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Kong Y, Luo Y, Zheng S, Yang J, Zhang D, Zhao Y, Zheng H, An M, Lin Y, Ai L, Diao X, Lin Q, Chen C, Chen R. Mutant KRAS Mediates circARFGEF2 Biogenesis to Promote Lymphatic Metastasis of Pancreatic Ductal Adenocarcinoma. Cancer Res 2023; 83:3077-3094. [PMID: 37363990 PMCID: PMC10502454 DOI: 10.1158/0008-5472.can-22-3997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 04/05/2023] [Accepted: 06/21/2023] [Indexed: 06/28/2023]
Abstract
Circular RNAs (circRNA) contribute to cancer stemness, proliferation, and metastasis. The biogenesis of circRNAs can be impacted by the genetic landscape of tumors. Herein, we identified a novel circRNA, circARFGEF2 (hsa_circ_0060665), which was upregulated in KRASG12D pancreatic ductal adenocarcinoma (PDAC) and positively associated with KRASG12D PDAC lymph node (LN) metastasis. CircARFGEF2 overexpression significantly facilitated KRASG12D PDAC LN metastasis in vitro and in vivo. Mechanistically, circARFGEF2 biogenesis in KRASG12D PDAC was significantly activated by the alternative splicing factor QKI-5, which recruited U2AF35 to facilitate spliceosome assembly. QKI-5 bound the QKI binding motifs and neighboring reverse complement sequence in intron 3 and 6 of ARFGEF2 pre-mRNA to facilitate circARFGEF2 biogenesis. CircARFGEF2 sponged miR-1205 and promoted the activation of JAK2, which phosphorylated STAT3 to trigger KRASG12D PDAC lymphangiogenesis and LN metastasis. Importantly, circARFGEF2 silencing significantly inhibited LN metastasis in the KrasG12D/+Trp53R172H/+Pdx-1-Cre (KPC) mouse PDAC model. These findings provide insight into the mechanism and metastasis-promoting function of mutant KRAS-mediated circRNA biogenesis. SIGNIFICANCE Increased splicing-mediated biogenesis of circARFGEF2 in KRAS-mutant pancreatic ductal adenocarcinoma activates JAK2-STAT3 signaling and triggers lymph node metastasis, suggesting circARFGEF2 could be a therapeutic target to inhibit pancreatic cancer progression.
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Affiliation(s)
- Yao Kong
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, P.R. China
| | - Yuming Luo
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Shangyou Zheng
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Jiabin Yang
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
- School of Medicine, South China University of Technology, Guangzhou, Guangdong, P.R. China
| | - Dingwen Zhang
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
- School of Medicine, South China University of Technology, Guangzhou, Guangdong, P.R. China
| | - Yue Zhao
- Department of Tumor Intervention, Sun Yat-sen University First Affiliated Hospital, Guangzhou, Guangdong, P.R. China
| | - Hanhao Zheng
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, P.R. China
| | - Mingjie An
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, P.R. China
| | - Yan Lin
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, P.R. China
| | - Le Ai
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, P.R. China
- Department of Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
| | - Xiayao Diao
- Department of Thoracic Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Qing Lin
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
| | - Changhao Chen
- Department of Urology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P.R. China
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital, State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, P.R. China
| | - Rufu Chen
- Department of Pancreas Center, Department of General Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, Guangdong, P.R. China
- School of Medicine, South China University of Technology, Guangzhou, Guangdong, P.R. China
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, P.R. China
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Huang H, Lin D, Hu L, Wang J, Yu Y, Yu Y, Li K, Chen F. RNA Binding Protein Quaking Promotes Hypoxia-induced Smooth Muscle Reprogramming in Pulmonary Hypertension. Am J Respir Cell Mol Biol 2023; 69:159-171. [PMID: 37146099 DOI: 10.1165/rcmb.2022-0349oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 05/04/2023] [Indexed: 05/07/2023] Open
Abstract
Pulmonary hypertension (PH) is a devastating disease characterized by progressive increases in pulmonary vascular resistance and remodeling, which eventually leads to right ventricular failure and death. The aim of this study was to identify novel molecular mechanisms involved in the hyperproliferation of pulmonary artery smooth muscle cells (PASMCs) in PH. In this study, we first demonstrated that the mRNA and protein expression amounts of QKI (Quaking), an RNA-binding protein, were elevated in human and rodent PH lung and pulmonary artery tissues and hypoxic human PASMCs. QKI deficiency attenuated PASMC proliferation in vitro and vascular remodeling in vivo. Next, we elucidated that QKI increases STAT3 (signal transducer and activator of transcription 3) mRNA stability by binding to its 3' untranslated region. QKI inhibition reduced STAT3 expression and alleviated PASMC proliferation in vitro. Moreover, we also observed that the upregulated expression of STAT3 promoted PASMC proliferation in vitro and in vivo. In addition, as a transcription factor, STAT3 bound to microRNA (miR)-146b promoter to enhance its expression. We further showed that miR-146b promoted the proliferation of smooth muscle cells by inhibiting STAT1 and TET2 (Tet methylcytosine dioxygenase 2) during pulmonary vascular remodeling. This study has demonstrated new mechanistic insights into hypoxic reprogramming that arouses vascular remodeling, thus providing proof of concept for targeting vascular remodeling by directly modulating the QKI-STAT3-miR-146b pathway in PH.
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Affiliation(s)
| | | | - Li Hu
- Department of Forensic Medicine and
| | - Jie Wang
- Department of Forensic Medicine and
| | | | | | - Kai Li
- Department of Forensic Medicine and
| | - Feng Chen
- Department of Forensic Medicine and
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, China
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Regulation of the Proliferation of Diabetic Vascular Endothelial Cells by Degrading Endothelial Cell Functional Genes with QKI-7. CONTRAST MEDIA & MOLECULAR IMAGING 2022; 2022:6177809. [PMID: 35711530 PMCID: PMC9187461 DOI: 10.1155/2022/6177809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/01/2022] [Accepted: 04/22/2022] [Indexed: 12/02/2022]
Abstract
Background Diabetes has emerged as one of the most serious and common chronic diseases of our times, causing life-threatening, disabling and costly complications, and reducing life expectancy. Studies have shown that cardiovascular morbidity is 1–3 times higher in diabetic patients than in normal people. There are many clinical and experimental data that prove that most of the complications of diabetes are related to atherosclerosis, which suggests that chronic hyperglycemia may induce an imbalance in the proliferation of vascular endothelial cells. Purpose This study aims to explore the relationship between QKI-7 and vascular endothelial cell dysfunction and lay a foundation for further clarifying the molecular mechanism of endothelial cell damage in the process of diabetes with atherosclerosis. Methods We chose blood samples and pluripotent stem cells and vascular endothelial cells of hospitalized patients with diabetes and diabetes atherosclerosis as research subjects. The expression levels of endothelial cell proliferation and genes related to endothelial cell proliferation were analyzed by RT-qPCR and Western blot, to study the influence of QKi-7 on the physiological state of endothelial cells. Through gene knockdown experiment, the effects of QKi-7 knockdown on functional genes and physiological functions of endothelial cells were analyzed. Finally, RNA immunoprecipitation was used to test the mutual effect among QKI-7 and the transcription level of functional genes, and the mRNA attenuation experiment proved that QKI-7 participated in the degradation process of functional genes. Results The findings of the RT-qPCR and Western blot tests revealed that QKI-7 was highly expressed in blood samples of diabetic patients and atherosclerosis as well as in endothelial cells induced by human pluripotent stem cells and human vascular endothelial cells after high-glucose treatment. Overexpression and high glucose of QKI-7 resulted in inhibiting expressed function genes CD144, NLGN1, and TSG6 and upregulation of inflammatory factors TNF-α, IL-1β, and IFN-γ, leading to excessive proliferation of endothelial cells. After QKI-7 gene knockdown, the expression levels of CD144, NLGN1, and TSG6, inflammatory factors TNF-α, IL-1β, and IFN-γ, and the cell proliferation rate all returned to normal levels. RNA immunoprecipitation showed that QKi-7 interacted with CD144, NLGN1, and TSG6 mRNAs and was involved in the transcriptional degradation of functional genes through their interactions. Conclusion This research initially revealed the relevant molecular mechanism of QKI-7 leading to the excessive proliferation of endothelial cells in diabetic and atherosclerotic patients. In view of the role of QKI-7 in diabetic vascular complications, we provided a potential target for clinical diabetes treatment strategies in the future.
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Emerging Roles of RNA-Binding Proteins in Neurodevelopment. J Dev Biol 2022; 10:jdb10020023. [PMID: 35735914 PMCID: PMC9224834 DOI: 10.3390/jdb10020023] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/02/2022] [Accepted: 06/08/2022] [Indexed: 02/06/2023] Open
Abstract
Diverse cell types in the central nervous system (CNS) are generated by a relatively small pool of neural stem cells during early development. Spatial and temporal regulation of stem cell behavior relies on precise coordination of gene expression. Well-studied mechanisms include hormone signaling, transcription factor activity, and chromatin remodeling processes. Much less is known about downstream RNA-dependent mechanisms including posttranscriptional regulation, nuclear export, alternative splicing, and transcript stability. These important functions are carried out by RNA-binding proteins (RBPs). Recent work has begun to explore how RBPs contribute to stem cell function and homeostasis, including their role in metabolism, transport, epigenetic regulation, and turnover of target transcripts. Additional layers of complexity are provided by the different target recognition mechanisms of each RBP as well as the posttranslational modifications of the RBPs themselves that alter function. Altogether, these functions allow RBPs to influence various aspects of RNA metabolism to regulate numerous cellular processes. Here we compile advances in RNA biology that have added to our still limited understanding of the role of RBPs in neurodevelopment.
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Chen J, Gu J, Tang M, Liao Z, Tang R, Zhou L, Su M, Jiang J, Hu Y, Chen Y, Zhou Y, Liao Q, Xiong W, Zhou J, Tang Y, Nie S. Regulation of cancer progression by circRNA and functional proteins. J Cell Physiol 2021; 237:373-388. [PMID: 34676546 DOI: 10.1002/jcp.30608] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 12/13/2022]
Abstract
Circular RNAs (circRNAs) are closed back-splicing products of precursor mRNA in eukaryotes. Compared with linear mRNAs, circRNAs have a special structure and stable expression. A large number of studies have provided different regulatory mechanisms of circRNAs in tumors. Challenges exist in understanding the control of circRNAs because of their sequence overlap with linear mRNA. Here, we survey the most recent progress regarding the regulation of circRNA biogenesis by RNA-binding proteins, one of the vital functional proteins. Furthermore, substantial circRNAs exert compelling biological roles by acting as protein sponges, by being translated themselves or regulating posttranslational modifications of proteins. This review will help further explore more types of functional proteins that interact with circRNA in cancer and reveal other unknown mechanisms of circRNA regulation.
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Affiliation(s)
- Junhong Chen
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,The University of South China, Hengyang, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Jie Gu
- Department of Geriatric Urology, Xiangya International Medical Center, Xiangya Hospital, Central South University, Changsha, China.,Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Mengtian Tang
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,The University of South China, Hengyang, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Zhiqiang Liao
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,The University of South China, Hengyang, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Rui Tang
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,The University of South China, Hengyang, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Lianqing Zhou
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Min Su
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Central Laboratory, The Affiliated Cancer Hospital of Xiangya Medical School, Central South University, Changsha, China
| | - Jiarui Jiang
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Yingbin Hu
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Yongyi Chen
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Yujuan Zhou
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Qianjin Liao
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Central Laboratory, The Affiliated Cancer Hospital of Xiangya Medical School, Central South University, Changsha, China
| | - Wei Xiong
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Jumei Zhou
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of Radiotherapy, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Yanyan Tang
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Central Laboratory, The Affiliated Cancer Hospital of Xiangya Medical School, Central South University, Changsha, China
| | - Shaolin Nie
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Department of Colorectal Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
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Chen J, Li N, Wang X, Chen J, Zhang JZH, Zhu T. Molecular mechanism related to the binding of fluorophores to Mango-II revealed by multiple-replica molecular dynamics simulations. Phys Chem Chem Phys 2021; 23:10636-10649. [PMID: 33904542 DOI: 10.1039/d0cp06438f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recently, RNA aptamers activating small-molecule fluorophores have been successfully applied to tag and track RNAs in vivo. It is of significance to investigate the molecular mechanism of the fluorophore-RNA aptamer bindings at the atomic level to seek a possible pathway to enhance the fluorescence efficiency of fluorophores. In this work, multiple replica molecular dynamics (MRMD) simulations, essential dynamics (ED) analysis, and hierarchical clustering analysis were coupled to probe the effect of A22U mutation on the binding of two fluorophores, TO1-Biotin (TO1) and TO3-Biotin (TO3), to the Mango-II RNA aptamer (Mango-II). ED analysis reveals that A22U induces alterations in the binding pocket and sites of TO1 and TO3 to the Mango-II, which in turn tunes the fluorophore-RNA interface and changes the interactions of TO1 and TO3 with separate nucleotides of Mango-II. Dynamics analyses also uncover that A22U exerts the opposite impact on the molecular surface areas of the Mango-II and sugar puckers of nucleotides 22 and 23 in Mango-II complexed with TO1 and TO3. Moreover, the calculations of binding free energies suggest that A22U strengthens the binding ability of TO1 to the mutated Mango-II but weakens TO3 to the mutated Mango-II when compared with WT. These findings imply that point mutation in nucleotides possibly tune the fluorescence of fluorophores binding to RNA aptamers, providing a possible scheme to enhance the fluorescence of fluorophores.
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Affiliation(s)
- Junxiao Chen
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, People's Republic of China. and School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology, Jinan, 250353, People's Republic of China
| | - Na Li
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, People's Republic of China.
| | - Xingyu Wang
- NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, People's Republic of China
| | - Jianzhong Chen
- School of Science, Shandong Jiaotong University, Jinan 250357, People's Republic of China.
| | - John Z H Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, People's Republic of China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, People's Republic of China
| | - Tong Zhu
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, People's Republic of China. and NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai, People's Republic of China and Shandong Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou 253023, China
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7
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Shin S, Zhou H, He C, Wei Y, Wang Y, Shingu T, Zeng A, Wang S, Zhou X, Li H, Zhang Q, Mo Q, Long J, Lan F, Chen Y, Hu J. Qki activates Srebp2-mediated cholesterol biosynthesis for maintenance of eye lens transparency. Nat Commun 2021; 12:3005. [PMID: 34021134 PMCID: PMC8139980 DOI: 10.1038/s41467-021-22782-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 03/23/2021] [Indexed: 02/04/2023] Open
Abstract
Defective cholesterol biosynthesis in eye lens cells is often associated with cataracts; however, how genes involved in cholesterol biosynthesis are regulated in lens cells remains unclear. Here, we show that Quaking (Qki) is required for the transcriptional activation of genes involved in cholesterol biosynthesis in the eye lens. At the transcriptome level, lens-specific Qki-deficient mice present downregulation of genes associated with the cholesterol biosynthesis pathway, resulting in a significant reduction of total cholesterol level in the eye lens. Mice with Qki depletion in lens epithelium display progressive accumulation of protein aggregates, eventually leading to cataracts. Notably, these defects are attenuated by topical sterol administration. Mechanistically, we demonstrate that Qki enhances cholesterol biosynthesis by recruiting Srebp2 and Pol II in the promoter regions of cholesterol biosynthesis genes. Supporting its function as a transcription co-activator, we show that Qki directly interacts with single-stranded DNA. In conclusion, we propose that Qki-Srebp2-mediated cholesterol biosynthesis is essential for maintaining the cholesterol level that protects lens from cataract development.
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Affiliation(s)
- Seula Shin
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Cancer Biology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Hao Zhou
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Chenxi He
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, and Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yanjun Wei
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yunfei Wang
- Clinical Science Division, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA
| | - Takashi Shingu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ailiang Zeng
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Shaobo Wang
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Xin Zhou
- Cancer Research Institute of Jilin University, The First Hospital of Jilin University, Jilin, China
| | - Hongtao Li
- Department of Oncology, Affiliated Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Qiang Zhang
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Qinling Mo
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Jiafu Long
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Fei Lan
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, and Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yiwen Chen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jian Hu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
- Cancer Biology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.
- Neuroscience Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.
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Krepl M, Dendooven T, Luisi BF, Sponer J. MD simulations reveal the basis for dynamic assembly of Hfq-RNA complexes. J Biol Chem 2021; 296:100656. [PMID: 33857481 PMCID: PMC8121710 DOI: 10.1016/j.jbc.2021.100656] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 01/05/2023] Open
Abstract
The conserved protein Hfq is a key factor in the RNA-mediated control of gene expression in most known bacteria. The transient intermediates Hfq forms with RNA support intricate and robust regulatory networks. In Pseudomonas, Hfq recognizes repeats of adenine–purine–any nucleotide (ARN) in target mRNAs via its distal binding side, and together with the catabolite repression control (Crc) protein, assembles into a translation–repression complex. Earlier experiments yielded static, ensemble-averaged structures of the complex, but details of its interface dynamics and assembly pathway remained elusive. Using explicit solvent atomistic molecular dynamics simulations, we modeled the extensive dynamics of the Hfq–RNA interface and found implications for the assembly of the complex. We predict that syn/anti flips of the adenine nucleotides in each ARN repeat contribute to a dynamic recognition mechanism between the Hfq distal side and mRNA targets. We identify a previously unknown binding pocket that can accept any nucleotide and propose that it may serve as a ‘status quo’ staging point, providing nonspecific binding affinity, until Crc engages the Hfq–RNA binary complex. The dynamical components of the Hfq–RNA recognition can speed up screening of the pool of the surrounding RNAs, participate in rapid accommodation of the RNA on the protein surface, and facilitate competition among different RNAs. The register of Crc in the ternary assembly could be defined by the recognition of a guanine-specific base–phosphate interaction between the first and last ARN repeats of the bound RNA. This dynamic substrate recognition provides structural rationale for the stepwise assembly of multicomponent ribonucleoprotein complexes nucleated by Hfq–RNA binding.
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Affiliation(s)
- Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic.
| | - Tom Dendooven
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom; MRC-LMB, Cambridge, United Kingdom
| | - Ben F Luisi
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Jiri Sponer
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
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