: 10.1371/journal.pgen.1004357] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/24/2014] [Indexed: 12/31/2022] Open
Abstract
Inactivation of the Rb tumor suppressor can lead to increased cell proliferation or cell death depending on specific cellular context. Therefore, identification of the interacting pathways that modulate the effect of Rb loss will provide novel insights into the roles of Rb in cancer development and promote new therapeutic strategies. Here, we identify a novel synthetic lethal interaction between Rb inactivation and deregulated Wg/Wnt signaling through unbiased genetic screens. We show that a weak allele of axin, which deregulates Wg signaling and increases cell proliferation without obvious effects on cell fate specification, significantly alters metabolic gene expression, causes hypersensitivity to metabolic stress induced by fasting, and induces synergistic apoptosis with mutation of fly Rb ortholog, rbf. Furthermore, hyperactivation of Wg signaling by other components of the Wg pathway also induces synergistic apoptosis with rbf. We show that hyperactivated Wg signaling significantly increases TORC1 activity and induces excessive energy stress with rbf mutation. Inhibition of TORC1 activity significantly suppressed synergistic cell death induced by hyperactivated Wg signaling and rbf inactivation, which is correlated with decreased energy stress and decreased induction of apoptotic regulator expression. Finally the synthetic lethality between Rb and deregulated Wnt signaling is conserved in mammalian cells and that inactivation of Rb and APC induces synergistic cell death through a similar mechanism. These results suggest that elevated TORC1 activity and metabolic stress underpin the evolutionarily conserved synthetic lethal interaction between hyperactivated Wnt signaling and inactivated Rb tumor suppressor. Inactivation of Rb tumor suppressor is common in cancers. Therefore, identification of genes and pathways that are synthetic lethal with Rb will provide new insights into the role of Rb in cancer development and promote the development of novel therapeutic approaches. Here we identified a novel synthetic lethal interaction between Rb inactivation and hyperactivated Wnt signaling and showed that this synthetic lethal interaction is conserved in mammalian systems. We demonstrate that hyperactivated Wnt signaling activate TORC1 activity and induce excessive energy stress with inactivated Rb tumor suppressor, which underpins the evolutionarily conserved synthetic lethal interaction. This study provides novel insights into the interactions between the Rb, Wnt, and mTOR pathways in regulating cellular energy balance, cell growth, and survival.
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Affiliation(s)
- Tianyi Zhang
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
| | - Yang Liao
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
| | - Fu-Ning Hsu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Robin Zhang
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
| | - Jennifer S Searle
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
| | - Xun Pei
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
| | - Xuan Li
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
| | - Hyung Don Ryoo
- Department of Cell Biology, New York University School of Medicine, New York, New York, United States of America
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Wei Du
- Ben May Department for Cancer Research, The University of Chicago, Chicago, Illinois, United States of America
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Xu H, Li H, Woo SL, Kim SM, Shende VR, Neuendorff N, Guo X, Guo T, Qi T, Pei Y, Zhao Y, Hu X, Zhao J, Chen L, Chen L, Ji JY, Alaniz RC, Earnest DJ, Wu C. Myeloid cell-specific disruption of Period1 and Period2 exacerbates diet-induced inflammation and insulin resistance. J Biol Chem 2014; 289:16374-88. [PMID: 24770415 DOI: 10.1074/jbc.m113.539601] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [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: 01/02/2023] Open
Abstract
The circadian clockworks gate macrophage inflammatory responses. Given the association between clock dysregulation and metabolic disorders, we conducted experiments to determine the extent to which over-nutrition modulates macrophage clock function and whether macrophage circadian dysregulation is a key factor linking over-nutrition to macrophage proinflammatory activation, adipose tissue inflammation, and systemic insulin resistance. Our results demonstrate that 1) macrophages from high fat diet-fed mice are marked by dysregulation of the molecular clockworks in conjunction with increased proinflammatory activation, 2) global disruption of the clock genes Period1 (Per1) and Per2 recapitulates this amplified macrophage proinflammatory activation, 3) adoptive transfer of Per1/2-disrupted bone marrow cells into wild-type mice potentiates high fat diet-induced adipose and liver tissue inflammation and systemic insulin resistance, and 4) Per1/2-disrupted macrophages similarly exacerbate inflammatory responses and decrease insulin sensitivity in co-cultured adipocytes in vitro. Furthermore, PPARγ levels are decreased in Per1/2-disrupted macrophages and PPARγ2 overexpression ameliorates Per1/2 disruption-associated macrophage proinflammatory activation, suggesting that this transcription factor may link the molecular clockworks to signaling pathways regulating macrophage polarization. Thus, macrophage circadian clock dysregulation is a key process in the physiological cascade by which diet-induced obesity triggers macrophage proinflammatory activation, adipose tissue inflammation, and insulin resistance.
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Affiliation(s)
- Hang Xu
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Honggui Li
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Shih-Lung Woo
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Sam-Moon Kim
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, Texas 77807
| | - Vikram R Shende
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, Texas 77807
| | - Nichole Neuendorff
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, Texas 77807
| | - Xin Guo
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Ting Guo
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Ting Qi
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Ya Pei
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Yan Zhao
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843
| | - Xiang Hu
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843, Department of Endocrinology and
| | - Jiajia Zhao
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843, Department of Stomatology, Union Hospital, Tongji College of Medicine, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China, and
| | - Lili Chen
- Department of Stomatology, Union Hospital, Tongji College of Medicine, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China, and
| | | | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine and
| | - Robert C Alaniz
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, College Station, Texas 77843
| | - David J Earnest
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M Health Science Center, Bryan, Texas 77807,
| | - Chaodong Wu
- From the Department of Nutrition and Food Science, Texas A&M University, College Station, Texas 77843,
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Xu W, Amire-Brahimi B, Xie XJ, Huang L, Ji JY. All-atomic molecular dynamic studies of human CDK8: insight into the A-loop, point mutations and binding with its partner CycC. Comput Biol Chem 2014; 51:1-11. [PMID: 24754906 DOI: 10.1016/j.compbiolchem.2014.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [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: 01/26/2014] [Revised: 03/23/2014] [Accepted: 03/24/2014] [Indexed: 12/31/2022]
Abstract
The Mediator, a conserved multisubunit protein complex in eukaryotic organisms, regulates gene expression by bridging sequence-specific DNA-binding transcription factors to the general RNA polymerase II machinery. In yeast, Mediator complex is organized in three core modules (head, middle and tail) and a separable 'CDK8 submodule' consisting of four subunits including Cyclin-dependent kinase CDK8 (CDK8), Cyclin C (CycC), MED12, and MED13. The 3-D structure of human CDK8-CycC complex has been recently experimentally determined. To take advantage of this structure and the improved theoretical calculation methods, we have performed molecular dynamic simulations to study dynamics of CDK8 and two CDK8 point mutations (D173A and D189N), which have been identified in human cancers, with and without full length of the A-loop, as well as the binding between CDK8 and CycC. We found that CDK8 structure gradually loses two helical structures during the 50-ns molecular dynamic simulation, likely due to the presence of the full-length A-loop. In addition, our studies showed the hydrogen bond occupation of the CDK8 A-loop increases during the first 20-ns MD simulation and stays stable during the later 30-ns MD simulation. Four residues in the A-loop of CDK8 have high hydrogen bond occupation, while the rest residues have low or no hydrogen bond occupation. The hydrogen bond dynamic study of the A-loop residues exhibits three types of changes: increasing, decreasing, and stable. Furthermore, the 3-D structures of CDK8 point mutations D173A, D189N, T196A and T196D have been built by molecular modeling and further investigated by 50-ns molecular dynamic simulations. D173A has the highest average potential energy, while T196D has the lowest average potential energy, indicating that T196D is the most stable structure. Finally, we calculated theoretical binding energy of CDK8 and CycC by MM/PBSA and MM/GBSA methods, and the negative values obtained from both methods demonstrate stability of CDK8-CycC complex. Taken together, these analyses will improve our understanding of the exact functions of CDK8 and the interaction with its partner CycC.
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Affiliation(s)
- Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA.
| | - Benjamin Amire-Brahimi
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA
| | - Xiao-Jun Xie
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA
| | - Liying Huang
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, TX 77843, USA.
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Ji JY, Xing YJ, Ma ZT, Zhang M, Zheng P. Acute toxicity of pharmaceutical wastewaters containing antibiotics to anaerobic digestion treatment. Chemosphere 2013; 91:1094-1098. [PMID: 23415489 DOI: 10.1016/j.chemosphere.2013.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 06/01/2023]
Abstract
In the present study, a method for prediction of the toxicity of pharmaceutical wastewaters containing antibiotics to microbial communities in anaerobic digestion treatment was developed. Luminescent bacterium assay was carried out with Vibrio fischeri as indicator. The individual and joint toxicities of antibiotics and anaerobic digestion metabolites were investigated by using the 15-min half inhibitory concentration (15 min-IC50) at pH 7.00±0.05. The results showed that the 15 min-IC50 of Amoxicillin, Kanamycin, Lincomycin and Ciprofloxacin were 3.99, 5.11, 4.32 and 5.63 g L(-1) respectively, and the toxicity descended in the order of Amoxicillin, Lincomycin, Kanamycin and Ciprofloxacin. Using equitoxic ratio mixing method, the joint toxicities of four anaerobic digestion intermediates, the four intermediates together with Amoxicillin, Ciprofloxacin, Kanamycin or Lincomycin were determined, which displayed that their interactions were additive, additive, synergistic, synergistic and synergistic respectively. Finally the joint effect of all intermediates and antibiotics was synergistic. The method has promising applications in evaluating the joint toxicity of anaerobic digestion intermediates and antibiotics, and has laid the foundations for assessing the feasibility of anaerobic treatment of pharmaceutical wastewater containing antibiotics.
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Affiliation(s)
- Jun-Yuan Ji
- Department of Environmental Engineering, Zhejiang University, Hangzhou, China
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28
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Gu W, Wang C, Li W, Hsu FN, Tian L, Zhou J, Yuan C, Xie XJ, Jiang T, Addya S, Tai Y, Kong B, Ji JY. Tumor-suppressive effects of CDK8 in endometrial cancer cells. Cell Cycle 2013; 12:987-99. [PMID: 23454913 DOI: 10.4161/cc.24003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
CDK8 is either amplified or mutated in a variety of human cancers, and CDK8 functions as an oncoprotein in melanoma and colorectal cancers. Previously, we reported that loss or reduction of CDK8 results in aberrant fat accumulation in Drosophila and mammals, suggesting that CDK8 plays an important role in inhibiting lipogenesis. Epidemiological studies have identified obesity and overweight as the major risk factors of endometrial cancer, thus we examined whether CDK8 regulates endometrial cancer cell growth by using several endometrial cancer cell lines, including KLE, which express low levels of CDK8, as well as AN3 CA and HEC-1A cells, which have high levels of endogenous CDK8. We observed that ectopic expression of CDK8 in KLE cells inhibited cell proliferation and potently blocked tumor growth in an in vivo mouse model. In addition, gain of CDK8 in KLE cells blocked cell migration and invasion in transwell, wound healing and persistence of migratory directionality assays. Conversely, we observed the opposite effects in all of the aforementioned assays when CDK8 was depleted in AN3 CA cells. Similar to AN3 CA cells, depletion of CDK8 in HEC-1A cells strongly enhanced cell migration in transwell assays, while overexpression of CDK8 in HEC-1A cells blocked cell migration. Furthermore, gene profiling of KLE cells overexpressing CDK8 revealed genes whose protein products are involved in lipid metabolism, cell cycle and cell movement pathways. Finally, depletion of CDK8 increased the expression of lipogenic genes in endometrial cancer cells. Taken together, these results show a reverse correlation between CDK8 levels and several key features of the endometrial cancer cells, including cell proliferation, migration and invasion as well as tumor formation in vivo. Therefore, in contrast to the oncogenic effects of CDK8 in melanoma and colorectal cancers, our results suggest that CDK8 plays a tumor-suppressive role in endometrial cancers.
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Affiliation(s)
- Weiting Gu
- Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Jinan, Shandong, China
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29
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Ji JY, Xing YJ, Ma ZT, Cai J, Zheng P, Lu HF. Toxicity assessment of anaerobic digestion intermediates and antibiotics in pharmaceutical wastewater by luminescent bacterium. J Hazard Mater 2013; 246-247:319-323. [PMID: 23334482 DOI: 10.1016/j.jhazmat.2012.12.025] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 10/30/2012] [Accepted: 12/12/2012] [Indexed: 06/01/2023]
Abstract
In order to evaluate the effect of anaerobic digestion intermediates and antibiotics in pharmaceutical wastewaters on anaerobic digestion process, their acute toxicities were tested using the 15 min median inhibitory concentration (IC(50)) at pH 7.00 ± 0.05. The results showed that the IC(50) of ethanol, acetate, propionate and butyrate were 19.40, 20.71, 10.47 and 12.17 g L(-1) respectively, which suggested the toxicity descended in the order of propionate, butyrate, ethanol and acetate. The IC(50) of aureomycin, polymyxin and chloromycetin were 12.06, 6.24 and 429.90 mg L(-1) respectively, which indicated the toxicity descended in the order of polymyxin, aureomycin and chloromycetin. Using equitoxic ratio mixing method, the joint toxicities of five groups referred by A (four anaerobic digestion intermediates), B (four anaerobic digestion intermediates and aureomycin), C (four anaerobic digestion intermediates and polymyxin), D (four anaerobic digestion intermediates and chloromycetin) and E (four anaerobic digestion intermediates, aureomycin, polymyxin and chloromycetin) were investigated respectively. Their interactions were additive (A), synergistic (B), additive (C), synergistic (D) and synergistic (E). The investigation would lay a basis for the optimization of anaerobic biotechnology for pharmaceutical wastewater treatment.
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Affiliation(s)
- Jun-Yuan Ji
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
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30
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Ji JY, Xing YJ, Zheng P. [Acute toxicity of antibiotics and anaerobic digestion intermediates in pharmaceutical wastewaters]. Huan Jing Ke Xue 2012; 33:4367-4372. [PMID: 23379166] [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] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In order to determine the toxicity of antibiotics and anaerobic digestion intermediates on anaerobic treatment of pharmaceutical wastewaters containing antibiotics, the single and joint toxicities of some antibiotics and intermediates to Photobacterium phosphoreum were tested by using the 15-min half inhibitory concentration (15 min-IC50) at pH = 7.00 +/- 0.05. The results showed that the 15 min-IC50 of ethanol, acetate, propionate and butyrate were 19.40, 20.71, 10.47 and 12.17 g x L(-1), respectively, which indicated that the toxicity descended in the order of propionate, butyrate, ethanol and acetate. The 15 min-IC50 of Amoxicillin, Kanamycin, Lincomycin and Ciprofloxacin were 3.99, 5.11, 4.32 and 5.63 g x L(-1), respectively, so the toxicity descended in the order of Amoxicillin, Lincomycin, Kanamycin and Ciprofloxacin. Using equal effect mixing method, the joint toxicity of four anaerobic digestion intermediates, the four intermediates together with Amoxicillin, Ciprofloxacin, Kanamycin, Lincomycin individually and all together were investigated, which demonstrated that the first three interactions were additive and the last three were synergistic. The observations have laid a foundation for control and optimization of anaerobic biotechnology for pharmaceutical wastewater containing antibiotics.
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Affiliation(s)
- Jun-Yuan Ji
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
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31
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Lu HF, Zheng P, Ji QX, Zhang HT, Ji JY, Wang L, Ding S, Chen TT, Zhang JQ, Tang CJ, Chen JW. The structure, density and settlability of anammox granular sludge in high-rate reactors. Bioresour Technol 2012; 123:312-317. [PMID: 22940335 DOI: 10.1016/j.biortech.2012.07.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/30/2012] [Accepted: 07/04/2012] [Indexed: 06/01/2023]
Abstract
Microscopic observation and settling test were carried out to investigate the structure, density and settlability of anammox granules taken from a high-rate upflow anaerobic sludge blanket (UASB) reactor. The results showed that the anammox granules were irregular in shape and uneven on surface, and their structure included granule, subunit, microbial cell cluster and single cell. The gas pockets were often observed in the anammox granules, and they originated from the obstruction of gas tunnel by extracellular polymer substances (EPSs) and the inflation of produced dinitrogen gas. The volume of gas pockets became larger with the increasing diameter of anammox granules, which led to the decreasing density and the floatation of anammox granules. The diameter of anammox granules should be controlled at less than 2.20mm to avoid the granule floatation. A hypothesized mechanism for the granulation and floatation of anammox biomass was proposed.
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Affiliation(s)
- Hui-Feng Lu
- Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China
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Herr A, Longworth M, Ji JY, Korenjak M, Macalpine DM, Dyson NJ. Identification of E2F target genes that are rate limiting for dE2F1-dependent cell proliferation. Dev Dyn 2012; 241:1695-707. [PMID: 22972499 DOI: 10.1002/dvdy.23857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2012] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Microarray studies have shown that the E2F transcription factor influences the expression of many genes but it is unclear how many of these targets are important for E2F-mediated control of cell proliferation. RESULTS We assembled a collection of mutant alleles of 44 dE2F1-dependent genes and tested whether these could modify visible phenotypes caused by the tissue-specific depletion of dE2F1. More than half of the mutant alleles dominantly enhanced de2f1-dsRNA phenotypes suggesting that the in vivo functions of dE2F1 can be limited by the reduction in the level of expression of many different targets. Unexpectedly, several mutant alleles suppressed de2f1-dsRNA phenotypes. One of the strongest of these suppressors was Orc5. Depletion of ORC5 increased proliferation in cells with reduced dE2F1 and specifically elevated the expression of dE2F1-regulated genes. Importantly, these effects were independent of dE2F1 protein levels, suggesting that reducing the level of ORC5 did not interfere with the general targeting of dE2F1. CONCLUSIONS We propose that the interaction between ORC5 and dE2F1 may reflect a feedback mechanism between replication initiation proteins and dE2F1 that ensures that proliferating cells maintain a robust level of replication proteins for the next cell cycle.
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Affiliation(s)
- Anabel Herr
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Laboratory of Molecular Oncology, Charlestown, MA 02129, USA
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33
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Li W, Tai Y, Zhou J, Gu W, Bai Z, Zhou T, Zhong Z, McCue PA, Sang N, Ji JY, Kong B, Jiang J, Wang C. Repression of endometrial tumor growth by targeting SREBP1 and lipogenesis. Cell Cycle 2012; 11:2348-58. [PMID: 22672904 DOI: 10.4161/cc.20811] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The aberrantly increased lipogenesis is a universal metabolic feature of proliferating tumor cells. Although most normal cells acquire the bulk of their fatty acids from circulation, tumor cells synthesize more than 90% of required lipids de novo. The sterol regulatory element-binding protein 1 (SREBP1), encoded by SREBF1 gene, is a master regulator of lipogenic gene expression. SREBP1 and its target genes are overexpressed in a variety of cancers; however, the role of SREBP1 in endometrial cancer is largely unknown. We have screened a cohort of endometrial cancer (EC) specimen for their lipogenic gene expression and observed a significant increase of SREBP1 target gene expression in cancer cells compared with normal endometrium. By using immunohistochemical staining, we confirmed SREBP1 protein overexpression and demonstrated increased nuclear distribution of SREBP1 in EC. In addition, we found that knockdown of SREBP1 expression in EC cells suppressed cell growth, reduced colonigenic capacity and slowed tumor growth in vivo. Furthermore, we observed that knockdown of SREBP1 induced significant cell death in cultured EC cells. Taken together, our results show that SREBP1 is essential for EC cell growth both in vitro and in vivo, suggesting that SREBP1 activity may be a novel therapeutic target for endometrial cancers.
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Affiliation(s)
- Weihua Li
- Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Jinan, Shandong, China
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Zhao X, Feng D, Wang Q, Abdulla A, Xie XJ, Zhou J, Sun Y, Yang ES, Liu LP, Vaitheesvaran B, Bridges L, Kurland IJ, Strich R, Ni JQ, Wang C, Ericsson J, Pessin JE, Ji JY, Yang F. Regulation of lipogenesis by cyclin-dependent kinase 8-mediated control of SREBP-1. J Clin Invest 2012; 122:2417-27. [PMID: 22684109 DOI: 10.1172/jci61462] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 05/02/2012] [Indexed: 01/09/2023] Open
Abstract
Altered lipid metabolism underlies several major human diseases, including obesity and type 2 diabetes. However, lipid metabolism pathophysiology remains poorly understood at the molecular level. Insulin is the primary stimulator of hepatic lipogenesis through activation of the SREBP-1c transcription factor. Here we identified cyclin-dependent kinase 8 (CDK8) and its regulatory partner cyclin C (CycC) as negative regulators of the lipogenic pathway in Drosophila, mammalian hepatocytes, and mouse liver. The inhibitory effect of CDK8 and CycC on de novo lipogenesis was mediated through CDK8 phosphorylation of nuclear SREBP-1c at a conserved threonine residue. Phosphorylation by CDK8 enhanced SREBP-1c ubiquitination and protein degradation. Importantly, consistent with the physiologic regulation of lipid biosynthesis, CDK8 and CycC proteins were rapidly downregulated by feeding and insulin, resulting in decreased SREBP-1c phosphorylation. Moreover, overexpression of CycC efficiently suppressed insulin and feeding-induced lipogenic gene expression. Taken together, these results demonstrate that CDK8 and CycC function as evolutionarily conserved components of the insulin signaling pathway in regulating lipid homeostasis.
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Affiliation(s)
- Xiaoping Zhao
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, NY, USA
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35
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Abstract
E2F transcription factors are important regulators of cell proliferation and are frequently dysregulated in human malignancies. To identify novel regulators of E2F function, we used Drosophila as a model system to screen for mutations that modify phenotypes caused by reduced levels of dE2F1. This screen identified components of the Pumilio translational repressor complex (Pumilio, Nanos, and Brain tumor) as suppressors of dE2F1-RNAi phenotypes. Subsequent experiments provided evidence that Pumilio complexes repress dE2F1 levels and that this mechanism of post-transcriptional regulation is conserved in human cells. The human Pumilio homologs Pum 1 and Pum 2 repress the translation of E2F3 by binding to the E2F3 3' untranslated region (UTR) and also enhance the activity of multiple E2F3 targeting microRNAs (miRNAs). E2F3 is an oncogene with strong proliferative potential and is regularly dysregulated or overexpressed in cancer. Interestingly, Pumilio/miRNA-mediated regulation of E2F3 is circumvented in cancer cells in several different ways. Bladder carcinomas selectively down-regulate miRNAs that cooperate with Pumilio to target E2F3, and multiple tumor cell lines shorten the 3' end of the E2F3 mRNA, removing the Pumilio regulatory elements. These studies suggest that Pumilio-miRNA repression of E2F3 translation provides an important level of E2F regulation that is frequently abrogated in cancer cells.
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Affiliation(s)
- Wayne O Miles
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Harvard Medical School, Charlestown, 02129, USA
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36
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Abstract
Appropriately controlled gene expression is fundamental for normal growth and survival of all living organisms. In eukaryotes, the transcription of protein-coding mRNAs is dependent on RNA polymerase II (Pol II). The multi-subunit transcription cofactor Mediator complex is proposed to regulate most, if not all, of the Pol II-dependent transcription. Here we focus our discussion on two subunits of the Mediator complex, cyclin-dependent kinase 8 (CDK8) and its regulatory partner Cyclin C (CycC), because they are either mutated or amplified in a variety of human cancers. CDK8 functions as an oncoprotein in melanoma and colorectal cancers, thus there are considerable interests in developing drugs specifically targeting the CDK8 kinase activity. However, to evaluate the feasibility of targeting CDK8 for cancer therapy and to understand how their dysregulation contributes to tumorigenesis, it is essential to elucidate the in vivo function and regulation of CDK8-CycC, which are still poorly understood in multi-cellular organisms. We summarize the evidence linking their dysregulation to various cancers and present our bioinformatics and computational analyses on the structure and evolution of CDK8. We also discuss the implications of these observations in tumorigenesis. Because most of the Mediator subunits, including CDK8 and CycC, are highly conserved during eukaryotic evolution, we expect that investigations using model organisms such as Drosophila will provide important insights into the function and regulation of CDK8 and CycC in different cellular and developmental contexts.
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Affiliation(s)
- Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA
- Corresponding author: Tel: +1 979 845 6389, fax: +1 979 847 9481. (J.-Y. Ji)
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37
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Mulligan P, Yang F, Di Stefano L, Ji JY, Ouyang J, Nishikawa JL, Toiber D, Kulkarni M, Wang Q, Najafi-Shoushtari SH, Mostoslavsky R, Gygi SP, Gill G, Dyson NJ, Näär AM. A SIRT1-LSD1 corepressor complex regulates Notch target gene expression and development. Mol Cell 2011; 42:689-99. [PMID: 21596603 DOI: 10.1016/j.molcel.2011.04.020] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 03/30/2011] [Accepted: 04/22/2011] [Indexed: 01/28/2023]
Abstract
Epigenetic regulation of gene expression by histone-modifying corepressor complexes is central to normal animal development. The NAD(+)-dependent deacetylase and gene repressor SIRT1 removes histone H4K16 acetylation marks and facilitates heterochromatin formation. However, the mechanistic contribution of SIRT1 to epigenetic regulation at euchromatic loci and whether it acts in concert with other chromatin-modifying activities to control developmental gene expression programs remain unclear. We describe here a SIRT1 corepressor complex containing the histone H3K4 demethylase LSD1/KDM1A and several other LSD1-associated proteins. SIRT1 and LSD1 interact directly and play conserved and concerted roles in H4K16 deacetylation and H3K4 demethylation to repress genes regulated by the Notch signaling pathway. Mutations in Drosophila SIRT1 and LSD1 orthologs result in similar developmental phenotypes and genetically interact with the Notch pathway in Drosophila. These findings offer new insights into conserved mechanisms of epigenetic gene repression and regulation of development by SIRT1 in metazoans.
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Affiliation(s)
- Peter Mulligan
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA
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38
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Walker AK, Yang F, Jiang K, Ji JY, Watts JL, Purushotham A, Boss O, Hirsch ML, Ribich S, Smith JJ, Israelian K, Westphal CH, Rodgers JT, Shioda T, Elson SL, Mulligan P, Najafi-Shoushtari H, Black JC, Thakur JK, Kadyk LC, Whetstine JR, Mostoslavsky R, Puigserver P, Li X, Dyson NJ, Hart AC, Näär AM. Conserved role of SIRT1 orthologs in fasting-dependent inhibition of the lipid/cholesterol regulator SREBP. Genes Dev 2010; 24:1403-17. [PMID: 20595232 DOI: 10.1101/gad.1901210] [Citation(s) in RCA: 270] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The sterol regulatory element-binding protein (SREBP) transcription factor family is a critical regulator of lipid and sterol homeostasis in eukaryotes. In mammals, SREBPs are highly active in the fed state to promote the expression of lipogenic and cholesterogenic genes and facilitate fat storage. During fasting, SREBP-dependent lipid/cholesterol synthesis is rapidly diminished in the mouse liver; however, the mechanism has remained incompletely understood. Moreover, the evolutionary conservation of fasting regulation of SREBP-dependent programs of gene expression and control of lipid homeostasis has been unclear. We demonstrate here a conserved role for orthologs of the NAD(+)-dependent deacetylase SIRT1 in metazoans in down-regulation of SREBP orthologs during fasting, resulting in inhibition of lipid synthesis and fat storage. Our data reveal that SIRT1 can directly deacetylate SREBP, and modulation of SIRT1 activity results in changes in SREBP ubiquitination, protein stability, and target gene expression. In addition, chemical activators of SIRT1 inhibit SREBP target gene expression in vitro and in vivo, correlating with decreased hepatic lipid and cholesterol levels and attenuated liver steatosis in diet-induced and genetically obese mice. We conclude that SIRT1 orthologs play a critical role in controlling SREBP-dependent gene regulation governing lipid/cholesterol homeostasis in metazoans in response to fasting cues. These findings may have important biomedical implications for the treatment of metabolic disorders associated with aberrant lipid/cholesterol homeostasis, including metabolic syndrome and atherosclerosis.
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Affiliation(s)
- Amy K Walker
- Massachusetts General Hospital Cancer Center, Charlestown, Massachusetts 02129, USA
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Zhang J, Ji JY, Yi M, Overholtzer M, Smolen GA, Wang R, Brugge JS, Dyson NJ, Haber DA. Abstract LB-228: YAP-dependent induction of amphiregulin identifies a non-cell-autonomous component of the Hippo pathway. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-lb-228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The Hippo signaling pathway was initially identified in Drosophila and components in this pathway are highly conserved in mammals. We and others have recently shown that the Hippo pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. The pivotal effector of this pathway is YAP, a transcriptional co-activator amplified in mouse and human cancers, where it promotes epithelial to mesenchymal transition (EMT) and malignant transformation. To date, studies of YAP target genes have focused on cell-autonomous mediators. Here, we show that YAP-expressing MCF10A breast epithelial cells secrete growth factors that enhance the proliferation of neighboring untransfected cells, implicating a non-cell autonomous mechanism. Using cytokine and growth factor array analysis, we identified the epidermal growth factor receptor (EGFR) ligand, amphiregulin (AREG), as a transcriptional target of YAP, whose induction contributes to YAP-mediated cell proliferation and migration. Knockdown of AREG or addition of an EGFR kinase inhibitor abrogates the proliferative effects of YAP expression. Suppression of the negative YAP regulators LATS1/2 is sufficient to induce AREG expression, consistent with a physiological regulation of AREG by the Hippo pathway. Furthermore, genetic interactions between the Drosophila YAP orthologue Yki and Egfr signaling components support the link between these two highly conserved signaling pathways. In conclusion, YAP-dependent secretion of AREG implicates activation of EGFR signaling as an important non-cell autonomous effector of the Hippo pathway, with relevance for the regulation of both physiological and malignant cell proliferation.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-228.
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Affiliation(s)
| | - Jun-Yuan Ji
- 2Texas A & M Health Science Center, College Station, TX
| | - Min Yi
- 1Massachusetts General Hospital, Charlestown, MA
| | | | | | - Rececca Wang
- 1Massachusetts General Hospital, Charlestown, MA
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40
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Zhang J, Ji JY, Yu M, Overholtzer M, Smolen GA, Brugge JS, Dyson NJ, Haber DA. Abstract A12: YAP-dependent induction of amphiregulin identifies a non-cell-autonomous component of the Hippo pathway. Cancer Res 2009. [DOI: 10.1158/0008-5472.fbcr09-a12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The Hippo signaling pathway was initially identified in Drosophila and components in this pathway are highly conserved in mammals. We and others have recently shown that the Hippo pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. The pivotal effector of this pathway is YAP, a transcriptional co-activator amplified in mouse and human cancers, where it promotes epithelial to mesenchymal transition (EMT) and malignant transformation. To date, studies of YAP target genes have focused on cellautonomous mediators. Here, we show that YAP-expressing MCF10A breast epithelial cells secrete growth factors that enhance the proliferation of neighboring untransfected cells, implicating a non-cell autonomous mechanism. Using cytokine and growth factor array analysis, we identified the epidermal growth factor receptor (EGFR) ligand, amphiregulin (AREG), as a transcriptional target of YAP, whose induction contributes to YAP-mediated cell proliferation and migration. Knockdown of AREG or addition of an EGFR kinase inhibitor abrogates the proliferative effects of YAP expression. Suppression of the negative YAP regulators LATS1/2 is sufficient to induce AREG expression, consistent with a physiological regulation of AREG by the Hippo pathway. Furthermore, genetic interactions between the Drosophila YAP orthologue Yki and Egfr signaling components support the link between these two highly conserved signaling pathways. In conclusion, YAP-dependent secretion of AREG implicates activation of EGFR signaling as an important non-cell autonomous effector of the Hippo pathway, with relevance for the regulation of both physiological and malignant cell proliferation.
Citation Information: Cancer Res 2009;69(23 Suppl):A12.
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Affiliation(s)
| | - Jun-Yuan Ji
- 1 Massachusetts General Hospital, Charlestown, MA,
| | - Min Yu
- 1 Massachusetts General Hospital, Charlestown, MA,
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Zhang J, Ji JY, Yu M, Overholtzer M, Smolen GA, Wang R, Brugge JS, Dyson NJ, Haber DA. YAP-dependent induction of amphiregulin identifies a non-cell-autonomous component of the Hippo pathway. Nat Cell Biol 2009; 11:1444-50. [PMID: 19935651 DOI: 10.1038/ncb1993] [Citation(s) in RCA: 325] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Accepted: 08/12/2009] [Indexed: 01/03/2023]
Abstract
The Hippo signalling pathway regulates cellular proliferation and survival, thus has profound effects on normal cell fate and tumorigenesis. The pivotal effector of this pathway is YAP (yes-associated protein), a transcriptional co-activator amplified in mouse and human cancers, where it promotes epithelial to mesenchymal transition (EMT) and malignant transformation. So far, studies of YAP target genes have focused on cell-autonomous mediators; here we show that YAP-expressing MCF10A breast epithelial cells enhance the proliferation of neighbouring untransfected cells, implicating a non-cell-autonomous mechanism. We identify the gene for the epidermal growth factor receptor (EGFR) ligand amphiregulin (AREG) as a transcriptional target of YAP, whose induction contributes to YAP-mediated cell proliferation and migration, but not EMT. Knockdown of AREG or addition of an EGFR kinase inhibitor abrogates the proliferative effects of YAP expression. Suppression of the negative YAP regulators LATS1 and 2 (large tumour suppressor 1 and 2) is sufficient to induce AREG expression, consistent with physiological regulation of AREG by the Hippo pathway. Genetic interaction between the Drosophila YAP orthologue Yorkie and Egfr signalling components supports the link between these two highly conserved signalling pathways. Thus, YAP-dependent secretion of AREG indicates that activation of EGFR signalling is an important non-cell-autonomous effector of the Hippo pathway, which has implications for the regulation of both physiological and malignant cell proliferation.
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Affiliation(s)
- Jianmin Zhang
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Charlestown, MA 02129, USA
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42
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Longworth MS, Herr A, Ji JY, Dyson NJ. RBF1 promotes chromatin condensation through a conserved interaction with the Condensin II protein dCAP-D3. Genes Dev 2008; 22:1011-24. [PMID: 18367646 DOI: 10.1101/gad.1631508] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Drosophila retinoblastoma family of proteins (RBF1 and RBF2) and their mammalian homologs (pRB, p130, and p107) are best known for their regulation of the G1/S transition via the repression of E2F-dependent transcription. However, RB family members also possess additional functions. Here, we report that rbf1 mutant larvae have extensive defects in chromatin condensation during mitosis. We describe a novel interaction between RBF1 and dCAP-D3, a non-SMC component of the Condensin II complex that links RBF1 to the regulation of chromosome structure. RBF1 physically interacts with dCAP-D3, RBF1 and dCAP-D3 partially colocalize on polytene chromosomes, and RBF1 is required for efficient association of dCAP-D3 with chromatin. dCap-D3 mutants also exhibit chromatin condensation defects, and mutant alleles of dCap-D3 suppress cellular and developmental phenotypes induced by the overexpression of RBF1. Interestingly, this interaction is conserved between flies and humans. The re-expression of pRB into a pRB-deficient human tumor cell line promotes chromatin association of hCAP-D3 in a manner that depends on the LXCXE-binding cleft of pRB. These results uncover an unexpected link between pRB/RBF1 and chromatin condensation, providing a mechanism by which the functional inactivation of RB family members in human tumor cells may contribute to genome instability.
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Affiliation(s)
- Michelle S Longworth
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129, USA
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43
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Di Stefano L, Ji JY, Moon NS, Herr A, Dyson N. Mutation of Drosophila Lsd1 disrupts H3-K4 methylation, resulting in tissue-specific defects during development. Curr Biol 2007; 17:808-12. [PMID: 17462898 PMCID: PMC1909692 DOI: 10.1016/j.cub.2007.03.068] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 03/29/2007] [Accepted: 03/30/2007] [Indexed: 11/30/2022]
Abstract
Histone-tail modifications play a fundamental role in the processes that establish chromatin structure and determine gene expression. One such modification, histone methylation, was considered irreversible until the recent discovery of histone demethylases. Lsd1 was the first histone demethylase to be identified. Lsd1 is highly conserved in many species, from yeast to humans, but its function has primarily been studied through biochemical approaches. The mammalian ortholog has been shown to demethylate monomethyl- and dimethyl-K4 and -K9 residues of histone H3. Here we describe the effects of Lsd1 mutation in Drosophila. The inactivation of dLsd1 strongly affects the global level of monomethyl- and dimethyl-H3-K4 methylation and results in elevated expression of a subset of genes. dLsd1 is not an essential gene, but animal viability is strongly reduced in mutant animals in a gender-specific manner. Interestingly, dLsd1 mutants are sterile and possess defects in ovary development, indicating that dLsd1 has tissue-specific functions. Mutant alleles of dLsd1 suppress positional-effect variegation, suggesting a disruption of the balance between euchromatin and heterochromatin. Taken together, these results show that dLsd1-mediated H3-K4 demethylation has a significant and specific role in Drosophila development.
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Affiliation(s)
| | | | | | | | - Nicholas Dyson
- *Corresponding author: Nicholas Dyson, , Fax: +1-617-726-7808, Tel: +1-617-726-7800
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Morris EJ, Michaud WA, Ji JY, Moon NS, Rocco JW, Dyson NJ. Functional identification of Api5 as a suppressor of E2F-dependent apoptosis in vivo. PLoS Genet 2006; 2:e196. [PMID: 17112319 PMCID: PMC1636698 DOI: 10.1371/journal.pgen.0020196] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Accepted: 10/03/2006] [Indexed: 11/24/2022] Open
Abstract
Retinoblastoma protein and E2-promoter binding factor (E2F) family members are important regulators of G1-S phase progression. Deregulated E2F also sensitizes cells to apoptosis, but this aspect of E2F function is poorly understood. Studies of E2F-induced apoptosis have mostly been carried out in tissue culture cells, and the analysis of the factors that are important for this process has been restricted to the testing of a few candidate genes. Using Drosophila as a model system, we have generated tools that allow genetic modifiers of E2F-dependent apoptosis to be identified in vivo and developed assays that allow effects on E2F-induced apoptosis to be studied in cultured cells. Genetic interactions show that dE2F1-dependent apoptosis in vivo involves dArk/Apaf1 apoptosome-dependent activation of both initiator and effector caspases and is sensitive to levels of Drosophila inhibitor of apoptosis-1 (dIAP1). Using these approaches, we report the surprising finding that apoptosis inhibitor-5/antiapoptosis clone-11 (Api5/Aac11) is a critical determinant of dE2F1-induced apoptosis in vivo and in vitro. This functional interaction occurs in multiple tissues, is specific to E2F-induced apoptosis, and is conserved from flies to humans. Interestingly, Api5/Aac11 acts downstream of E2F and suppresses E2F-dependent apoptosis without generally blocking E2F-dependent transcription. Api5/Aac11 expression is often upregulated in tumor cells, particularly in metastatic cells. We find that depletion of Api5 is tumor cell lethal. The strong genetic interaction between E2F and Api5/Aac11 suggests that elevated levels of Api5 may be selected during tumorigenesis to allow cells with deregulated E2F activity to survive under suboptimal conditions. Therefore, inhibition of Api5 function might offer a possible mechanism for antitumor exploitation. The retinoblastoma protein (pRB) was the first human tumor suppressor to be described, and it works by limiting the activity of the E2F transcription factor. The pRB pathway is inactivated in most forms of cancer, and, accordingly, most tumor cells have deregulated E2F. Uncontrolled E2F drives cell proliferation, but it also sensitizes cells to die (apoptosis). E2F-induced apoptosis is not well understood, but it affects the development of cancer and, potentially, could be exploited for cancer treatment. To date, however, there have been very few studies of E2F-induced apoptosis in animal models. The authors describe a series of genetic tools that allow systematic studies of E2F-induced apoptosis in Drosophila. As validation, this approach identified some known regulators of E2F-dependent apoptosis and also identified Api5, a little-studied gene that had not previously been linked to E2F, as a potent suppressor of E2F-induced cell death. The effects of Api5 on E2F occur in several different tissues and are conserved from flies to humans. This last point is significant since Api5 is upregulated in cancer cells. The discovery of the E2F–Api5 interaction demonstrates that important modulators of E2F-induced apoptosis are waiting to be discovered and that they can be found using Drosophila.
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Affiliation(s)
- Erick J Morris
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - William A Michaud
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Surgical Oncology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States of America
| | - Jun-Yuan Ji
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Nam-Sung Moon
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - James W Rocco
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Surgical Oncology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States of America
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Charlestown, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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Abstract
The Drosophila embryo is a promising model for isolating gene products that coordinate S phase and mitosis. We have reported before that increasing maternal Cyclin B dosage to up to six copies (six cycB) increases Cdk1-Cyclin B (CycB) levels and activity in the embryo, delays nuclear migration at cycle 10, and produces abnormal nuclei at cycle 14. Here we show that the level of CycB in the embryo inversely correlates with the ability to lengthen interphase as the embryo transits from preblastoderm to blastoderm stages and defines the onset of a checkpoint that regulates mitosis when DNA replication is blocked with aphidicolin. A screen for modifiers of the six cycB phenotypes identified 10 new suppressor deficiencies. In addition, heterozygote dRPA2 (a DNA replication gene) mutants suppressed only the abnormal nuclear phenotype at cycle 14. Reduction of dRPA2 also restored interphase duration and checkpoint efficacy to control levels. We propose that lowered dRPA2 levels activate Grp/Chk1 to counteract excess Cdk1-CycB activity and restore interphase duration and the ability to block mitosis in response to aphidicolin. Our results suggest an antagonistic interaction between DNA replication checkpoint activation and Cdk1-CycB activity during the transition from preblastoderm to blastoderm cycles.
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Affiliation(s)
- Justin Crest
- Department of Biology, University of Washington, Seattle, Washington 98195-1800, USA.
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Stevaux O, Dimova DK, Ji JY, Moon NS, Frolov MV, Dyson NJ. Retinoblastoma family 2 is required in vivo for the tissue-specific repression of dE2F2 target genes. Cell Cycle 2005; 4:1272-80. [PMID: 16082225 DOI: 10.4161/cc.4.9.1982] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [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] [Indexed: 11/19/2022] Open
Abstract
In higher eukaryotes, the Retinoblastoma and E2F families of proteins control the transcription of a large number of target genes. Here, we have mutated the second Drosophila Retinoblastoma family gene (Rbf2), and contrasted the in vivo molecular functions of RBF2 with dE2F2, the only E2F partner of RBF2. Previous studies failed to uncover a unique role for RBF2 in E2F regulation. Here we find that RBF2 functions in concert with dE2F2 in vivo to repress the expression of differentiation markers in ovaries and embryos where RBF2 is highly expressed. We have compared the profiles of transcripts that are mis-expressed in ovaries, embryos and S2 cells where RBF2 function has been ablated and find that RBF2 and dE2F2 control strikingly different transcriptional programs in each situation. In vivo promoter occupancy studies point to the redistribution of dE2F/RBF complexes to different promoters in different cell types as one mechanism governing the tissue-specific regulation of dE2F/RBF target genes. These results demonstrate that RBF2 has a unique function in repressing E2F-regulated differentiation markers and that dE2F2 and RBF2 are required to regulate different sets of target genes in different tissues.
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Affiliation(s)
- Olivier Stevaux
- Massachusetts General Hospital Cancer Center, Charlestown, Massachusetts 02129, USA
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47
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Abstract
Cdk1-CycB plays a key role in regulating many aspects of cell-cycle events, such as cytoskeletal dynamics and chromosome behavior during mitosis. To investigate how Cdk1-CycB controls the coordination of these events, we performed a dosage-sensitive genetic screen, which is based on the observations that increased maternal CycB (four extra gene copies) leads to higher Cdk1-CycB activity in early Drosophila embryos, delays anaphase onset, and generates a sensitized non-lethal phenotype at the blastoderm stage (defined as six cycB phenotype). Here, we report that mutations in the gene three rows (thr) enhance, while mutations in pimples (pim, encoding Drosophila Securin) or separase (Sse) suppress, the sensitized phenotype. In Drosophila, both Pim and Thr are known to regulate Sse activity, and activated Sse cleaves a Cohesin subunit to initiate anaphase. Compared with the six cycB embryos, reducing Thr in embryos with more CycB further delays the initiation of anaphase, whereas reducing either Pim or Sse has the opposite effect. Furthermore, nuclei move slower during cortical migration in embryos with higher Cdk1-CycB activity, whereas reducing either Pim or Sse suppresses this phenotype by causing a novel nuclear migration pattern. Therefore, our genetic screen has identified all three components of the complex that regulates sister chromatid separation, and our observations indicate that interactions between Cdk1-CycB and the Pim-Thr-Sse complex are dosage sensitive.
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Affiliation(s)
- Jun-Yuan Ji
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA.
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Abstract
The earliest embryonic mitoses in Drosophila, as in other animals except mammals, are viewed as synchronous and of equal duration. However, we observed that total cell-cycle length steadily increases after cycle 7, solely owing to the extension of interphase. Between cycle 7 and cycle 10, this extension is DNA-replication checkpoint independent, but correlates with the onset of Cyclin B oscillation. In addition, nuclei in the middle of embryos have longer metaphase and shorter anaphase than nuclei at the two polar regions. Interestingly, sister chromatids move faster in anaphase in the middle than the posterior region. These regional differences correlate with local differences in Cyclin B concentration. After cycle 10, interphase and total cycle duration of nuclei in the middle of the embryo are longer than at the poles. Because interphase also extends in checkpoint mutant (grapes) embryo after cycle 10, although less dramatic than wild-type embryos, interphase extension after cycle 10 is probably controlled by both Cyclin B limitation and the DNA-replication checkpoint.
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Affiliation(s)
- Jun-Yuan Ji
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA
| | - Jayne M. Squirrell
- Laboratory of Molecular Biology, University of Wisconsin, Madison, WI 53706, USA
| | - Gerold Schubiger
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA
- Author for correspondence ()
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Ji JY, Haghnia M, Trusty C, Goldstein LSB, Schubiger G. A genetic screen for suppressors and enhancers of the Drosophila cdk1-cyclin B identifies maternal factors that regulate microtubule and microfilament stability. Genetics 2002; 162:1179-95. [PMID: 12454065 PMCID: PMC1462342 DOI: 10.1093/genetics/162.3.1179] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [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] [Indexed: 01/11/2023] Open
Abstract
Coordination between cell-cycle progression and cytoskeletal dynamics is important for faithful transmission of genetic information. In early Drosophila embryos, increasing maternal cyclin B leads to higher Cdk1-CycB activity, shorter microtubules, and slower nuclear movement during cycles 5-7 and delays in nuclear migration to the cortex at cycle 10. Later during cycle 14 interphase of six cycB embryos, we observed patches of mitotic nuclei, chromosome bridges, abnormal nuclear distribution, and small and large nuclei. These phenotypes indicate disrupted coordination between the cell-cycle machinery and cytoskeletal function. Using these sensitized phenotypes, we performed a dosage-sensitive genetic screen to identify maternal proteins involved in this process. We identified 10 suppressors classified into three groups: (1) gene products regulating Cdk1 activities, cdk1 and cyclin A; (2) gene products interacting with both microtubules and microfilaments, Actin-related protein 87C; and (3) gene products interacting with microfilaments, chickadee, diaphanous, Cdc42, quail, spaghetti-squash, zipper, and scrambled. Interestingly, most of the suppressors that rescue the astral microtubule phenotype also reduce Cdk1-CycB activities and are microfilament-related genes. This suggests that the major mechanism of suppression relies on the interactions among Cdk1-CycB, microtubule, and microfilament networks. Our results indicate that the balance among these different components is vital for normal early cell cycles and for embryonic development. Our observations also indicate that microtubules and cortical microfilaments antagonize each other during the preblastoderm stage.
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Affiliation(s)
- Jun-Yuan Ji
- Department of Zoology, University of Washington, Seattle 98195-1800, USA
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50
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Zhai YJ, Wang RX, Ji JY, Wang G. [Pharmacognostical identification of antelope horn(Cornu Saigae Tataricae) and its adulterants]. Zhongguo Zhong Yao Za Zhi 2000; 25:334-7. [PMID: 12512419] [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] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To provide appropriate information and scientific basis for identifying antelope horn (Saiga tatarica) contained in traditional Chinese patent medicines, and formulate relevant quality criteria through experiments. METHOD Conducting comparative identification of macroscopic and microscopic characteristics of antelope horn(Saige tatarica) and its adulterants (Procapra gutturosa, Pantholops hodgsoni, Ovis ammon and Capra hircus) and giving a comparative table and an indented key to the main characteristics. RESULT AND CONCLUSION There are remarkable differences between the authentic product and adulterants in both macroscopic and microscopic characteristics.
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Affiliation(s)
- Y J Zhai
- Department of Chinese Materia Medica, Liaoning College of TCM, Shenyang 110032, Liaoning, China
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