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Zhang Q, Li Q, Wang Y, Zhang Y, Peng R, Wang Z, Zhu B, Xu L, Gao X, Chen Y, Gao H, Hu J, Qian C, Ma M, Duan R, Li J, Zhang L. Characterization of Chromatin Accessibility in Fetal Bovine Chondrocytes. Animals (Basel) 2023; 13:1875. [PMID: 37889831 PMCID: PMC10251841 DOI: 10.3390/ani13111875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/28/2023] [Accepted: 05/29/2023] [Indexed: 10/29/2023] Open
Abstract
Despite significant advances of the bovine epigenome investigation, new evidence for the epigenetic basis of fetal cartilage development remains lacking. In this study, the chondrocytes were isolated from long bone tissues of bovine fetuses at 90 days. The Assay for Transposase-Accessible Chromatin with high throughput sequencing (ATAC-seq) and transcriptome sequencing (RNA-seq) were used to characterize gene expression and chromatin accessibility profile in bovine chondrocytes. A total of 9686 open chromatin regions in bovine fetal chondrocytes were identified and 45% of the peaks were enriched in the promoter regions. Then, all peaks were annotated to the nearest gene for Gene Ontology (GO) and Kyoto Encylopaedia of Genes and Genomes (KEGG) analysis. Growth and development-related processes such as amide biosynthesis process (GO: 0043604) and translation regulation (GO: 006417) were enriched in the GO analysis. The KEGG analysis enriched endoplasmic reticulum protein processing signal pathway, TGF-β signaling pathway and cell cycle pathway, which are closely related to protein synthesis and processing during cell proliferation. Active transcription factors (TFs) were enriched by ATAC-seq, and were fully verified with gene expression levels obtained by RNA-seq. Among the top50 TFs from footprint analysis, known or potential cartilage development-related transcription factors FOS, FOSL2 and NFY were found. Overall, our data provide a theoretical basis for further determining the regulatory mechanism of cartilage development in bovine.
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Affiliation(s)
- Qi Zhang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Qian Li
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Yahui Wang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Yapeng Zhang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Ruiqi Peng
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Zezhao Wang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Bo Zhu
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Lingyang Xu
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Xue Gao
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Yan Chen
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Huijiang Gao
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Junwei Hu
- Academy of Pingliang Red Cattle, 492 South Ring Road, Kongtong District, Pingliang 744000, China; (J.H.); (C.Q.); (M.M.); (R.D.)
| | - Cong Qian
- Academy of Pingliang Red Cattle, 492 South Ring Road, Kongtong District, Pingliang 744000, China; (J.H.); (C.Q.); (M.M.); (R.D.)
| | - Minghao Ma
- Academy of Pingliang Red Cattle, 492 South Ring Road, Kongtong District, Pingliang 744000, China; (J.H.); (C.Q.); (M.M.); (R.D.)
| | - Rui Duan
- Academy of Pingliang Red Cattle, 492 South Ring Road, Kongtong District, Pingliang 744000, China; (J.H.); (C.Q.); (M.M.); (R.D.)
| | - Junya Li
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
| | - Lupei Zhang
- Key Laboratory of Animal (Poultry) Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (Q.Z.); (Q.L.); (Y.W.); (Y.Z.); (R.P.); (Z.W.); (B.Z.); (L.X.); (X.G.); (Y.C.); (H.G.)
- Academy of Pingliang Red Cattle, 492 South Ring Road, Kongtong District, Pingliang 744000, China; (J.H.); (C.Q.); (M.M.); (R.D.)
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Nakamichi R, Kurimoto R, Tabata Y, Asahara H. Transcriptional, epigenetic and microRNA regulation of growth plate. Bone 2020; 137:115434. [PMID: 32422296 PMCID: PMC7387102 DOI: 10.1016/j.bone.2020.115434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/13/2020] [Accepted: 05/13/2020] [Indexed: 11/22/2022]
Abstract
Endochondral ossification is a critical event in bone formation, particularly in long shaft bones. Many cellular differentiation processes work in concert to facilitate the generation of cartilage primordium to formation of trabecular structures, all of which occur within the growth plate. Previous studies have revealed that the growth plate is tightly regulated by various transcription factors, epigenetic systems, and microRNAs. Hence, understanding these mechanisms that regulate the growth plate is crucial to furthering the current understanding on skeletal diseases, and in formulating effective treatment strategies. In this review, we focus on describing the function and mechanisms of the transcription factors, epigenetic systems, and microRNAs known to regulate the growth plate.
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Affiliation(s)
- Ryo Nakamichi
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, MBB-102, La Jolla, CA 92037, USA; Department of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Ryota Kurimoto
- Department of Systems Biomedicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Yusuke Tabata
- Department of Orthopaedic Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
| | - Hirosi Asahara
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, MBB-102, La Jolla, CA 92037, USA; Department of Systems Biomedicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
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Tang J, Liao Y, He S, Shi J, Peng L, Xu X, Xie F, Diao N, Huang J, Xie Q, Lin C, Luo X, Liao K, Ma J, Li J, Zhou D, Li Z, Xu J, Zhong C, Wang G, Bai L. Autocrine parathyroid hormone-like hormone promotes intrahepatic cholangiocarcinoma cell proliferation via increased ERK/JNK-ATF2-cyclinD1 signaling. J Transl Med 2017; 15:238. [PMID: 29178939 PMCID: PMC5702246 DOI: 10.1186/s12967-017-1342-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 11/04/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND AIMS Intrahepatic cholangiocarcinoma (ICC) is an aggressive tumor with a high fatality rate. It was recently found that parathyroid hormone-like hormone (PTHLH) was frequently overexpressed in ICC compared with non-tumor tissue. This study aimed to elucidate the underlying mechanisms of PTHLH in ICC development. METHODS The CCK-8 assay, colony formation assays, flow cytometry and a xenograft model were used to examine the role of PTHLH in ICC cells proliferation. Immunohistochemistry (IHC) and western blot assays were used to detect target proteins. Luciferase reporter, chromatin immunoprecipitation (ChIP) and DNA pull-down assays were used to verify the transcription regulation of activating transcription factor-2 (ATF2). RESULTS PTHLH was significantly upregulated in ICC compared with adjacent and normal tissues. Upregulation of PTHLH indicated a poor pathological differentiation and intrahepatic metastasis. Functional study demonstrated that PTHLH silencing markedly suppressed ICC cells growth, while specific overexpression of PTHLH has the opposite effect. Mechanistically, secreted PTHLH could promote ICC cell growth by activating extracellular signal-related kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways, and subsequently upregulated ATF2 and cyclinD1 expression. Further study found that the promoter activity of PTHLH were negatively regulated by ATF2, indicating that a negative feedback loop exists. CONCLUSIONS Our findings demonstrated that the ICC-secreted PTHLH plays a characteristic growth-promoting role through activating the canonical ERK/JNK-ATF2-cyclinD1 signaling pathways in ICC development. We identified a negative feedback loop formed by ATF2 and PTHLH. In this study, we explored the therapeutic implication for ICC patients.
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Affiliation(s)
- Jing Tang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Yan Liao
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Shuying He
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Jie Shi
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Liang Peng
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Xiaoping Xu
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Fang Xie
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Na Diao
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Jinlan Huang
- Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Qian Xie
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Chuang Lin
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiaoying Luo
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Kaili Liao
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Juanjuan Ma
- Department of Gastroenterology, Dali Bai Autonomous Prefecture People's Hospital, Dali, Yunnan, China
| | - Jingyi Li
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Daichao Zhou
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Zhijun Li
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Jun Xu
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Chao Zhong
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Guozhen Wang
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China
| | - Lan Bai
- Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Nanfang Hospital, Southern Medical University, No. 1838, Guangzhou Avenue North, Baiyun District, Guangzhou, Guangdong, China.
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Li M, Wu X, Liu N, Li X, Meng F, Song S. Silencing of ATF2 inhibits growth of pancreatic cancer cells and enhances sensitivity to chemotherapy. Cell Biol Int 2017; 41:599-610. [PMID: 28318081 DOI: 10.1002/cbin.10760] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/04/2017] [Indexed: 01/03/2023]
Affiliation(s)
- Mu Li
- Department of General Surgery; Pancreatic Surgery; The First Affiliated Hospital of China Medical University; Shenyang 110001 People's Republic of China
| | - Xingda Wu
- Department of General Surgery; Pancreatic Surgery; The First Affiliated Hospital of China Medical University; Shenyang 110001 People's Republic of China
| | - Ning Liu
- Department of General Surgery; Pancreatic Surgery; The First Affiliated Hospital of China Medical University; Shenyang 110001 People's Republic of China
| | - Xiaoying Li
- Department of General Surgery; Pancreatic Surgery; The First Affiliated Hospital of China Medical University; Shenyang 110001 People's Republic of China
| | - Fanbin Meng
- Department of General Surgery; Pancreatic Surgery; The First Affiliated Hospital of China Medical University; Shenyang 110001 People's Republic of China
| | - Shaowei Song
- Department of General Surgery; Pancreatic Surgery; The First Affiliated Hospital of China Medical University; Shenyang 110001 People's Republic of China
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Notch signaling indirectly promotes chondrocyte hypertrophy via regulation of BMP signaling and cell cycle arrest. Sci Rep 2016; 6:25594. [PMID: 27146698 PMCID: PMC4857138 DOI: 10.1038/srep25594] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/20/2016] [Indexed: 01/06/2023] Open
Abstract
Cell cycle regulation is critical for chondrocyte differentiation and hypertrophy. Recently we identified the Notch signaling pathway as an important regulator of chondrocyte proliferation and differentiation during mouse cartilage development. To investigate the underlying mechanisms, we assessed the role for Notch signaling regulation of the cell cycle during chondrocyte differentiation. Real-time RT-PCR data showed that over-expression of the Notch Intracellular Domain (NICD) significantly induced the expression of p57, a cell cycle inhibitor, in chondrocytes. Flow cytometric analyses further confirmed that over-expression of NICD in chondrocytes enhances the G0/G1 cell cycle transition and cell cycle arrest. In contrast, treatment of chondrocytes with the Notch inhibitor, DAPT, decreased both endogenous and BMP2-induced SMAD 1/5/8 phosphorylation and knockdown of SMAD 1/5/8 impaired NICD-induced chondrocyte differentiation and p57 expression. Co-immunoprecipitation using p-SMAD 1/5/8 and NICD antibodies further showed a strong interaction of these proteins during chondrocyte maturation. Finally, RT-PCR and Western blot results revealed a significant reduction in the expression of the SMAD-related phosphatase, PPM1A, following NICD over-expression. Taken together, our results demonstrate that Notch signaling induces cell cycle arrest and thereby initiates chondrocyte hypertrophy via BMP/SMAD-mediated up-regulation of p57.
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Broekgaarden M, Weijer R, van Gulik TM, Hamblin MR, Heger M. Tumor cell survival pathways activated by photodynamic therapy: a molecular basis for pharmacological inhibition strategies. Cancer Metastasis Rev 2015; 34:643-90. [PMID: 26516076 PMCID: PMC4661210 DOI: 10.1007/s10555-015-9588-7] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Photodynamic therapy (PDT) has emerged as a promising alternative to conventional cancer therapies such as surgery, chemotherapy, and radiotherapy. PDT comprises the administration of a photosensitizer, its accumulation in tumor tissue, and subsequent irradiation of the photosensitizer-loaded tumor, leading to the localized photoproduction of reactive oxygen species (ROS). The resulting oxidative damage ultimately culminates in tumor cell death, vascular shutdown, induction of an antitumor immune response, and the consequent destruction of the tumor. However, the ROS produced by PDT also triggers a stress response that, as part of a cell survival mechanism, helps cancer cells to cope with the PDT-induced oxidative stress and cell damage. These survival pathways are mediated by the transcription factors activator protein 1 (AP-1), nuclear factor E2-related factor 2 (NRF2), hypoxia-inducible factor 1 (HIF-1), nuclear factor κB (NF-κB), and those that mediate the proteotoxic stress response. The survival pathways are believed to render some types of cancer recalcitrant to PDT and alter the tumor microenvironment in favor of tumor survival. In this review, the molecular mechanisms are elucidated that occur post-PDT to mediate cancer cell survival, on the basis of which pharmacological interventions are proposed. Specifically, pharmaceutical inhibitors of the molecular regulators of each survival pathway are addressed. The ultimate aim is to facilitate the development of adjuvant intervention strategies to improve PDT efficacy in recalcitrant solid tumors.
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Affiliation(s)
- Mans Broekgaarden
- Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Ruud Weijer
- Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Thomas M van Gulik
- Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Dermatology, Harvard Medical School, Boston, MA, USA
- Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA, USA
| | - Michal Heger
- Department of Experimental Surgery, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
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Zhang J, Pan C, Xu T, Niu Z, Ma C, Xu C. Interleukin 18 augments growth ability via NF-κB and p38/ATF2 pathways by targeting cyclin B1, cyclin B2, cyclin A2, and Bcl-2 in BRL-3A rat liver cells. Gene 2015; 563:45-51. [DOI: 10.1016/j.gene.2015.03.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/04/2015] [Indexed: 12/13/2022]
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8
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Cameron TL, Gresshoff IL, Bell KM, Piróg KA, Sampurno L, Hartley CL, Sanford EM, Wilson R, Ermann J, Boot-Handford RP, Glimcher LH, Briggs MD, Bateman JF. Cartilage-specific ablation of XBP1 signaling in mouse results in a chondrodysplasia characterized by reduced chondrocyte proliferation and delayed cartilage maturation and mineralization. Osteoarthritis Cartilage 2015; 23:661-70. [PMID: 25600960 DOI: 10.1016/j.joca.2015.01.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/07/2014] [Accepted: 01/04/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the in vivo role of the IRE1/XBP1 unfolded protein response (UPR) signaling pathway in cartilage. DESIGN Xbp1(flox/flox).Col2a1-Cre mice (Xbp1(CartΔEx2)), in which XBP1 activity is ablated specifically from cartilage, were analyzed histomorphometrically by Alizarin red/Alcian blue skeletal preparations and X-rays to examine overall bone growth, histological stains to measure growth plate zone length, chondrocyte organization, and mineralization, and immunofluorescence for collagen II, collagen X, and IHH. Bromodeoxyuridine (BrdU) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analyses were used to measure chondrocyte proliferation and cell death, respectively. Chondrocyte cultures and microdissected growth plate zones were analyzed for expression profiling of chondrocyte proliferation or endoplasmic reticulum (ER) stress markers by Quantitative PCR (qPCR), and of Xbp1 mRNA splicing by RT-PCR to monitor IRE1 activation. RESULTS Xbp1(CartΔEx2) displayed a chondrodysplasia involving dysregulated chondrocyte proliferation, growth plate hypertrophic zone shortening, and IRE1 hyperactivation in chondrocytes. Deposition of collagens II and X in the Xbp1(CartΔEx2) growth plate cartilage indicated that XBP1 is not required for matrix protein deposition or chondrocyte hypertrophy. Analyses of mid-gestation long bones revealed delayed ossification in Xbp1(CartΔEx2) embryos. The rate of chondrocyte cell death was not significantly altered, and only minimal alterations in the expression of key markers of chondrocyte proliferation were observed in the Xbp1(CartΔEx2) growth plate. IRE1 hyperactivation occurred in Xbp1(CartΔEx2) chondrocytes but was not sufficient to induce regulated IRE1-dependent decay (RIDD) or a classical UPR. CONCLUSION Our work suggests roles for XBP1 in regulating chondrocyte proliferation and the timing of mineralization during endochondral ossification, findings which have implications for both skeletal development and disease.
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Affiliation(s)
- T L Cameron
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - I L Gresshoff
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - K M Bell
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - K A Piróg
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK.
| | - L Sampurno
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - C L Hartley
- Central Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK.
| | - E M Sanford
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - R Wilson
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - J Ermann
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - R P Boot-Handford
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK.
| | - L H Glimcher
- Weill Cornell Medical College, Cornell University, New York, NY, USA.
| | - M D Briggs
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK.
| | - J F Bateman
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.
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9
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The regulatory role of activating transcription factor 2 in inflammation. Mediators Inflamm 2014; 2014:950472. [PMID: 25049453 PMCID: PMC4090481 DOI: 10.1155/2014/950472] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 05/30/2014] [Indexed: 01/06/2023] Open
Abstract
Activating transcription factor 2 (ATF2) is a member of the leucine zipper family of DNA-binding proteins and is widely distributed in tissues including the liver, lung, spleen, and kidney. Like c-Jun and c-Fos, ATF2 responds to stress-related stimuli and may thereby influence cell proliferation, inflammation, apoptosis, oncogenesis, neurological development and function, and skeletal remodeling. Recent studies clarify the regulatory role of ATF2 in inflammation and describe potential inhibitors of this protein. In this paper, we summarize the properties and functions of ATF2 and explore potential applications of ATF2 inhibitors as tools for research and for the development of immunosuppressive and anti-inflammatory drugs.
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10
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Canova MJ, Molle V. Bacterial serine/threonine protein kinases in host-pathogen interactions. J Biol Chem 2014; 289:9473-9. [PMID: 24554701 DOI: 10.1074/jbc.r113.529917] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In bacterial pathogenesis, monitoring and adapting to the dynamically changing environment in the host and an ability to disrupt host immune responses are critical. The virulence determinants of pathogenic bacteria include the sensor/signaling proteins of the serine/threonine protein kinase (STPK) family that have a dual role of sensing the environment and subverting specific host defense processes. STPKs can sense a wide range of signals and coordinate multiple cellular processes to mount an appropriate response. Here, we review some of the well studied bacterial STPKs that are essential virulence factors and that modify global host responses during infection.
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Affiliation(s)
- Marc J Canova
- From the Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS, UMR 5235, 34095 Montpellier Cedex 05, France
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11
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Desai S, Laskar S, Pandey B. Autocrine IL-8 and VEGF mediate epithelial–mesenchymal transition and invasiveness via p38/JNK-ATF-2 signalling in A549 lung cancer cells. Cell Signal 2013; 25:1780-91. [DOI: 10.1016/j.cellsig.2013.05.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/17/2013] [Indexed: 10/26/2022]
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12
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Kolupaeva V, Basilico C. Overexpression of cyclin E/CDK2 complexes overcomes FGF-induced cell cycle arrest in the presence of hypophosphorylated Rb proteins. Cell Cycle 2012; 11:2557-66. [PMID: 22713240 DOI: 10.4161/cc.20944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
FGF signaling inhibits chondrocyte proliferation and requires the function of the p107 and p130 members of the Rb protein family to execute growth arrest. p107 dephosphorylation plays a critical role in the chondrocyte response to FGF, as overexpression of cyclin D1/CDK4 complexes (the major p107 kinase) in rat chondrosarcoma (RCS) cells overcomes FGF-induced p107 dephosphorylation and growth arrest. In cells overexpressing cyclin D1/CDK4, FGF-induced downregulation of cyclin E/CDK2 activity was absent. To examine the role of cyclin E/CDK2 complexes in mediating FGF-induced growth arrest, this kinase was overexpressed in RCS cells. FGF-induced dephosphorylation of either p107 or p130 was not prevented by overexpressing cyclin E/CDK2 complexes. Unexpectedly, however, FGF-treated cells exhibited sustained proliferation even in the presence of hypophosphorylated p107 and p130. Both pocket proteins were able to form repressive complexes with E2F4 and E2F5 but these repressors were not translocated into the nucleus and therefore were unable to occupy their respective target DNA sites. Overexpressed cyclin E/CDK2 molecules were stably associated with p107 and p130 in FGF-treated cells in the context of E2F repressive complexes. Taken together, our data suggest a novel mechanism by which cyclin E/CDK2 complexes can promote cell cycle progression in the presence of dephosphorylated Rb proteins and provide a novel insight into the key Retinoblastoma/E2F/cyclin E pathway. Our data also highlight the importance of E2F4/p130 complexes for FGF-mediated growth arrest in chondrocytes.
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Affiliation(s)
- Victoria Kolupaeva
- Department of Microbiology, New York University School of Medicine, NY, USA.
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Li X, LuValle P. Activating transcription factor 2 targets c-Fos, but not c-Jun, in growth plate chondrocytes. J Cell Biochem 2011; 112:211-6. [PMID: 21069729 DOI: 10.1002/jcb.22925] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Activating transcription factor 2 (ATF-2), c-Fos, and c-Jun belong to the bZIP family of transcription factors. Promoters of c-Fos, c-Jun, cyclin D1, and cyclin A are targets of ATF-2 in primary mouse chondrocytes. An ATF-2 expression vector was co-transfected with either c-Fos or c-Jun promoters in mutant ATF-2 chondrocytes in order to show by luciferase assay that ATF-2 increased promoter activity of c-Fos, but not c-Jun. Chromatin immunoprecipitation (ChIP) assays revealed that ATF-2 bound with the c-Fos promoter at the -294 cyclic AMP response element (CRE) site, but did not bind to the TPA responsive element (TRE) or activating protein-1 (AP1) sites of the c-Jun promoter. Dominant-negative (dn) c-Fos inhibited cyclin D1 promoter activity. However, dn c-Jun had minimal effect on this same promoter activity. c-Fos was capable of interactions with both the cyclin D1 CRE and AP1 sites, while c-Jun co-operated specifically with the cyclin D1 CRE site. Neither c-Fos nor c-Jun had any effect on cyclin A promoter activity. c-Fos was unable to bind to the cyclin A AP1 or CRE sites. In contrast c-Jun was competent in interactions with cyclin A AP1-2 as well as the CRE.
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Affiliation(s)
- Xinying Li
- Department of Anatomy & Cell Biology, University of Florida, Gainesville, FL 32606-0235, USA
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Petit A, Demers CN, Girard-Lauriault PL, Stachura D, Wertheimer MR, Antoniou J, Mwale F. Effect of nitrogen-rich cell culture surfaces on type X collagen expression by bovine growth plate chondrocytes. Biomed Eng Online 2011; 10:4. [PMID: 21244651 PMCID: PMC3031272 DOI: 10.1186/1475-925x-10-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 01/18/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent evidence indicates that osteoarthritis (OA) may be a systemic disease since mesenchymal stem cells (MSCs) from OA patients express type X collagen, a marker of late stage chondrocyte hypertrophy (associated with endochondral ossification). We recently showed that the expression of type X collagen was suppressed when MSCs from OA patients were cultured on nitrogen (N)-rich plasma polymer layers, which we call "PPE:N" (N-doped plasma-polymerized ethylene, containing up to 36 atomic percentage (at.% ) of N. METHODS In the present study, we examined the expression of type X collagen in fetal bovine growth plate chondrocytes (containing hypertrophic chondrocytes) cultured on PPE:N. We also studied the effect of PPE:N on the expression of matrix molecules such as type II collagen and aggrecan, as well as on proteases (matrix metalloproteinase-13 (MMP-13) and molecules implicated in cell division (cyclin B2). Two other culture surfaces, "hydrophilic" polystyrene (PS, regular culture dishes) and nitrogen-containing cation polystyrene (Primaria®), were also investigated for comparison. RESULTS Results showed that type X collagen mRNA levels were suppressed when cultured for 4 days on PPE:N, suggesting that type X collagen is regulated similarly in hypertrophic chondrocytes and in human MSCs from OA patients. However, the levels of type X collagen mRNA almost returned to control value after 20 days in culture on these surfaces. Culture on the various surfaces had no significant effects on type II collagen, aggrecan, MMP-13, and cyclin B2 mRNA levels. CONCLUSION Hypertrophy is diminished by culturing growth plate chondrocytes on nitrogen-rich surfaces, a mechanism that is beneficial for MSC chondrogenesis. Furthermore, one major advantage of such "intelligent surfaces" over recombinant growth factors for tissue engineering and cartilage repair is potentially large cost-saving.
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Affiliation(s)
- Alain Petit
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, Montreal, QC, Canada
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Petit A, Wang HT, Girard-Lauriault PL, Wertheimer MR, Antoniou J, Mwale F. Novel insights into the mechanism of decreased expression of type X collagen in human mesenchymal stem cells from patients with osteoarthritis cultured on nitrogen-rich plasma polymers: implication of cyclooxygenase-1. J Biomed Mater Res A 2010; 94:744-50. [PMID: 20225218 DOI: 10.1002/jbm.a.32739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recent evidence indicates that a major drawback of current cartilage- and intervertebral disc (IVD) tissue engineering is that human mesenchymal stem cells (MSCs) from patients with osteoarthritis rapidly express type X collagen (COL10A1), a marker of late stage chondrocyte hypertrophy associated with endochondral ossification. We recently demonstrated that COL10A1 expression was inhibited in MSCs from patients with osteoarthritis cultured on nitrogen-rich plasma polymerized (PPE:N) coatings. Here, we sought to understand the mechanisms of action of this effect by culturing MSCs on PPE:N surfaces in the presence of different inhibitors of kinases and cyclooxygenases. The effect of PPE:N surfaces on COL10A1 expression was found to be mimicked by the cyclooxygenase inhibitor NPPB, but not by daphnetin (an inhibitor of protein kinases) nor by genistein (an inhibitor of tyrosine kinases). COL10A1 expression was also suppressed by the specific cyclooxygenase-1 (COX-1: SC-560) and 5-lipoxygenase (5-LOX: MK-866) inhibitors, but not by COX-2 (COX-2 inhibitor 2) and 12-LOX (baicalein) inhibitors. Finally, the incubation of MSCs on PPE:N surfaces inhibited the expression of COX-1 while 5-LOX was not expressed in these cells. Taken together, these results indicate that PPE:N surfaces inhibit COL10A1 expression via the suppression of COX-1.
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Affiliation(s)
- Alain Petit
- Lady Davis Institute for Medical Research, SMBD-Jewish General Hospital, Montreal, Quebec, Canada
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Li TF, Gao L, Sheu TJ, Sampson ER, Flick LM, Konttinen YT, Chen D, Schwarz EM, Zuscik MJ, Jonason JH, O'Keefe RJ. Aberrant hypertrophy in Smad3-deficient murine chondrocytes is rescued by restoring transforming growth factor beta-activated kinase 1/activating transcription factor 2 signaling: a potential clinical implication for osteoarthritis. ACTA ACUST UNITED AC 2010; 62:2359-69. [PMID: 20506210 DOI: 10.1002/art.27537] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE To investigate the biologic significance of Smad3 in the progression of osteoarthritis (OA), the crosstalk between Smad3 and activating transcription factor 2 (ATF-2) in the transforming growth factor beta (TGFbeta) signaling pathway, and the effects of ATF-2 overexpression and p38 activation in chondrocyte differentiation. METHODS Joint disease in Smad3-knockout (Smad3(-/-)) mice was examined by microfocal computed tomography and histologic analysis. Numerous in vitro methods including immunostaining, real-time polymerase chain reaction, Western blotting, an ATF-2 DNA-binding assay, and a p38 kinase activity assay were used to study the various signaling responses and protein interactions underlying the altered chondrocyte phenotype in Smad3(-/-) mice. RESULTS In Smad3(-/-) mice, an end-stage OA phenotype gradually developed. TGFbeta-activated kinase 1 (TAK1)/ATF-2 signaling was disrupted in Smad3(-/-) mouse chondrocytes at the level of p38 MAP kinase (MAPK) activation, resulting in reduced ATF-2 phosphorylation and transcriptional activity. Reintroduction of Smad3 into Smad3(-/-) cells restored the normal p38 response to TGFbeta. Phosphorylated p38 formed a complex with Smad3 by binding to a portion of Smad3 containing both the MAD homology 1 and linker domains. Additionally, Smad3 inhibited the dephosphorylation of p38 by MAPK phosphatase 1 (MKP-1). Both ATF-2 overexpression and p38 activation repressed type X collagen expression in wild-type and Smad3(-/-) chondrocytes. P38 was detected in articular cartilage and perichondrium; articular and sternal chondrocytes expressed p38 isoforms alpha, beta, and gamma, but not delta. CONCLUSION Smad3 is involved in both the onset and progression of OA. Loss of Smad3 abrogates TAK1/ATF-2 signaling, most likely by disrupting the Smad3-phosphorylated p38 complex, thereby promoting p38 dephosphorylation and inactivation by MKP-1. ATF-2 and p38 activation inhibit chondrocyte hypertrophy. Modulation of p38 isoform activity may provide a new therapeutic approach for OA.
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Affiliation(s)
- Tian-Fang Li
- University of Rochester, Rochester, New York 14642, USA
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Xiao L, Rao JN, Zou T, Liu L, Yu TX, Zhu XY, Donahue JM, Wang JY. Induced ATF-2 represses CDK4 transcription through dimerization with JunD inhibiting intestinal epithelial cell growth after polyamine depletion. Am J Physiol Cell Physiol 2010; 298:C1226-34. [PMID: 20181929 DOI: 10.1152/ajpcell.00021.2010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intestinal epithelium is a rapidly self-renewing tissue in the body, and its homeostasis is tightly regulated by numerous factors including polyamines. Decreased levels of cellular polyamines increase activating transcription factor (ATF)-2, but the exact role and mechanism of induced ATF-2 in the regulation of intestinal epithelial cell (IEC) growth remain elusive. Cyclin-dependent kinase (CDK) 4 is necessary for the G1-to-S phase transition during the cell cycle, and its expression is predominantly controlled at the transcription level. Here, we reported that induced ATF-2 following polyamine depletion repressed CDK4 gene transcription in IECs by increasing formation of the ATF-2/JunD heterodimers. ATF-2 formed complexes with JunD as measured by immunoprecipitation using the ATF-2 and JunD antibodies and by glutathione S-transferase (GST) pull-down assays using GST-ATF-2 fusion proteins. Studies using various mutants of GST-ATF-2 revealed that formation of the ATF-2/JunD dimers depended on the COOH-terminal basic region-leucine zipper domain of ATF-2. Polyamine depletion increased ATF-2/JunD complex and inhibited CDK4 transcription as indicated by a decrease in the levels of CDK4-promoter activity and its mRNA. ATF-2 silencing not only prevented inhibition of CDK4 transcription in polyamine-deficient cells but also abolished repression of CDK4 expression induced by ectopic JunD overexpression. ATF-2 silencing also promoted IEC growth in polyamine-depleted cells. These results indicate that induced ATF-2/JunD association following polyamine depletion represses CDK4 transcription, thus contributing to the inhibition of IEC growth.
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Affiliation(s)
- Lan Xiao
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
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Staphylococcal PknB as the first prokaryotic representative of the proline-directed kinases. PLoS One 2010; 5:e9057. [PMID: 20140229 PMCID: PMC2816222 DOI: 10.1371/journal.pone.0009057] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 01/18/2010] [Indexed: 01/25/2023] Open
Abstract
In eukaryotic cell types, virtually all cellular processes are under control of proline-directed kinases and especially MAP kinases. Serine/threonine kinases in general were originally considered as a eukaryote-specific enzyme family. However, recent studies have revealed that orthologues of eukaryotic serine/threonine kinases exist in bacteria. Moreover, various pathogenic species, such as Yersinia and Mycobacterium, require serine/threonine kinases for successful invasion of human host cells. The substrates targeted by bacterial serine/threonine kinases have remained largely unknown. Here we report that the serine/threonine kinase PknB from the important pathogen Staphylococcus aureus is released into the external milieu, which opens up the possibility that PknB does not only phosphorylate bacterial proteins but also proteins of the human host. To identify possible human targets of purified PknB, we studied in vitro phosphorylation of peptide microarrays and detected 68 possible human targets for phosphorylation. These results show that PknB is a proline-directed kinase with MAP kinase-like enzymatic activity. As the potential cellular targets for PknB are involved in apoptosis, immune responses, transport, and metabolism, PknB secretion may help the bacterium to evade intracellular killing and facilitate its growth. In apparent agreement with this notion, phosphorylation of the host-cell response coordinating transcription factor ATF-2 by PknB was confirmed by mass spectrometry. Taken together, our results identify PknB as the first prokaryotic representative of the proline-directed kinase/MAP kinase family of enzymes.
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Abstract
Cooperation among transcription factors is central for their ability to execute specific transcriptional programmes. The AP1 complex exemplifies a network of transcription factors that function in unison under normal circumstances and during the course of tumour development and progression. This Perspective summarizes our current understanding of the changes in members of the AP1 complex and the role of ATF2 as part of this complex in tumorigenesis.
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Affiliation(s)
- Pablo Lopez-Bergami
- Instituto de Biologia y Medicina Experimental, Vuelta de Obligado 2490, Buenos Aires1428, Argentina,
| | - Eric Lau
- Signal Transduction Program, Burnham Institute for Medical Research, La Jolla, CA 92037, USA,
| | - Ze'ev Ronai
- Signal Transduction Program, Burnham Institute for Medical Research, La Jolla, CA 92037, USA
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20
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Brochhausen C, Lehmann M, Halstenberg S, Meurer A, Klaus G, Kirkpatrick CJ. Signalling molecules and growth factors for tissue engineering of cartilage-what can we learn from the growth plate? J Tissue Eng Regen Med 2009; 3:416-29. [DOI: 10.1002/term.192] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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21
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Pejchal J, Österreicher J, Vilasová Z, Tichý A, Vávrová J. Expression of activated ATF-2, CREB and c-Myc in rat colon transversum after whole-body γ-irradiation and its contribution to pathogenesis and biodosimetry. Int J Radiat Biol 2009; 84:315-24. [DOI: 10.1080/09553000801953367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Katoh-Semba R, Kaneko R, Kitajima S, Tsuzuki M, Ichisaka S, Hata Y, Yamada H, Miyazaki N, Takahashi Y, Kato K. Activation of p38 mitogen-activated protein kinase is required for in vivo brain-derived neurotrophic factor production in the rat hippocampus. Neuroscience 2009; 163:352-61. [PMID: 19524026 DOI: 10.1016/j.neuroscience.2009.06.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 04/26/2009] [Accepted: 06/04/2009] [Indexed: 10/20/2022]
Abstract
Several lines of evidence strongly suggest that brain-derived neurotrophic factor (BDNF) is associated with the formation, storage and recall of memory in the hippocampus and that it is important to maintain a considerable level of hippocampal BDNF in order to keep normal functions. BDNF can be synthesized in an activity-dependent manner. In fact, kainic acid or AMPA enhances BDNF levels in hippocampal granule neurons. However, the mechanisms of BDNF production are largely unclear. Recently, we have found that riluzole, which blocks voltage-gated sodium channels and thereby reduces glutamate release, actually strengthens immunoreactivity of BDNF in hippocampal granule neurons of rats. Therefore, we examined the riluzole-activated signaling pathways for BDNF production. Riluzole increased levels of phospho-p38 mitogen-activated protein kinase (p38 MAPK), as well as BDNF levels. Inhibition of p38 MAPK by SB203580 reduced riluzole effects, while activation of p38 MAPK by anisomycin increased levels of BDNF, suggesting that p38 MAPK can mediate BDNF production. Riluzole-induced elevation of phospho-activating transcription factor-2, a transcription factor downstream of p38 MAPK, was also observed. A blocker of N-type voltage-gated calcium channels reduced the effects of riluzole on BDNF production and p38 MAPK activation. We also examined a possible involvement of the adenosine A1 receptor in BDNF production because riluzole can influence ecto-nucleotide levels. An A1 receptor agonist inhibited riluzole-induced elevation of BDNF levels, whereas an antagonist not only increased levels of BDNF and active p38 MAPK but also augmented riluzole effects. These results indicate that, in the rat hippocampus, there is an in vivo signaling pathway for BDNF synthesis mediated by p38 MAPK, and that N-type voltage-gated calcium channels and/or adenosine A1 receptors contribute to p38 MAPK activation.
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Affiliation(s)
- R Katoh-Semba
- Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, 480-0392, Japan.
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Vale-Cruz DS, Ma Q, Syme J, LuValle PA. Activating transcription factor-2 affects skeletal growth by modulating pRb gene expression. Mech Dev 2008; 125:843-56. [DOI: 10.1016/j.mod.2008.06.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 06/17/2008] [Accepted: 06/22/2008] [Indexed: 11/29/2022]
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Karpurapu M, Wang D, Singh NK, Li Q, Rao GN. NFATc1 targets cyclin A in the regulation of vascular smooth muscle cell multiplication during restenosis. J Biol Chem 2008; 283:26577-90. [PMID: 18667424 DOI: 10.1074/jbc.m800423200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Platelet-derived growth factor BB (PDGF-BB) induced cyclin A expression and CDK2 activity in vascular smooth muscle cells (VSMC). Inhibition of nuclear factors of activated T cell (NFAT) activation by cyclosporin A (CsA) and VIVIT suppressed PDGF-BB-induced cyclin A expression and CDK2 activity, resulting in blockade of VSMC in the G(1) phase. In addition, CsA- and VIVIT-mediated inhibition of NFATs and small interfering RNA-targeted down-regulation of cyclin A levels suppressed PDGF-BB-induced VSMC DNA synthesis. PDGF-BB also induced cyclin A mRNA levels in VSMC in an NFAT-dependent manner. Cloning and bioinformatic analysis of rat cyclin A promoter revealed the presence of NFAT-binding elements, and PDGF-BB induced the binding of NFATs to these regulatory sequences in a CsA- and VIVIT-sensitive manner. Chromatin immunoprecipitation analysis showed that NFATc1 binds to the cyclin A promoter in response to PDGF-BB in a VIVIT-sensitive manner. Furthermore, PDGF-BB induced cyclin A promoter-luciferase reporter gene activity in VSMC, and it was inhibited by both CsA and VIVIT. Balloon injury induced cyclin A expression and CDK2 activity in rat carotid arteries, and these responses were also blocked by VIVIT. In addition, VIVIT attenuated balloon injury-induced SMC proliferation, resulting in reduced restenosis. Down-regulation of NFATc1 by its small interfering RNA inhibited PDGF-BB-induced cyclin A expression and DNA synthesis both in rat and human VSMC. Together, these findings demonstrate that the cyclin A-CDK2 complex may be a potential effector of NFATs, specifically NFATc1, in mediating SMC multiplication leading to neointima formation. Therefore, NFATs may be used as target molecules for the development of therapeutic agents against vascular diseases such as restenosis.
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Affiliation(s)
- Manjula Karpurapu
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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Wang IC, Chen YJ, Hughes DE, Ackerson T, Major ML, Kalinichenko VV, Costa RH, Raychaudhuri P, Tyner AL, Lau LF. FoxM1 regulates transcription of JNK1 to promote the G1/S transition and tumor cell invasiveness. J Biol Chem 2008; 283:20770-8. [PMID: 18524773 PMCID: PMC2475715 DOI: 10.1074/jbc.m709892200] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Revised: 06/02/2008] [Indexed: 12/29/2022] Open
Abstract
The Forkhead box M1 (FoxM1) protein is a proliferation-specific transcription factor that plays a key role in controlling both the G(1)/S and G(2)/M transitions through the cell cycle and is essential for the development of various cancers. We show here that FoxM1 directly activates the transcription of the c-Jun N-terminal kinase (JNK1) gene in U2OS osteosarcoma cells. Expression of JNK1, which regulates the expression of genes important for the G(1)/S transition, rescues the G(1)/S but not the G(2)/M cell cycle block in FoxM1-deficient cells. Knockdown of either FoxM1 or JNK1 inhibits tumor cell migration, invasion, and anchorage-independent growth. However, expression of JNK1 in FoxM1-depleted cells does not rescue these defects, indicating that JNK1 is a necessary but insufficient downstream mediator of FoxM1 in these processes. Consistent with this interpretation, FoxM1 regulates the expression of the matrix metalloproteinases MMP-2 and MMP-9, which play a role in tumor cell invasion, through JNK1-independent and -dependent mechanisms in U2OS cells, respectively. Taken together, these findings identify JNK1 as a critical transcriptional target of FoxM1 that contributes to FoxM1-regulated cell cycle progression, tumor cell migration, invasiveness, and anchorage-independent growth.
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Affiliation(s)
- I-Ching Wang
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Yi-Ju Chen
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Douglas E. Hughes
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Timothy Ackerson
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Michael L. Major
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Vladimir V. Kalinichenko
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Robert H. Costa
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Pradip Raychaudhuri
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Angela L. Tyner
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
| | - Lester F. Lau
- Department of Biochemistry and Molecular
Genetics, College of Medicine, University of Illinois at Chicago, Chicago,
Illinois 60607 and the Division of Pulmonary
Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
45229-3039
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26
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Solomon LA, Bérubé NG, Beier F. Transcriptional regulators of chondrocyte hypertrophy. ACTA ACUST UNITED AC 2008; 84:123-30. [DOI: 10.1002/bdrc.20124] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Vlahopoulos SA, Logotheti S, Mikas D, Giarika A, Gorgoulis V, Zoumpourlis V. The role of ATF-2 in oncogenesis. Bioessays 2008; 30:314-27. [PMID: 18348191 DOI: 10.1002/bies.20734] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Activating Transcription Factor-2 is a sequence-specific DNA-binding protein that belongs to the bZIP family of proteins and plays diverse roles in the mammalian cells. In response to stress stimuli, it activates a variety of gene targets including cyclin A, cyclin D and c-jun, which are involved in oncogenesis in various tissue types. ATF-2 expression has been correlated with maintenance of a cancer cell phenotype. However, other studies demonstrate an antiproliferative or apoptotic role for ATF-2. In this review, we summarize the signaling pathways that activate ATF-2, as well as its downstream targets. We examine the role of ATF-2 in carcinogenesis with respect to other bZIP proteins, using data from studies in human cancer cell lines, human tumours and mouse models, and we propose a potential model for its function in carcinogenesis, as well as a theoretical basis for its utility in anticancer drug design.
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Affiliation(s)
- Spiros A Vlahopoulos
- Unit of Biomedical Applications, Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece
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JunB breakdown in mid-/late G2 is required for down-regulation of cyclin A2 levels and proper mitosis. Mol Cell Biol 2008; 28:4173-87. [PMID: 18391017 DOI: 10.1128/mcb.01620-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
JunB, a member of the AP-1 family of dimeric transcription factors, is best known as a cell proliferation inhibitor, a senescence inducer, and a tumor suppressor, although it also has been attributed a cell division-promoting activity. Its effects on the cell cycle have been studied mostly in G1 and S phases, whereas its role in G2 and M phases still is elusive. Using cell synchronization experiments, we show that JunB levels, which are high in S phase, drop during mid- to late G2 phase due to accelerated phosphorylation-dependent degradation by the proteasome. The forced expression of an ectopic JunB protein in late G2 phase indicates that JunB decay is necessary for the subsequent reduction of cyclin A2 levels in prometaphase, the latter event being essential for proper mitosis. Consistently, abnormal JunB expression in late G2 phase entails a variety of mitotic defects. As these aberrations may cause genetic instability, our findings contrast with the acknowledged tumor suppressor activity of JunB and reveal a mechanism by which the deregulation of JunB might contribute to tumorigenesis.
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Taschner MJ, Rafigh M, Lampert F, Schnaiter S, Hartmann C. Ca2+/Calmodulin-dependent kinase II signaling causes skeletal overgrowth and premature chondrocyte maturation. Dev Biol 2008; 317:132-46. [PMID: 18342847 DOI: 10.1016/j.ydbio.2008.02.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 02/01/2008] [Accepted: 02/05/2008] [Indexed: 11/17/2022]
Abstract
The long bones of vertebrate limbs originate from cartilage templates and are formed by the process of endochondral ossification. This process requires that chondrocytes undergo a progressive maturation from proliferating to postmitotic prehypertrophic to mature, hypertrophic chondrocytes. Coordinated control of proliferation and maturation regulates growth of the skeletal elements. Various signals and pathways have been implicated in orchestrating these processes, but the underlying intracellular molecular mechanisms are often not entirely known. Here we demonstrated in the chick using replication-competent retroviruses that constitutive activation of Calcium/Calmodulin-dependent kinase II (CaMKII) in the developing wing resulted in elongation of skeletal elements associated with premature differentiation of chondrocytes. The premature maturation of chondrocytes was a cell-autonomous effect of constitutive CaMKII signaling associated with down-regulation of cell-cycle regulators and up-regulation of chondrocyte maturation markers. In contrast, the elongation of the skeletal elements resulted from a non-cell autonomous up-regulation of the Indian hedgehog responsive gene encoding Parathyroid-hormone-related peptide. Reduction of endogenous CaMKII activity by overexpressing an inhibitory peptide resulted in shortening of the skeletal elements associated with a delay in chondrocyte maturation. Thus, CaMKII is an essential component of intracellular signaling pathways regulating chondrocyte maturation.
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Affiliation(s)
- Michael J Taschner
- Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria
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Chen X, Johnson GS, Schnabel RD, Taylor JF, Johnson GC, Parker HG, Patterson EE, Katz ML, Awano T, Khan S, O'Brien DP. A neonatal encephalopathy with seizures in standard poodle dogs with a missense mutation in the canine ortholog of ATF2. Neurogenetics 2007; 9:41-9. [PMID: 18074159 DOI: 10.1007/s10048-007-0112-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Accepted: 11/24/2007] [Indexed: 12/24/2022]
Abstract
Neonatal encephalopathy with seizures (NEWS) is a previously undescribed autosomal recessive disease of standard poodle puppies. Affected puppies are small and weak at birth. Many die in their first week of life. Those surviving past 1 week develop ataxia, a whole-body tremor, and, by 4 to 6 weeks of age, severe generalized clonic-tonic seizures. None have survived to 7 weeks of age. Cerebella from affected puppies were reduced in size and often contained dysplastic foci consisting of clusters of intermixed granule and Purkinje neurons. We used deoxyribonucleic acid samples from related standard poodles to map the NEWS locus to a 2.87-Mb segment of CFA36, which contains the canine ortholog of ATF2. This gene encodes activating transcription factor 2 (ATF-2), which participates in the cellular responses to a wide variety of stimuli. We amplified and sequenced all coding regions of canine ATF2 from a NEWS-affected puppy and identified a T > G transversion that predicts a methionine-to-arginine missense mutation at amino acid position 51. Methionine-51 lies within a hydrophobic docking site for mitogen-activated protein kinases that activate ATF-2 so the arginine substitution is likely to interfere with ATF-2 activation. All 20 NEWS-affected puppies in the standard poodle family were homozygous for the mutant G allele. The 58 clinically normal family members were either G/T heterozygotes or homozygous for the ancestral T allele. There are no previous reports of spontaneous ATF2 mutations in people or animals; however, atf2-knockout mice have cerebellar lesions that are similar to those in puppies with NEWS.
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Affiliation(s)
- Xuhua Chen
- Department of Veterinary Pathobiology, University of Missouri, 322 Connaway Hall, Columbia, MO, 65211, USA,
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He Z, Jiang J, Kokkinaki M, Golestaneh N, Hofmann MC, Dym M. Gdnf upregulates c-Fos transcription via the Ras/Erk1/2 pathway to promote mouse spermatogonial stem cell proliferation. Stem Cells 2007; 26:266-78. [PMID: 17962702 DOI: 10.1634/stemcells.2007-0436] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) plays a crucial role in regulating the proliferation of spermatogonial stem cells (SSC). The signaling pathways mediating the function of GDNF in SSC remain unclear. This study was designed to determine whether GDNF signals via the Ras/ERK1/2 pathway in the C18-4 cells, a mouse SSC line. The identity of this cell line was confirmed by the expression of various markers for germ cells, proliferating spermatogonia, and SSC, including GCNA1, Vasa, Dazl, PCNA, Oct-4, GFRalpha1, Ret, and Plzf. Western blot analysis revealed that GDNF activated Ret tyrosine phosphorylation. All 3 isoforms of Shc were phosphorylated upon GDNF stimulation, and GDNF induced the binding of the phosphorylated Ret to Shc and Grb2 as indicated by immunoprecipitation and Western blotting. The active Ras was induced by GDNF, which further activated ERK1/2 phosphorylation. GDNF stimulated the phosphorylation of CREB-1, ATF-1, and CREM-1, and c-fos transcription. Notably, the increase in ERK1/2 phosphorylation, c-fos transcription, bromodeoxyuridine incorporation, and metaphase counts induced by GDNF, was completely blocked by pretreatment with PD98059, a specific inhibitor for MEK1, the upstream regulator of ERK1/2. GDNF stimulation eventually upregulated cyclin A and CDK2 expression. Together, these data suggest that GDNF induces CREB/ATF-1 family member phosphorylation and c-fos transcription via the Ras/ERK1/2 pathway to promote the proliferation of SSC. Unveiling GDNF signaling cascades in SSC has important implications in providing attractive targets for male contraception as well as for the regulation of stem cell renewal vs. differentiation.
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Affiliation(s)
- Zuping He
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20057, USA
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Casalino L, Bakiri L, Talotta F, Weitzman JB, Fusco A, Yaniv M, Verde P. Fra-1 promotes growth and survival in RAS-transformed thyroid cells by controlling cyclin A transcription. EMBO J 2007; 26:1878-90. [PMID: 17347653 PMCID: PMC1847654 DOI: 10.1038/sj.emboj.7601617] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Accepted: 01/25/2007] [Indexed: 11/09/2022] Open
Abstract
Fra-1 is frequently overexpressed in epithelial cancers and implicated in invasiveness. We previously showed that Fra-1 plays crucial roles in RAS transformation in rat thyroid cells and mouse fibroblasts. Here, we report a novel role for Fra-1 as a regulator of mitotic progression in RAS-transformed thyroid cells. Fra-1 expression and phosphorylation are regulated during the cell cycle, peaking at G2/M. Knockdown of Fra-1 caused a proliferative block and apoptosis. Although most Fra-1-knockdown cells accumulated in G2, a fraction of cells entering M-phase underwent abortive cell division and exhibited hallmarks of genomic instability (micronuclei, lagging chromosomes and anaphase bridges). Furthermore, we established a link between Fra-1 and the cell-cycle machinery by identifying cyclin A as a novel transcriptional target of Fra-1. During the cell cycle, Fra-1 was recruited to the cyclin A gene (ccna2) promoter, binding to previously unidentified AP-1 sites and the CRE. Fra-1 also induced the expression of JunB, which in turn interacts with the cyclin A promoter. Hence, Fra-1 induction is important in thyroid tumorigenesis, critically regulating cyclin expression and cell-cycle progression.
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Affiliation(s)
- Laura Casalino
- Institute of Genetics and Biophysics ‘A Buzzati Traverso', CNR, Naples, Italy
- Unit of Gene Expression and Disease, Department of Developmental Biology, Pasteur Institute, Paris, France
- Institute of Genetics and Biophysics ‘A Buzzati Traverso', CNR, Naples, Italy. Tel.: +39 0816132452; Fax: +39 0816132706; E-mail:
| | - Latifa Bakiri
- Research Institute of Molecular Pathology, Vienna, Austria
| | - Francesco Talotta
- Institute of Genetics and Biophysics ‘A Buzzati Traverso', CNR, Naples, Italy
| | - Jonathan B Weitzman
- Unit of Gene Expression and Disease, Department of Developmental Biology, Pasteur Institute, Paris, France
| | - Alfredo Fusco
- Department of Molecular and Cellular Pathology, University ‘Federico II', Naples, Italy
| | - Moshe Yaniv
- Unit of Gene Expression and Disease, Department of Developmental Biology, Pasteur Institute, Paris, France
| | - Pasquale Verde
- Institute of Genetics and Biophysics ‘A Buzzati Traverso', CNR, Naples, Italy
- Institute of Genetics and Biophysics ‘A Buzzati Traverso', CNR, Naples, Italy. E-mail:
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Guo L, Sans MD, Gurda GT, Lee SH, Ernst SA, Williams JA. Induction of early response genes in trypsin inhibitor-induced pancreatic growth. Am J Physiol Gastrointest Liver Physiol 2007; 292:G667-77. [PMID: 17095753 DOI: 10.1152/ajpgi.00433.2006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Endogenous CCK release induced by a synthetic trypsin inhibitor, camostat, stimulates pancreatic growth; however, the mechanisms mediating this growth are not well established. Early response genes often couple short-term signals with long-term responses. To study their participation in the pancreatic growth response, mice were fasted for 18 h and refed chow containing 0.1% camostat for 1-24 h. Expression of 18 early response genes were evaluated by quantitative PCR; mRNA for 17 of the 18 increased at 1, 2, 4, or 8 h. Protein expression for c-jun, c-fos, ATF-3, Egr-1, and JunB peaked at 2 h. Nuclear localization was confirmed by immunohistochemistry of c-fos, c-jun, and Egr-1. Refeeding regular chow induced only a small increase of c-jun and none in c-fos expression. JNKs and ERKs were activated 1 h after camostat feeding as was the phosphorylation of c-jun and ATF-2. AP-1 DNA binding evaluated by EMSA showed a significant increase 1-2 h after camostat feeding with participation of c-jun, c-fos, ATF-2, ATF-3, and JunB shown by supershift. The CCK antagonist IQM-95,333 blocked camostat feeding-induced c-jun and c-fos expression by 67 and 84%, respectively, and AP-1 DNA binding was also inhibited. In CCK-deficient mice, the maximal response of c-jun induction and AP-1 DNA binding were reduced by 64 and 70%, respectively. These results indicate that camostat feeding induces a spectrum of early response gene expression and AP-1 DNA binding and that these effects are mainly CCK dependent.
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Affiliation(s)
- Lili Guo
- Dept of Molecular and Integrative Physiology, Univ of Michigan Medical School, Ann Arbor, MI 48109-0622, USA
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Kim ES, Sohn YW, Moon A. TGF-beta-induced transcriptional activation of MMP-2 is mediated by activating transcription factor (ATF)2 in human breast epithelial cells. Cancer Lett 2007; 252:147-56. [PMID: 17258390 DOI: 10.1016/j.canlet.2006.12.016] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 12/14/2006] [Accepted: 12/14/2006] [Indexed: 11/16/2022]
Abstract
We have previously shown that transforming growth factor (TGF)-beta up-regulates matrix metalloproteinase (MMP)-2 leading to the induction of oncogenic signaling in preneoplastic MCF10A human breast epithelial cells. The present study investigated the mechanism of transcriptional regulation of MMP-2 by TGF-beta in MCF10A cells. By using 5' deletion constructs of MMP-2 promoter, we demonstrated that binding sites for p53, S1, AP-1 and Sp1, and to a lesser extent CREB, GCN-His and PEA3, were potential cis-acting elements for TGF-beta-induced transcriptional activation of MMP-2 in MCF10A cells. Since activating transcription factor (ATF)2 was shown to mediate the TGF-beta-induced cellular responses, we examined the involvement of ATF2 in TGF-beta-activated MMP-2 gene transcription. TGF-beta increased DNA binding activity of AP-1 in which ATF2 was involved as evidenced by electrophoretic mobility shift assay. TGF-beta induced phosphorylation of ATF2 through p38 MAPK signaling. A dominant-negative (DN) ATF2 significantly inhibited the TGF-beta-induced up-regulation of MMP-2, but not that of MMP-9, suggesting that ATF2 may be a transcription factor responsible for transcriptional activation of MMP-2 gene by TGF-beta. Invasive and migratory phenotypes induced by TGF-beta were significantly inhibited by DN ATF2, indicating a critical role of ATF2 in TGF-beta-induced oncogenic progression of MCF10A cells. Taken together, this study demonstrates that ATF2 mediates the TGF-beta-induced MMP-2 transcriptional activation, elucidating a molecular mechanism for the malignant progression of human breast epithelial cells exerted by TGF-beta.
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Affiliation(s)
- Eun-Sook Kim
- College of Pharmacy, Duksung Women's University, Seoul 132-714, Republic of Korea
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Ma Q, Li X, Vale-Cruz D, Brown ML, Beier F, LuValle P. Activating transcription factor 2 controls Bcl-2 promoter activity in growth plate chondrocytes. J Cell Biochem 2007; 101:477-87. [PMID: 17219413 DOI: 10.1002/jcb.21198] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Activating transcription factor 2 (ATF-2) is expressed ubiquitously in mammals. Mice deficient in ATF-2 (ATF-2 m/m) are slightly smaller than their normal littermates at birth. Approximately 50% of mice born mutant in both alleles die within the first month. Those that survive develop a hypochondroplasia-like dwarfism, characterized by shortened growth plates and kyphosis. Expression of ATF-2 within the growth plate is limited to the resting and proliferating zones. We have previously shown that ATF-2 targets the cyclic AMP response element (CRE) in the promoters of cyclin A and cyclin D1 in growth plate chondrocytes to activate their expression. Here, we demonstrate that Bcl-2, a cell death inhibitor that regulates apoptosis, is expressed within the growth plate in proliferative and prehypertrophic chondrocytes. However, Bcl-2 expression declines in hypertrophic chondrocytes. The Bcl-2 promoter contains a CRE at -1,552 bp upstream of the translation start. Mutations within this CRE cause reduced Bcl-2 promoter activity. We show here that the absence of ATF-2 in growth plate chondrocytes corresponds to a decline in Bcl-2 promoter activity, as well as a reduction in Bcl-2 protein levels. In addition, we show that ATF-2 as well as CREB, a transcription factor that can heterodimerize with ATF-2, bind to the CRE within the Bcl-2 promoter. These data identify the Bcl-2 gene as a novel target of ATF-2 and CREB in growth plate chondrocytes.
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Affiliation(s)
- Qin Ma
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, FL 32610-0235, USA
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36
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Hoogendam J, Farih-Sips H, van Beek E, Löwik CWGM, Wit JM, Karperien M. Novel late response genes of PTHrP in chondrocytes. HORMONE RESEARCH 2006; 67:159-70. [PMID: 17065821 DOI: 10.1159/000096586] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Accepted: 08/13/2006] [Indexed: 12/13/2022]
Abstract
To gain more insight into the downstream effectors of parathyroid hormone (PTH) related peptide (PTHrP) signaling in chondrocytes, we performed microarray analysis to identify late PTHrP response genes using the chondrogenic ATDC5 cell line and studied their response in the osteoblastic KS483 cell line and explanted metatarsals. At day 8 of micromass culture, ATDC5 cells have pre-hypertrophic-like characteristics and at this time point the cells were stimulated with PTHrP for 24 and 72 h and RNA was isolated. PTHrP treatment inhibited outgrowth of cartilage matrix and decreased the expression of Col10a1 mRNA, which is in line with the inhibitory effects of PTHrP on chondrocyte differentiation. Using cDNA microarray analysis, a list of 9 genes (p< 10(-3)) was generated, including 3 upregulated (IGFBP4, Csrp2, and Ecm1) and 6 downregulated (Col9a1, Col2a1, Agc, Hmgn2, Calm1, and Mxd4) response genes. Four out of 9 genes are novel PTHrP response genes and 2 out of 9 have not yet been identified in cartilage. Four out of 9 genes are components of the extra-cellular matrix and the remaining genes are involved in signal transduction and transcription regulation. The response to PTHrP was validated by quantitative PCR, using the same RNA samples as labeled in the microarray experiments and RNA samples isolated from a new experiment. In addition, we examined whether these genes also reacted to PTHrP in other PTHrP responsive models, like KS483 osteoblasts and explanted metatarsals. The expression of late PTHrP response genes varied between ATDC5 chondrocytes, KS483 osteoblasts and metatarsals, suggesting that the expression of late response genes is dependent on the cellular context of the PTHrP responsive cells.
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Affiliation(s)
- Jakomijn Hoogendam
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
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James CG, Woods A, Underhill TM, Beier F. The transcription factor ATF3 is upregulated during chondrocyte differentiation and represses cyclin D1 and A gene transcription. BMC Mol Biol 2006; 7:30. [PMID: 16984628 PMCID: PMC1584246 DOI: 10.1186/1471-2199-7-30] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Accepted: 09/19/2006] [Indexed: 11/14/2022] Open
Abstract
Background Coordinated chondrocyte proliferation and differentiation are required for normal endochondral bone growth. Transcription factors binding to the cyclicAMP response element (CRE) are known to regulate these processes. One member of this family, Activating Tanscription Factor 3 (ATF3), is expressed during skeletogenesis and acts as a transcriptional repressor, but the function of this protein in chondrogenesis is unknown. Results Here we demonstrate that Atf3 mRNA levels increase during mouse chondrocyte differentiation in vitro and in vivo. In addition, Atf3 mRNA levels are increased in response to cytochalasin D treatment, an inducer of chondrocyte maturation. This is accompanied by increased Atf3 promoter activity in cytochalasin D-treated chondrocytes. We had shown earlier that transcription of the cell cycle genes cyclin D1 and cyclin A in chondrocytes is dependent on CREs. Here we demonstrate that overexpression of ATF3 in primary mouse chondrocytes results in reduced transcription of both genes, as well as decreased activity of a CRE reporter plasmid. Repression of cyclin A transcription by ATF3 required the CRE in the cyclin A promoter. In parallel, ATF3 overexpression reduces the activity of a SOX9-dependent promoter and increases the activity of a RUNX2-dependent promoter. Conclusion Our data suggest that transcriptional induction of the Atf3 gene in maturing chondrocytes results in down-regulation of cyclin D1 and cyclin A expression as well as activation of RUNX2-dependent transcription. Therefore, ATF3 induction appears to facilitate cell cycle exit and terminal differentiation of chondrocytes.
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Affiliation(s)
- Claudine G James
- CIHR Group in Skeletal Development and Remodeling, University of Western Ontario, London, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Anita Woods
- CIHR Group in Skeletal Development and Remodeling, University of Western Ontario, London, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - T Michael Underhill
- CIHR Group in Skeletal Development and Remodeling, University of Western Ontario, London, ON, Canada
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Frank Beier
- CIHR Group in Skeletal Development and Remodeling, University of Western Ontario, London, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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McMullen NM, Gaspard GJ, Pasumarthi KBS. Reactivation of cardiomyocyte cell cycle: A potential approach for myocardial regeneration. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/sita.200400050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Abstract
The AP-1 transcription factor is mainly composed of Jun, Fos and ATF protein dimers. It mediates gene regulation in response to a plethora of physiological and pathological stimuli, including cytokines, growth factors, stress signals, bacterial and viral infections, as well as oncogenic stimuli. Studies in genetically modified mice and cells have highlighted a crucial role for AP-1 in a variety of cellular events involved in normal development or neoplastic transformation causing cancer. However, emerging evidence indicates that the contribution of AP-1 to determination of cell fates critically depends on the relative abundance of AP-1 subunits, the composition of AP-1 dimers, the quality of stimulus, the cell type and the cellular environment. Therefore, AP-1-mediated regulation of processes such as proliferation, differentiation, apoptosis and transformation should be considered within the context of a complex dynamic network of signalling pathways and other nuclear factors that respond simultaneously.
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Affiliation(s)
- Jochen Hess
- Deutsches Krebsforschungszentrum, Division of Signal Transduction and Growth Control, 69120 Heidelberg, Germany
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Inada A, Weir GC, Bonner-Weir S. Induced ICER Iγ down-regulates cyclin A expression and cell proliferation in insulin-producing β cells. Biochem Biophys Res Commun 2005; 329:925-9. [PMID: 15752744 DOI: 10.1016/j.bbrc.2005.02.046] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Indexed: 10/25/2022]
Abstract
We have previously found that cyclin A expression is markedly reduced in pancreatic beta-cells by cell-specific overexpression of repressor inducible cyclic AMP early repressor (ICER Igamma) in transgenic mice. Here we further examined regulatory effects of ICER Igamma on cyclin A gene expression using Min6 cells, an insulin-producing cell line. The cyclin A promoter luciferase assay showed that ICER Igamma directly repressed cyclin A gene transcription. In addition, upon ICER Igamma overexpression, cyclin A mRNA levels markedly decreased, thereby confirming an inhibitory effect of ICER Igamma on cyclin A expression. Suppression of cyclin A results in inhibition of BrdU incorporation. Under normal culture conditions endogenous cyclin A is abundant in these cells, whereas ICER is hardly detectable. However, serum starvation of Min6 cells induces ICER Igamma expression with a concomitant very low expression level of cyclin A. Cyclin A protein is not expressed unless the cells are in active DNA replication. These results indicate a potentially important anti-proliferative effect of ICER Igamma in pancreatic beta cells. Since ICER Igamma is greatly increased in diabetes as well as in FFA- or high glucose-treated islets, this effect may in part exacerbate diabetes by limiting beta-cell proliferation.
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Affiliation(s)
- Akari Inada
- Section of Islet Transplantation and Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
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41
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Katabami M, Donninger H, Hommura F, Leaner VD, Kinoshita I, Chick JFB, Birrer MJ. Cyclin A is a c-Jun target gene and is necessary for c-Jun-induced anchorage-independent growth in RAT1a cells. J Biol Chem 2005; 280:16728-38. [PMID: 15737994 DOI: 10.1074/jbc.m413892200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Overexpression of c-Jun enables Rat1a cells to grow in an anchorage-independent manner. We used an inducible c-Jun system under the regulation of doxycycline in Rat1a cells to identify potential c-Jun target genes necessary for c-Jun-induced anchorage-independent growth. Induction of c-Jun results in sustained expression of cyclin A in the nonadherent state with only minimal expression in the absence of c-Jun. The promoter activity of cyclin A2 was 4-fold higher in Rat1a cells in which c-Jun expression was induced compared with the control cells. Chromatin immunoprecipitation demonstrated that c-Jun bound directly to the cyclin A2 promoter. Mutation analysis of the cyclin A2 promoter mapped the c-Jun regulatory site to an ATF site at position -80. c-Jun was able to bind to this site both in vitro and in vivo, and mutation of this site completely abolished promoter activity. Cyclin A1 was also elevated in c-Jun-overexpressing Rat1a cells; however, c-Jun did not regulate this gene directly, since it did not bind directly to the cyclin A1 promoter. Suppression of cyclin A expression via the introduction of a cyclin A antisense sequences significantly reduced the ability of c-Jun-overexpressing Rat1a cells to grow in an anchorage-independent fashion. Taken together, these results suggest that cyclin A is a target of c-Jun and is necessary but not sufficient for c-Jun-induced anchorage-independent growth. In addition, we demonstrated that the cytoplasmic oncogenes Ras and Src transcriptionally activated the cyclin A2 promoter via the ATF site at position -80. Using a dominant negative c-Jun mutant, TAM67, we showed that this transcriptional activation of cyclin A2 requires c-Jun. Thus, our results suggest that c-Jun is a mediator of the aberrant cyclin A2 expression associated with Ras/Src-induced transformation.
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Affiliation(s)
- Motoo Katabami
- Department of Cell and Cancer Biology, NCI, National Institutes of Health, Rockville, Maryland 20850, USA
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Pearson AG, Curtis MA, Waldvogel HJ, Faull RLM, Dragunow M. Activating transcription factor 2 expression in the adult human brain: Association with both neurodegeneration and neurogenesis. Neuroscience 2005; 133:437-51. [PMID: 15878807 DOI: 10.1016/j.neuroscience.2005.02.029] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2004] [Revised: 02/15/2005] [Accepted: 02/20/2005] [Indexed: 11/23/2022]
Abstract
Activating transcription factor 2 (ATF2) is a member of the activator protein-1 family of transcription factors, which includes c-Jun and c-Fos. ATF2 is highly expressed in the mammalian brain although little is known about its function in nerve cells. Knockout mouse studies show that this transcription factor plays a role in neuronal migration during development but over-expression of ATF2 in neuronal-like cell culture promotes nerve cell death. Using immunohistochemical techniques we demonstrate ATF2 expression in the normal human brain is neuronal, is found throughout the cerebral cortex and is particularly high in the granule cells of the hippocampus, in the brain stem, in the pigmented cells of the substantia nigra and locus coeruleus, and in the granule and molecular cell layers of the cerebellum. In contrast to normal cases, ATF2 expression is down-regulated in the hippocampus, substantia nigra pars compacta and caudate nucleus of the neurological diseases Alzheimer's, Parkinson's and Huntington's, respectively. Paradoxically, an increase in ATF2 expression was found in the subependymal layer of Huntington's disease cases, compared with normal brains; a region reported to contain increased numbers of proliferating progenitor cells in Huntington's disease. We propose ATF2 plays a role in neuronal viability in the normal brain, which is compromised in susceptible regions of neurological diseases leading to its down-regulation. In contrast, the increased expression of ATF2 in the subependymal layer of Huntington's disease suggests a role for ATF2 in some aspect of neurogenesis in the diseased brain.
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Affiliation(s)
- A G Pearson
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
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Halawani D, Mondeh R, Stanton LA, Beier F. p38 MAP kinase signaling is necessary for rat chondrosarcoma cell proliferation. Oncogene 2004; 23:3726-31. [PMID: 15116104 DOI: 10.1038/sj.onc.1207422] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chondrosarcomas represent the second most frequent class of primary skeletal malignancies. This tumor type is highly resistant to radiation therapy and currently available chemotherapies, thereby limiting treatment choice to surgical resection. Identifying the mechanisms responsible for chondrosarcoma cell proliferation is therefore crucial for the development of new treatment strategies. Here, we demonstrate a significant reduction in rat chondrosarcoma cell proliferation following treatment with pharmacological inhibitors (SB202190 and PD169316) of p38 mitogen-activated protein (MAP) kinases. In an attempt to dissect possible mechanisms, we investigated the effect of p38 inhibition on promoter activity of cell-cycle genes. Surprisingly, p38 inhibition resulted in upregulation of the activities of all three D-type cyclin promoters. In addition, p38 inhibitors induced increased transcription of the cell-cycle inhibitor p21(waf1/cip1). As expected, promoter activity of the cyclin A gene, which lies downstream of D-type cyclins and p21 in cell-cycle progression, was strongly reduced by p38 inhibitors. These effects were independent of a cyclic AMP response element and conferred by the proximal 150 nucleotides of the cyclin A promoter. Decreased transcription was accompanied by greatly reduced cyclin A protein levels upon p38 inhibition. These observations indicate complex regulation of chondrosarcoma cell-cycle progression by p38 signaling, and suggest that components of p38 MAP kinase pathways may be effective targets in the treatment of these tumors.
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Affiliation(s)
- Dalia Halawani
- Department of Physiology and Pharmacology, Canadian Institute of Health Research Group in Skeletal Development and Remodeling, University of Western Ontario, London, Ontario, Canada N6A 5C1
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Stanton LA, Sabari S, Sampaio AV, Underhill TM, Beier F. p38 MAP kinase signalling is required for hypertrophic chondrocyte differentiation. Biochem J 2004; 378:53-62. [PMID: 14594450 PMCID: PMC1223932 DOI: 10.1042/bj20030874] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2003] [Revised: 10/08/2003] [Accepted: 10/31/2003] [Indexed: 01/19/2023]
Abstract
Longitudinal growth of endochondral bones is accomplished through the co-ordinated proliferation and hypertrophic differentiation of growth plate chondrocytes. The molecular mechanisms and signalling cascades controlling these processes are not well understood. To analyse the expression and roles of p38 mitogen-activated protein kinases in this process, we have established a micromass system for the reproducible hypertrophic differentiation of mouse mesenchymal limb bud cells. Our results show that all four mammalian p38 kinase genes are expressed during the chondrogenic programme, as well as their upstream regulators MKK3 (mitogen-activated protein kinase kinase 3) and MKK6. Treatment of micromass cultures with pharmacological inhibitors of p38 results in a marked delay in hypertrophic differentiation in micromass cultures, indicating a requirement for p38 signalling in chondrocyte differentiation. Inhibition of p38 kinase activity leads to reduced and delayed induction of alkaline phosphatase activity and matrix mineralization. In addition, p38 inhibition causes reduced expression of hypertrophic marker genes such as collagen X, matrix metalloproteinase 13 and bone sialoprotein. The function of p38 in hypertrophic differentiation appears to be mediated, at least in part, by the transcription factor myocyte enhancer factor 2C. In summary, we have demonstrated a novel requirement for p38 signalling in hypertrophic differentiation of chondrocytes and identified myocyte enhancer factor 2C as an important regulator of chondrocyte gene expression.
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Affiliation(s)
- Lee-Anne Stanton
- CHIR Group in Skeletal Development and Remodeling, Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada N6A 5C1
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Abstract
The longitudinal growth of endochondral bones is governed by proliferation and hypertrophic differentiation of growth plate chondrocytes. Numerous growth factors and hormones have been implicated in the regulation of these processes, but the intracellular mechanisms involved remain much less understood. We had suggested a role of cell-cycle genes in the integration of these diverse extracellular signals and their translation into coordinated proliferation and differentiation of chondrocytes. Numerous recent studies have provided support for such a scenario and provide novel insights into the regulation and function of cell-cycle genes in chondrocytes. This review article summarizes recent progress in the field.
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Affiliation(s)
- Frank Beier
- CIHR Group in Skeletal Development and Remodeling, Department of Physiology and Pharmacology, and School of Dentistry, University of Western Ontario, London, Ontario, Canada.
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46
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Sunters A, Thomas DP, Yeudall WA, Grigoriadis AE. Accelerated cell cycle progression in osteoblasts overexpressing the c-fos proto-oncogene: induction of cyclin A and enhanced CDK2 activity. J Biol Chem 2003; 279:9882-91. [PMID: 14699150 DOI: 10.1074/jbc.m310184200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Transgenic mice overexpressing the c-Fos oncoprotein develop osteosarcomas that are associated with deregulated expression of cell cycle genes. Here we have generated osteoblast cell lines expressing c-fos under the control of a tetracycline-regulatable promoter to investigate the role of c-Fos in osteoblast cell cycle control in vitro. Three stable subclones, AT9.2, AT9.3, and AT9.7, derived from MC3T3-E1 mouse osteoblasts, expressed high levels of exogenous c-fos mRNA and protein in the absence of tetracycline. Functional contribution of ectopic c-Fos to AP-1 complexes was confirmed by electromobility shift assays and transactivation of AP-1 reporter constructs. Induction of exogenous c-Fos in quiescent AT9.2 cells caused accelerated S-phase entry following serum stimulation, resulting in enhanced growth rate. Ectopic c-Fos resulted in increased expression of cyclins A and E protein levels, and premature activation of cyclin A-, cyclin E-, and cyclin-dependent kinase (CDK) 2-associated kinase activities, although cyclin D levels and CDK4 activity were not affected significantly in these cell lines. The enhanced CDK2 kinase activity was associated with a rapid, concomitant dissociation of p27 from CDK2-containing complexes. Deregulated cyclin A expression and CDK2 activity was also observed in primary mouse osteoblasts overexpressing c-Fos, but not in fibroblasts, and c-Fos transgenic tumor-derived osteosarcoma cells constitutively expressed high levels of cyclin A protein. These data suggest that overexpression of c-Fos in osteoblasts results in accelerated S phase entry as a result of deregulated cyclin A/E-CDK2 activity. This represents a novel role for c-Fos in osteoblast growth control and may provide c-Fos-overexpressing osteoblasts with a growth advantage during tumorigenesis.
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Affiliation(s)
- Andrew Sunters
- Department of Craniofacial Development, King's College London, Guy's Hospital, Guy's Tower, United Kingdom
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Hess J, Hartenstein B, Teurich S, Schmidt D, Schorpp-Kistner M, Angel P. Defective endochondral ossification in mice with strongly compromised expression of JunB. J Cell Sci 2003; 116:4587-96. [PMID: 14576352 DOI: 10.1242/jcs.00772] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Functional analysis in mice has established an absolute requirement of JunB, a member of the AP-1 transcription factor family, during early embryonic development. To investigate the role of JunB during mid and late gestation and postnatally Ubi-junB transgenic mice were used to generate two junB–/– Ubi-junB mutant lines, in which embryonic lethality was rescued but strongly reduced JunB expression in several adult tissues was observed. Mutant mice from both rescue lines were growth retarded and shared significantly reduced longitudinal bone growth. Mutant long bones were characterised by reduced numbers of growth plate chondrocytes and a severe osteoporosis. Decreased JunB levels in epiphysal growth plate chondrocytes and bone lining osteoblasts correlated with deregulated expression of Cyclin A, Cyclin D1 and p16INK4a, key regulators of cell cycle control. Furthermore, junB–/– Ubi-junB bone marrow stromal cells were unable to differentiate into bone forming osteoblasts in vitro. Our data demonstrate that JunB plays a crucial role in endochondral ossification by regulating proliferation and function of chondrocytes and osteoblasts.
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Affiliation(s)
- Jochen Hess
- Deutsches Krebsforschungszentrum Heidelberg (DKFZ), Division of Signal Transduction and Growth Control (A100), Im Neuenheimer Feld 280, D-69120 Heidelberg
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Paruchuri S, Sjölander A. Leukotriene D4 mediates survival and proliferation via separate but parallel pathways in the human intestinal epithelial cell line Int 407. J Biol Chem 2003; 278:45577-85. [PMID: 12912998 DOI: 10.1074/jbc.m302881200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We demonstrated previously that leukotriene D4 (LTD4) regulates proliferation of intestinal epithelial cells through a CysLT receptor by protein kinase C (PKC)epsilon-dependent stimulation of the mitogen-activated protein kinase ERK1/2. Our current study provides the first evidence that LTD4 can activate 90-kDa ribosomal S6 kinase (p90RSK) and cAMP-responsive element-binding protein (CREB) via pertussis-toxin-sensitive Gi protein pathways. Transfection and inhibitor experiments revealed that activation of p90RSK, but not CREB, is a PKCepsilon/Raf-1/ERK1/2-dependent process. LTD4-mediated CREB activation was not affected by expression of kinase-dead p90RSK but was abolished by transfection with the regulatory domain of PKCalpha (a specific dominant-inhibitor of PKCalpha). Kinase-negative mutants of p90RSK and CREB (K-p90RSK and K-CREB) blocked the LTD4-induced increase in cell number and DNA synthesis (thymidine incorporation). Compatible with these results, flow cytometry showed that LTD4 caused transition from the G0/G1 to the S+G2/M cell cycle phase, indicating increased proliferation. Similar treatment of cells transfected with K-p90RSK resulted in cell cycle arrest in the G0/G1 phase, consistent with a role of p90RSK in LTD4-induced proliferation. On the other hand, expression of K-CREB caused a substantial buildup in the sub-G0/G1 phase, suggesting a role for CREB in mediating LTD4-mediated survival in intestinal epithelial cells. Our results show that LTD4 regulates proliferation and survival via distinct intracellular signaling pathways in intestinal epithelial cells.
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Affiliation(s)
- Sailaja Paruchuri
- Division of Experimental Pathology, Department of Laboratory Medicine, Lund University, University Hospital Malmö, Malmö SE-205 02, Sweden
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Abstract
The majority of the vertebrate skeleton develops through the process of endochondral ossification and involves successive steps of chondrogenesis, chondrocyte proliferation, and hypertrophic chondrocyte differentiation. Interruption of this program through gene mutations and hormonal or environmental factors contributes to numerous diseases, including growth disorders and chondrodysplasias. While a large number of growth factors and hormones have been implicated in the regulation of chondrocyte biology, relatively little is known about the intracellular signaling pathways involved. Recent data provide novel insights into the mechanisms governing acquisition of new phenotypes within the chondrogenic program and suggest multiple pivotal roles for members of the mitogen-activated protein kinase family and their downstream targets in cartilage development. These data are summarized and discussed here.
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Affiliation(s)
- Lee-Anne Stanton
- CIHR Group in Skeletal Development and Remodeling, Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
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Luvalle P, Ma Q, Beier F. The role of activating transcription factor-2 in skeletal growth control. J Bone Joint Surg Am 2003; 85-A Suppl 2:133-6. [PMID: 12721356 DOI: 10.2106/00004623-200300002-00018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Phyllis Luvalle
- Department of Anatomy and Cell Biology, University of Florida, Gainesville 32610, USA.
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