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Sun J, Zhang Y, Zhang Q, Hu L, Zhao L, Wang H, Yuan Y, Niu H, Wang D, Zhang H, Liu J, Feng X, Su X, Qiu J, Sun J, Xu H, Zhang C, Wang K, Bi Y, Engleman EG, Shen L. Metabolic regulator LKB1 controls adipose tissue ILC2 PD-1 expression and mitochondrial homeostasis to prevent insulin resistance. Immunity 2024:S1074-7613(24)00229-2. [PMID: 38772366 DOI: 10.1016/j.immuni.2024.04.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 02/06/2024] [Accepted: 04/25/2024] [Indexed: 05/23/2024]
Abstract
Adipose tissue group 2 innate lymphoid cells (ILC2s) help maintain metabolic homeostasis by sustaining type 2 immunity and promoting adipose beiging. Although impairment of the ILC2 compartment contributes to obesity-associated insulin resistance, the underlying mechanisms have not been elucidated. Here, we found that ILC2s in obese mice and humans exhibited impaired liver kinase B1 (LKB1) activation. Genetic ablation of LKB1 disrupted ILC2 mitochondrial metabolism and suppressed ILC2 responses, resulting in exacerbated insulin resistance. Mechanistically, LKB1 deficiency induced aberrant PD-1 expression through activation of NFAT, which in turn enhanced mitophagy by suppressing Bcl-xL expression. Blockade of PD-1 restored the normal functions of ILC2s and reversed obesity-induced insulin resistance in mice. Collectively, these data present the LKB1-PD-1 axis as a promising therapeutic target for the treatment of metabolic disease.
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Affiliation(s)
- Jiping Sun
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Youqin Zhang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Qingbing Zhang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Lin Hu
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Linfeng Zhao
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hongdong Wang
- Department of Endocrinology, Drum Tower Hospital affiliated with Nanjing University Medical School, Branch of National Clinical Research Centre for Metabolic Diseases, Nanjing 210008, China
| | - Yue Yuan
- Department of Endocrinology, Drum Tower Hospital affiliated with Nanjing University Medical School, Branch of National Clinical Research Centre for Metabolic Diseases, Nanjing 210008, China
| | - Hongshen Niu
- Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Dongdi Wang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huasheng Zhang
- Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jianyue Liu
- Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xujiao Feng
- Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaohui Su
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ju Qiu
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jing Sun
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Heping Xu
- Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China
| | - Catherine Zhang
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Kathleen Wang
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Yan Bi
- Department of Endocrinology, Drum Tower Hospital affiliated with Nanjing University Medical School, Branch of National Clinical Research Centre for Metabolic Diseases, Nanjing 210008, China
| | - Edgar G Engleman
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Lei Shen
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
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Niu H, Zhang H, Wang D, Zhao L, Zhang Y, Zhou W, Zhang J, Su X, Sun J, Su B, Qiu J, Shen L. LKB1 prevents ILC2 exhaustion to enhance antitumor immunity. Cell Rep 2024:113579. [PMID: 38670109 DOI: 10.1016/j.celrep.2023.113579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 06/23/2023] [Accepted: 11/29/2023] [Indexed: 04/28/2024] Open
Abstract
Group 2 innate lymphoid cells (ILC2s) play crucial roles in mediating allergic inflammation. Recent studies also indicate their involvement in regulating tumor immunity. The tumor suppressor liver kinase B1 (LKB1) inactivating mutations are associated with a variety of human cancers; however, the role of LKB1 in ILC2 function and ILC2-mediated tumor immunity remains unknown. Here, we show that ablation of LKB1 in ILC2s results in an exhausted-like phenotype, which promotes the development of lung melanoma metastasis. Mechanistically, LKB1 deficiency leads to a marked increase in the expression of programmed cell death protein-1 (PD-1) in ILC2s through the activation of the nuclear factor of activated T cell pathway. Blockade of PD-1 can restore the effector functions of LKB1-deficient ILC2s, leading to enhanced antitumor immune responses in vivo. Together, our results reveal that LKB1 acts to restrain the exhausted state of ILC2 to maintain immune homeostasis and antitumor immunity.
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Affiliation(s)
- Hongshen Niu
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huasheng Zhang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Dongdi Wang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Linfeng Zhao
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Youqin Zhang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wenyong Zhou
- Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Jingjing Zhang
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaohui Su
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jiping Sun
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Bing Su
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Ju Qiu
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Lei Shen
- Center for Immune-Related Diseases at Shanghai Institute of Immunology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Department of Immunology and Microbiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
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Zhao Q, Liu Z, Song P, Yuan Z, Zou MH. Mitochondria-derived Vesicle Packaging as a Novel Therapeutic Mechanism in Pulmonary Hypertension. Am J Respir Cell Mol Biol 2024; 70:39-49. [PMID: 37713305 PMCID: PMC10768832 DOI: 10.1165/rcmb.2023-0010oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 09/14/2023] [Indexed: 09/17/2023] Open
Abstract
Increasing evidence suggests that mitochondrial dysfunction in pulmonary endothelial cells (ECs) plays a causative role in the initiation and progression of pulmonary hypertension (PH); how mitochondria become dysfunctional in PH remains elusive. Mitochondria-derived vesicles (MDVs) are small subcellular vesicles that excise from mitochondria. Whether MDV deregulation causes mitochondrial dysfunction in PH is unknown. The aim of this study was to determine MDV regulation in ECs and to elucidate how MDV deregulation in ECs leads to PH. MDV formation and mitochondrial morphology/dynamics were examined in ECs of EC-specific liver kinase B1 (LKB1) knockout mice (LKB1ec-/-), in monocrotaline-induced PH rats, and in lungs of patients with PH. Pulmonary ECs of patients with PH and hypoxia-treated pulmonary ECs exhibited increased mitochondrial fragmentation and disorganized mitochondrial ultrastructure characterized by electron lucent-swelling matrix compartments and concentric layering of the cristae network, together with defective MDV shedding. MDVs actively regulated mitochondrial membrane dynamics and mitochondrial ultrastructure via removing mitofission-related cargoes. The shedding of MDVs from parental mitochondria required LKB1-mediated mitochondrial recruitment of Rab9 GTPase. LKB1ec-/- mice spontaneously developed PH with decreased mitochondrial pools of Rab9 GTPase, defective MDV shedding, and disequilibrium of the mitochondrial fusion-fission cycle in pulmonary ECs. Aerosol intratracheal delivery of adeno-associated virus LKB1 reversed PH, together with improved MDV shedding and mitochondrial function in rats in vivo. We conclude that LKB1 regulates MDV shedding and mitochondrial dynamics in pulmonary ECs by enhancing mitochondrial recruitment of Rab9 GTPase. Defects of LKB1-mediated MDV shedding from parental mitochondria instigate EC dysfunction and PH.
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Affiliation(s)
- Qiang Zhao
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, Georgia; and
- Department of Cardiology, The First Affiliated Hospital of Xian Jiaotong University, Xi’an, Shaanxi, China
| | - Zhixue Liu
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, Georgia; and
| | - Ping Song
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, Georgia; and
| | - Zuyi Yuan
- Department of Cardiology, The First Affiliated Hospital of Xian Jiaotong University, Xi’an, Shaanxi, China
| | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, Georgia; and
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4
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Fang KT, Hung H, Lau NYS, Chi JH, Wu DC, Cheng KH. Development of a Genetically Engineered Mouse Model Recapitulating LKB1 and PTEN Deficiency in Gastric Cancer Pathogenesis. Cancers (Basel) 2023; 15:5893. [PMID: 38136437 PMCID: PMC10741874 DOI: 10.3390/cancers15245893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/12/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023] Open
Abstract
The LKB1 and PTEN genes are critical in gastric cancer (G.C.) development. LKB1, a robust tumor suppressor gene, encodes a serine/threonine kinase that directly triggers the activation of AMPK-an integral cellular metabolic kinase. The role of the LKB1 pathway extends to maintaining the stability of epithelial junctions by regulating E-cadherin expression. Conversely, PTEN, a frequently mutated tumor suppressor gene in various human cancers, emerges as a pivotal negative regulator of the phosphoinositide 3-kinase (PI3K) signaling pathway. This study is set to leverage the H+/K+ ATPase Cre transgene strain to precisely target Cre recombinase expression at parietal cells within the stomach. This strategic maneuver seeks to selectively nullify the functions of both LKB1 and PTEN in a manner specific to the stomach, thereby instigating the development of G.C. in a fashion akin to human gastric adenocarcinoma. Moreover, this study endeavors to dissect the intricate ways in which these alterations contribute to the histopathologic advancement of gastric tumors, their potential for invasiveness and metastasis, their angiogenesis, and the evolving tumor stromal microenvironment. Our results show that conditional deletion of PTEN and LKB1 provides an ideal cancer microenvironment for G.C. tumorigenesis by promoting cancer cell proliferation, angiogenesis, and metastasis.
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Affiliation(s)
- Kuan-Te Fang
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan; (K.-T.F.); (H.H.); (N.Y.S.L.); (J.-H.C.)
| | - Hsin Hung
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan; (K.-T.F.); (H.H.); (N.Y.S.L.); (J.-H.C.)
| | - Nga Yin Sadonna Lau
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan; (K.-T.F.); (H.H.); (N.Y.S.L.); (J.-H.C.)
- Center of Excellence for Metabolic Associated Fatty Liver Disease, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
| | - Jou-Hsi Chi
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan; (K.-T.F.); (H.H.); (N.Y.S.L.); (J.-H.C.)
- Center of Excellence for Metabolic Associated Fatty Liver Disease, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
| | - Deng-Chyang Wu
- Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Kuang-Hung Cheng
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan; (K.-T.F.); (H.H.); (N.Y.S.L.); (J.-H.C.)
- Center of Excellence for Metabolic Associated Fatty Liver Disease, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- National Institute of Cancer Research, National Health Research Institutes, Tainan 70456, Taiwan
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5
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Compton SE, Kitchen-Goosen SM, DeCamp LM, Lau KH, Mabvakure B, Vos M, Williams KS, Wong KK, Shi X, Rothbart SB, Krawczyk CM, Jones RG. LKB1 controls inflammatory potential through CRTC2-dependent histone acetylation. Mol Cell 2023:S1097-2765(23)00288-5. [PMID: 37172591 DOI: 10.1016/j.molcel.2023.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/17/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023]
Abstract
Deregulated inflammation is a critical feature driving the progression of tumors harboring mutations in the liver kinase B1 (LKB1), yet the mechanisms linking LKB1 mutations to deregulated inflammation remain undefined. Here, we identify deregulated signaling by CREB-regulated transcription coactivator 2 (CRTC2) as an epigenetic driver of inflammatory potential downstream of LKB1 loss. We demonstrate that LKB1 mutations sensitize both transformed and non-transformed cells to diverse inflammatory stimuli, promoting heightened cytokine and chemokine production. LKB1 loss triggers elevated CRTC2-CREB signaling downstream of the salt-inducible kinases (SIKs), increasing inflammatory gene expression in LKB1-deficient cells. Mechanistically, CRTC2 cooperates with the histone acetyltransferases CBP/p300 to deposit histone acetylation marks associated with active transcription (i.e., H3K27ac) at inflammatory gene loci, promoting cytokine expression. Together, our data reveal a previously undefined anti-inflammatory program, regulated by LKB1 and reinforced through CRTC2-dependent histone modification signaling, that links metabolic and epigenetic states to cell-intrinsic inflammatory potential.
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Affiliation(s)
- Shelby E Compton
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA
| | - Susan M Kitchen-Goosen
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA; Metabolism and Nutrition (MeNu) Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Lisa M DeCamp
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA; Metabolism and Nutrition (MeNu) Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Kin H Lau
- Bioinformatics and Biostatistics Core, Van Andel Institute, Grand Rapids, MI, USA
| | - Batsirai Mabvakure
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA
| | - Matthew Vos
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA; Metabolism and Nutrition (MeNu) Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Kelsey S Williams
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA; Metabolism and Nutrition (MeNu) Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Kwok-Kin Wong
- Laura and Isaac Perlmutter Cancer Center, NYU Langone Health, New York, NY, USA
| | - Xiaobing Shi
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, USA
| | - Scott B Rothbart
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, USA
| | - Connie M Krawczyk
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA; Metabolism and Nutrition (MeNu) Program, Van Andel Institute, Grand Rapids, MI, USA
| | - Russell G Jones
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI, USA; Metabolism and Nutrition (MeNu) Program, Van Andel Institute, Grand Rapids, MI, USA.
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Huang E, Li S. Liver Kinase B1 Functions as a Regulator for Neural Development and a Therapeutic Target for Neural Repair. Cells 2022; 11:cells11182861. [PMID: 36139438 PMCID: PMC9496952 DOI: 10.3390/cells11182861] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/02/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
The liver kinase B1 (LKB1), also known as serine/threonine kinase 11 (STK11) and Par-4 in C. elegans, has been identified as a master kinase of AMPKs and AMPK-related kinases. LKB1 plays a crucial role in cell growth, metabolism, polarity, and tumor suppression. By interacting with the downstream signals of SAD, NUAK, MARK, and other kinases, LKB1 is critical to regulating neuronal polarization and axon branching during development. It also regulates Schwann cell function and the myelination of peripheral axons. Regulating LKB1 activity has become an attractive strategy for repairing an injured nervous system. LKB1 upregulation enhances the regenerative capacity of adult CNS neurons and the recovery of locomotor function in adult rodents with CNS axon injury. Here, we update the major cellular and molecular mechanisms of LKB1 in regulating neuronal polarization and neural development, and the implications thereof for promoting neural repair, axon regeneration, and functional recovery in adult mammals.
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7
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Zhou Y, Zhang Y, Li Y, Liu L, Li Z, Liu Y, Xiao Y. MicroRNA-106a-5p promotes the proliferation, autophagy and migration of lung adenocarcinoma cells by targeting LKB1/AMPK. Exp Ther Med 2021; 22:1422. [PMID: 34707704 PMCID: PMC8543179 DOI: 10.3892/etm.2021.10857] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/07/2021] [Indexed: 12/31/2022] Open
Abstract
It has previously been reported that lung cancer has the highest morbidity and mortality rate worldwide; however, the pathogenesis underlying lung cancer has not been fully elucidated. The aim of the present was primarily to assess the influence of microRNA (miR)-106a-5p on the biological behaviors of lung cancer cells. In the present study, bioinformatics analysis was used to analyze the expression characteristics of miR-106a-5p and its relationship with the prognosis of patients with lung adenocarcinoma (LUAD) in The Cancer Genome Atlas. A dual luciferase reporter assay was performed to verify the binding of miR-106a-5p and liver kinase B1 (LKB1). The Cell Counting Kit-8, colony formation and Transwell assays were utilized to detect cell viability, proliferation and migration, respectively. Protein and RNA expression levels were examined by western blotting and reverse transcription-quantitative PCR analysis, respectively. It was observed that miR-106a-5p was highly expressed in LUAD and associated with poor prognosis. miR-106a-5p promoted the proliferation and migration of LUAD cells, and inhibited autophagy. By contrast, LKB1 inhibited cell proliferation and migration, promoted autophagy and blocked the cancer-promoting effects of miR-106a-5p. Overexpression of miR-106a-5p inhibited the phosphorylation of AMP-activated protein kinase (AMPK) and tuberin (TSC2), and promoted the phosphorylation of mTOR. By contrast, overexpression of LKB1 blocked the promotion of mTOR phosphorylation, and the inhibition of AMPK and TSC2 phosphorylation caused by miR-106a-5p. In summary, the results of the present study indicated that miR-106a-5p regulated the phosphorylation of the AMPK pathway by targeting LKB1, and was involved in the proliferation, migration and autophagy of LUAD cells.
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Affiliation(s)
- Yushan Zhou
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Yuxuan Zhang
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Yanli Li
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Liqiong Liu
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Zhidong Li
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Yanhong Liu
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
| | - Yi Xiao
- Department of Respiratory and Critical Care Medicine, Yan'an Hospital Affiliated to Kunming Medical University, Kunming, Yunnan 650051, P.R. China
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8
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Dai J, Chen Q, Huang W, Shi K, Zhang Y, Li T, Mou T, Huang Z, Wu Z. Liver kinase B1 attenuates liver ischemia/reperfusion injury via inhibiting the NLRP3 inflammasome. Acta Biochim Biophys Sin (Shanghai) 2021; 53:601-611. [PMID: 33783473 DOI: 10.1093/abbs/gmab030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Indexed: 02/05/2023] Open
Abstract
Liver ischemia/reperfusion injury (IRI), a serious inflammatory response driven by innate immunity, occurs in liver surgeries such as liver resection and liver transplantation, leading to liver dysfunction, liver failure, and even rejection after transplantation. Liver kinase B1 (LKB1) plays a pivotal anti-inflammatory role in IRI. One of the most important factors involved in liver IRI is the aberrant activation of the nucleotide binding oligomerization domain like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome in Kupffer cells. However, the mechanisms underlying the effect of LKB1 on the NLRP3 inflammasome in liver IRI remain elusive. In this study, we found that the expression of LKB1 was decreased in liver IRI, while the NLRP3 inflammasome level was increased as shown, as revealed by RT-qPCR and western blot analysis. Furthermore, upregulation of LKB1 abrogated the expression of the NLRP3 inflammasome, which improved liver function and liver pathology in the liver IRI model in vivo. In vitro, overexpression of LKB1 inhibited the activation of NLRP3 inflammasome and nuclear factor-κB, while the inhibitory effect was reversed by silencing the expression of the forkhead box protein O1 in the RAW264.7 macrophage hypoxia/reoxygenation model. In conclusion, our results suggest that LKB1 exerts a protective effect against liver IRI by downregulating the NLRP3 inflammasome.
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Affiliation(s)
- Jiangwen Dai
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Qingsong Chen
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Weifeng Huang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Kun Shi
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Yuke Zhang
- Department of Urology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tingting Li
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Tong Mou
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Zuotian Huang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
| | - Zhongjun Wu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400042, China
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9
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Lee EH, Baek SY, Park JY, Kim YW. Emodin in Rheum undulatum inhibits oxidative stress in the liver via AMPK with Hippo/Yap signalling pathway. Pharm Biol 2020; 58:333-341. [PMID: 32306810 PMCID: PMC7191907 DOI: 10.1080/13880209.2020.1750658] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 02/17/2020] [Accepted: 03/28/2020] [Indexed: 05/31/2023]
Abstract
Context: Emodin is a compound in Rheum undulatum Linne (Polygonaceae) that has been reported to exert anti-inflammatory, antibacterial, and antiallergic effects.Objective: Oxidative stress is a causative agent of liver inflammation that may lead to fibrosis and hepato-carcinoma. In this study, we investigated the antioxidant effects of emodin and its mechanism.Materials and methods: We used the hepatocyte stimulated by arachidonic acid (AA) + iron cotreatment and the C57B/6 mice orally injected with acetaminophen (APAP, 500 mg/kg, 6 h), as assessed by immunoblot and next generation sequencing (NGS). Emodin was pre-treated in hepatocyte (3 ∼ 30 μM) for 1 h before AA + iron, and in mice (10 and 30 m/kg, P.O.) for 3 days before APAP.Results: In vitro, emodin treatment inhibited the cell death induced by AA + iron maximally at a dose of 10 μM (EC50 > 3 μM). In addition, emodin attenuated the decrease of anti-apoptotic proteins, and restored mitochondria membrane potential as mediated by the liver kinase B1 (LKB1)-AMP-activated protein kinase (AMPK) pathway. LKB1 mediated AMPK activation was verified using the LKB1 deficient cell line, HeLa. Emodin (10 μM; after 10 min) also induced the phosphorylation of Yes-associated protein 1 (YAP1), the main downstream target of the Hippo signalling pathway that mediated oxidative stress or the ROS-initiated signalling pathway. In vivo, the oral treatment of emodin (10 and 30 m/kg, 3 days) decreased APAP-induced hepatic damage, as indicated by decreases in antioxidant genes as well as tissue damage.Conclusion: Our results show that emodin inhibits oxidative liver injury via the AMPK/YAP mediated pathway.
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Affiliation(s)
- Eun Hye Lee
- Department of Biomedical Science, Kyungpook National University, Daegu, Korea
| | - Su Youn Baek
- Institute for Phylogenomics and Evolution, Kyungpook National University, Daegu, Korea
| | - Ji Young Park
- Department of Biomedical Science, Kyungpook National University, Daegu, Korea
| | - Young Woo Kim
- School of Korean Medicine, Dongguk University, Gyeongju, Korea
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10
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Colombo M, Marabese M, Vargiu G, Broggini M, Caiola E. Activity of Birinapant, a SMAC Mimetic Compound, Alone or in Combination in NSCLCs With Different Mutations. Front Oncol 2020; 10:532292. [PMID: 33194590 PMCID: PMC7643013 DOI: 10.3389/fonc.2020.532292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 09/30/2020] [Indexed: 01/30/2023] Open
Abstract
Liver kinase B1 (LKB1/STK11) is the second tumor suppressor gene most frequently mutated in non-small-cell lung cancer (NSCLC) and its activity is impaired in about half KRAS-mutated NSCLCs. Nowadays, no effective therapies are available for patients having these mutations. To highlight new vulnerabilities of this subgroup of tumors exploitable to design specific therapies we screened an US FDA-approved drug library using an isogenic system of wild-type (WT) or deleted LKB1. Among eight hit compounds, Birinapant, an inhibitor of the Inhibitor of Apoptosis Proteins (IAPs), was the most active compound in LKB1-deleted clone only compared to its LKB1 WT counterpart. We validated the Birinapant cells response and its mechanism of action to be dependent on LKB1 deletion. Indeed, we demonstrated the ability of this compound to induce apoptosis, through activation of caspases in the LKB1-deleted clone only. Expanding our results, we found that the presence of KRAS mutations could mediate Birinapant resistance in a panel of NSCLC cell lines. The combination of Birinapant with Ralimetinib, inhibitor of p38α, restores the sensitivity of LKB1- and KRAS-mutated cell lines to the IAP inhibitor Birinapant. Our study shows how the use of Birinapant could be a viable therapeutic option for patients with LKB1-mutated NSCLCs. In addition, combination of Birinapant and a KRAS pathway inhibitor, as Ralimetinib, could be useful for patients with LKB1 and KRAS-mutated NSCLC.
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Affiliation(s)
- Marika Colombo
- Laboratory of Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Mirko Marabese
- Laboratory of Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Giulia Vargiu
- Laboratory of Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Massimo Broggini
- Laboratory of Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Elisa Caiola
- Laboratory of Molecular Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
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11
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Rana U, Callan E, Entringer B, Michalkiewicz T, Joshi A, Parchur AK, Teng RJ, Konduri GG. AMP-Kinase Dysfunction Alters Notch Ligands to Impair Angiogenesis in Neonatal Pulmonary Hypertension. Am J Respir Cell Mol Biol 2020; 62:719-731. [PMID: 32048878 DOI: 10.1165/rcmb.2019-0275oc] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Decreased angiogenesis contributes to persistent pulmonary hypertension of the newborn (PPHN); mechanisms remain unclear. AMPK (5'AMP activated protein kinase) is a key regulator of cell metabolism. We investigated the hypothesis that a decrease in AMPK function leads to mitochondrial dysfunction and altered balance of notch ligands delta-like 4 (DLL4) and Jagged 1 (Jag1) to impair angiogenesis in PPHN. Studies were done in fetal lambs with PPHN induced by prenatal ductus arteriosus constriction and gestation-matched control lambs. PPHN lambs were treated with saline or AMPK agonist metformin. Angiogenesis was assessed in lungs with micro-computed tomography angiography and histology. AMPK function; expression of mitochondrial electron transport chain (ETC) complex proteins I-V, Dll4, and Jag1; mitochondrial number; and in vitro angiogenesis function were assessed in pulmonary artery endothelial cells (PAEC) from control and PPHN lambs. AMPK function was decreased in PPHN PAEC and lung sections. Expression of mitochondrial transcription factor, PGC-1α, ETC complex proteins I-V, and mitochondrial number were decreased in PPHN. In vitro angiogenesis of PAEC and capillary number and vessel volume fraction in the lung were decreased in PPHN. Expression of DLL4 was increased and Jag1 was decreased in PAEC from PPHN lambs. AMPK agonists A769662 and metformin increased the mitochondrial complex proteins and number, in vitro angiogenesis, and Jag1 levels and decreased DLL4 levels in PPHN PAEC. Infusion of metformin in vivo increased the vessel density in PPHN lungs. Decreased AMPK function contributes to impaired angiogenesis in PPHN by altered balance of notch ligands in PPHN.
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Affiliation(s)
- Ujala Rana
- Department of Pediatrics and Children's Research Institute, and
| | - Emily Callan
- Department of Pediatrics and Children's Research Institute, and
| | | | | | - Amit Joshi
- Department of Radiology and Center for Imaging, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Abdul K Parchur
- Department of Radiology and Center for Imaging, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ru-Jeng Teng
- Department of Pediatrics and Children's Research Institute, and
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12
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Yang JH, Wu MZ, Wang XB, Wang S, Qiu XS, Wang EH, Wu GP. HPV16 E6/E7 upregulate hTERC mRNA and gene amplification levels by relieving the effect of LKB1 on Sp1 phosphorylation in lung cancer cells. Ther Adv Med Oncol 2020; 12:1758835920917562. [PMID: 32499837 PMCID: PMC7243384 DOI: 10.1177/1758835920917562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 03/04/2020] [Indexed: 11/18/2022] Open
Abstract
Background: There is an immediate need for research on the mechanism underlying
telomerase activation and overexpression. Materials & Methods: A total of 174 patients with lung cancer (n = 106) and
benign lung disease (n = 68) were recruited for the current
study. The mRNA expression levels of E6, E7, LKB1, Sp1, and hTERC in
brushing cells were detected by quantitative reverse transcriptase
polymerase chain reaction (qRT-PCR), and hTERC amplification was also
detected by fluorescence in situ hybridization (FISH). To investigate the
potential mechanism, bidirectional genetic manipulation was performed in
well-established lung cancer cell lines. Results: Our results indicated that the mRNA expression levels of E6, E7, Sp1, and
hTERC and the amplification level of hTERC were significantly increased in
the malignant group compared with those of the benign group
(p < 0.01). Conversely, the mRNA expression level of
LKB1 was significantly decreased in the malignant group
(p < 0.01). The correlation between E6, E7, Sp1, and
hTERC expression was positive but was negative with LKB1
(p < 0.01). Our results also showed that HPV16 E6/E7
downregulated the expression of LKB1 at both the protein and mRNA levels.
The loss of LKB1 upregulated Sp1 expression, and also promoted Sp1 activity.
Sp1 further upregulated hTERC at the mRNA and gene amplification levels.
Thus, we proposed a HPV–LKB1–Sp1–hTERC axis of E6/E7 upregulation of hTERC
expression. Conclusion: We demonstrated for the first time that E6 and E7 promoted hTERC mRNA
expression and the amplification of hTERC by relieving the effect of LKB1 on
the phosphorylation of Sp1. Sp1 further activated hTERC by directly binding
to the promoter regions of hTERC.
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Affiliation(s)
- Jing-Hua Yang
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Ming-Zhe Wu
- Department of Gynecology, The First Hospital of China Medical University, Shenyang, China
| | - Xu-Bo Wang
- Department of Pathology, Xuzhou City Hospital of TCM, Nanjing University of Chinese Medicine, Xuzhou, China
| | - Shiyu Wang
- Geisinger Commonwealth School of Medicine, Scranton, PA, USA
| | - Xue-Shan Qiu
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - En-Hua Wang
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Guang-Ping Wu
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, No.155 Nanjing Bei Street, Shenyang 110001, China
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13
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Zhou S, Fu Y, Zhang XB, Pei M. Liver Kinase B1 Fine-Tunes Lineage Commitment of Human Fetal Synovium-Derived Stem Cells. J Orthop Res 2020; 38:258-268. [PMID: 31429977 PMCID: PMC7294510 DOI: 10.1002/jor.24449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 07/25/2019] [Indexed: 02/04/2023]
Abstract
Liver kinase B1 (LKB1), a serine/threonine protein, is a key regulator in stem cell function and energy metabolism. Herein, we describe the role of LKB1 in modulating the differentiation of synovium-derived stem cells (SDSCs) toward chondrogenic, adipogenic, and osteogenic lineages. Human fetal SDSCs were transduced with CRISPR associated protein 9 (Cas9)-single-guide RNA vectors to knockout or lentiviral vectors to overexpress the LKB1 gene. Analyses including ICE (Inference of CRISPR Edits) data from Sanger sequencing and quantitative polymerase chain reaction (qPCR) as well as Western blot demonstrated successful knockout (KO) or overexpression (OE) of LKB1 in human fetal SDSCs without any detectable side effects in morphology, proliferation rate, and cell cycle. LKB1 KO increased CD146 expression; interestingly, LKB1 OE increased SSEA4 level. The qPCR data showed that LKB1 KO upregulated the levels of SOX2 and NANOG while LKB1 OE lowered the expression of POU5F1 and KLF4. Furthermore, LKB1 KO enhanced, and LKB1 OE inhibited, chondrogenic and adipogenic differentiation potential. However, perhaps due to the inherent inability to achieve osteogenesis, LKB1 did not obviously affect osteogenic differentiation. These data demonstrate that LKB1 plays a significant role in determining human SDSCs' adipogenic and chondrogenic differentiation, which might provide an approach for fine-tuning the direction of stem cell differentiation in tissue engineering and regeneration. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:258-268, 2020.
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Affiliation(s)
- Sheng Zhou
- Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, WV, 26506, USA,Department of Sports Medicine and Adult Reconstructive Surgery, Drum Tower Hospital, School of Medicine, Nanjing University, 321 Zhongshan Road, Nanjing, 210008, Jiangsu, China
| | - Yawen Fu
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Disease Hospital, Tianjin, China,Department of Medicine, Loma Linda University, Loma Linda, CA, USA
| | - Xiao-Bing Zhang
- State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Disease Hospital, Tianjin, China,Department of Medicine, Loma Linda University, Loma Linda, CA, USA,Co-corresponding author: Xiao-Bing Zhang, PhD. Division of Regenerative Medicine MC1528B, Department of Medicine, Loma Linda University, 11234 Anderson Street, Loma Linda, CA 92350, USA. Phone: 909-651-5886. Fax: 909-558-0428.
| | - Ming Pei
- Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, Morgantown, WV, 26506, USA,WVU Cancer Institute, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA,Corresponding author: Ming Pei MD, PhD, Stem Cell and Tissue Engineering Laboratory, Department of Orthopaedics, West Virginia University, PO Box 9196, 64 Medical Center Drive, Morgantown, WV 26506-9196, USA, Telephone: 304-293-1072; Fax: 304-293-7070;
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14
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Huang SW, Chyuan IT, Shiue C, Yu MC, Hsu YF, Hsu MJ. Lovastatin-mediated MCF-7 cancer cell death involves LKB1-AMPK-p38MAPK-p53-survivin signalling cascade. J Cell Mol Med 2019; 24:1822-1836. [PMID: 31821701 PMCID: PMC6991643 DOI: 10.1111/jcmm.14879] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 10/28/2019] [Accepted: 11/19/2019] [Indexed: 12/26/2022] Open
Abstract
There is increasing evidence that statins, which are widely used in lowering serum cholesterol and the incidence of cardiovascular diseases, also exhibits anti‐tumour properties. The underlying mechanisms by which statins‐induced cancer cell death, however, remain incompletely understood. In this study, we explored the anti‐tumour mechanisms of a lipophilic statin, lovastatin, in MCF‐7 breast cancer cells. Lovastatin inhibited cell proliferation and induced cell apoptosis. Lovastatin caused p21 elevation while reduced cyclin D1 and survivin levels. Lovastatin also increased p53 phosphorylation, acetylation and its reporter activities. Results from chromatin immunoprecipitation analysis showed that p53 binding to the survivin promoter region was increased, while Sp1 binding to the region was decreased, in MCF‐7 cells after lovastatin exposure. These actions were associated with liver kinase B1 (LKB1), AMP‐activated protein kinase (AMPK) and p38 mitogen‐activated protein kinase (p38MAPK) activation. Lovastatin's enhancing effects on p53 activation, p21 elevation and survivin reduction were significantly reduced in the presence of p38MAPK signalling inhibitor. Furthermore, LKB1‐AMPK signalling blockade abrogated lovastatin‐induced p38MAPK and p53 phosphorylation. Together these results suggest that lovastatin may activate LKB1‐AMPK‐p38MAPK‐p53‐survivin cascade to cause MCF‐7 cell death. The present study establishes, at least in part, the signalling cascade by which lovastatin induces breast cancer cell death.
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Affiliation(s)
- Shiu-Wen Huang
- Department of Medical Research, Taipei Medical University Hospital, Taipei, Taiwan.,Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - I-Tsu Chyuan
- Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan.,Department of Medical Research, Cathay General Hospital, Taipei, Taiwan.,School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei, Taiwan
| | - Ching Shiue
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Meng-Chieh Yu
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ya-Fen Hsu
- Division of General Surgery, Department of Surgery, Landseed Hospital, Taoyuan, Taiwan
| | - Ming-Jen Hsu
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
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15
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Kalinin S, Meares GP, Lin SX, Pietruczyk EA, Saher G, Spieth L, Nave KA, Boullerne AI, Lutz SE, Benveniste EN, Feinstein DL. Liver kinase B1 depletion from astrocytes worsens disease in a mouse model of multiple sclerosis. Glia 2019; 68:600-616. [PMID: 31664743 PMCID: PMC7337013 DOI: 10.1002/glia.23742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/19/2019] [Accepted: 10/05/2019] [Indexed: 12/15/2022]
Abstract
Liver kinase B1 (LKB1) is a ubiquitously expressed kinase involved in the regulation of cell metabolism, growth, and inflammatory activation. We previously reported that a single nucleotide polymorphism in the gene encoding LKB1 is a risk factor for multiple sclerosis (MS). Since astrocyte activation and metabolic function have important roles in regulating neuroinflammation and neuropathology, we examined the serine/threonine kinase LKB1 in astrocytes in a chronic experimental autoimmune encephalomyelitis mouse model of MS. To reduce LKB1, a heterozygous astrocyte-selective conditional knockout (het-cKO) model was used. While disease incidence was similar, disease severity was worsened in het-cKO mice. RNAseq analysis identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched in het-cKO mice relating to mitochondrial function, confirmed by alterations in mitochondrial complex proteins and reductions in mRNAs related to astrocyte metabolism. Enriched pathways included major histocompatibility class II genes, confirmed by increases in MHCII protein in spinal cord and cerebellum of het-cKO mice. We observed increased numbers of CD4+ Th17 cells and increased neuronal damage in spinal cords of het-cKO mice, associated with reduced expression of choline acetyltransferase, accumulation of immunoglobulin-γ, and reduced expression of factors involved in motor neuron survival. In vitro, LKB1-deficient astrocytes showed reduced metabolic function and increased inflammatory activation. These data suggest that metabolic dysfunction in astrocytes, in this case due to LKB1 deficiency, can exacerbate demyelinating disease by loss of metabolic support and increase in the inflammatory environment.
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Affiliation(s)
- Sergey Kalinin
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Gordon P Meares
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, West Virginia
| | - Shao Xia Lin
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | | | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Anne I Boullerne
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Sarah E Lutz
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, Illinois
| | - Etty N Benveniste
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Douglas L Feinstein
- Department of Anesthesiology, University of Illinois, Chicago, Illinois.,Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, Illinois
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16
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Ren YH, Zhao FJ, Mo HY, Jia RR, Tang J, Zhao XH, Wei JL, Huo RR, Li QQ, You XM. Association between LKB1 expression and prognosis of patients with solid tumours: an updated systematic review and meta-analysis. BMJ Open 2019; 9:e027185. [PMID: 31383697 PMCID: PMC6687027 DOI: 10.1136/bmjopen-2018-027185] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Liver kinase B1 (LKB1) is considered a tumour suppressor that can control cell growth and metabolism. Whether LKB1 expression levels are related to clinicopathology and prognosis is controversial. This review aimed to quantitatively examine the latest evidence on this question. DESIGN An updated systematic review and meta-analysis on the association between LKB1 expression and prognosis of patients with solid tumours were performed. DATA SOURCES Eligible studies were identified through literature searches from database establishment until 15 June 2018 in the following databases: Embase, PubMed, Web of Science, Cochrane Library, China National Knowledge Infrastructure and Wan Fang databases. ELIGIBILITY CRITERIA The association between LKB1 expression and clinicopathological characteristics, overall survival (OS), disease-free survival (DFS) and relapse-free survival (RFS) of patients with solid tumours were reported. Sufficient data were available to calculate the OR or HR and 95% CI. DATA EXTRACTION AND SYNTHESIS Relevant data were meta-analysed for OS, DFS, RFS and various clinical parameters. RESULTS The systematic review included 25 studies containing 6012 patients with solid tumours. Compared with patients with high LKB1 expression, patients with low expression showed significantly shorter OS in univariate analysis (HR=1.63, 95% CI 1.35 to 1.97, p<0.01) and multivariate analysis (HR=1.61, 95% CI 1.26 to 2.06, p<0.01). In contrast, the two groups showed similar DFS in univariate analysis (HR=1.49, 95% CI 0.73 to 3.01, p=0.27) as well as similar RFS in univariate analysis (HR=1.44, 95% CI 0.65 to 3.17, p=0.37) and multivariate analysis (HR=1.02, 95% CI 0.42 to 2.47, p=0.97). Patients with low LKB1 expression showed significantly worse tumour differentiation (OR=1.71, 95% CI 1.14 to 2.55, p<0.01), larger tumours (OR=1.68, 95% CI 1.24 to 2.27, p<0.01), earlier lymph node metastasis (OR=1.43, 95% CI 1.26 to 1.62, p<0.01) and more advanced tumour, node, metastases (TNM) stage (OR=1.80, 95% CI 1.56 to 2.07, p<0.01). CONCLUSION Low LKB1 expression predicts shorter OS, worse tumour differentiation, larger tumours, earlier lymph node metastasis and more advanced TNM stage. Low LKB1 expression may be a useful biomarker of poor clinicopathology and prognosis.
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Affiliation(s)
- Yun Hong Ren
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Feng Juan Zhao
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Han Yue Mo
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Rong Rong Jia
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Juan Tang
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xin Hua Zhao
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jue Ling Wei
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Rong Rui Huo
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Qiu Qin Li
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xue Mei You
- Hepatobiliary Surgery Department, Affiliated Tumor Hospital of Guangxi Medical University, Nanning, Guangxi, China
- Guangxi Liver Cancer Diagnosis and Treatment Engineering and Technology Research Center, Nanning, Guangxi, China
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17
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He L, Wu MZ, Wang XB, Qiu XS, Wang EH, Wu GP. Tumor Suppressor LKB1 inhibits both the mRNA Expression and the Amplification of hTERC by the Phosphorylation of YAP in Lung Cancer Cells. J Cancer 2019; 10:3632-3638. [PMID: 31333780 PMCID: PMC6636284 DOI: 10.7150/jca.33237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/03/2019] [Indexed: 12/18/2022] Open
Abstract
Liver kinase B1 (LKB1) is a critical tumor suppressor that is frequently mutated in human cancers. LKB1 has serine/threonine protein kinase activity, which regulates gene expression by phosphorylation of Yes-Associated protein (YAP). The phosphorylation-dependent YAP shuttling is critically important intracellular mechanism in the Hippo pathway. In our previous study, we found that the amplification of hTERC was significant higher in the bronchial brushing cells of patients with lung cancer, however, the underlying molecular mechanism is not clear. In this study, we showed that LKB1 overexpression could phosphorylate YAP and promoted its nuclear rejection. Silencing LKB1 could dephosphorylate YAP and promoted its entry into the nucleus. Here, we found that LKB1 inhibited the mRNA expression and the amplification of hTERC. YAP further up-regulated hTERC at mRNA and gene amplification levels. Therefore, we suggest that LKB1 may inhibit the expression and amplification of hTERC through the axis of LKB1-pYAP(YAP)-hTERC.
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Affiliation(s)
- Ling He
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang 110001, China
| | - Ming-Zhe Wu
- Department of Gynecology, The First Hospital of China Medical University, Shenyang 110001, China
| | - Xu-Bo Wang
- Department of Pathology, Xuzhou City Hospital of TCM, Nanjing University of Chinese Medicine, Xuzhou 221000, China
| | - Xue-Shan Qiu
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang 110001, China
| | - En-Hua Wang
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang 110001, China
| | - Guang-Ping Wu
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang 110001, China
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18
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Abstract
Background Liver kinase B1 (LKB1) is a newly discovered tumor suppressor gene that plays a role in apoptosis induction. However, the precise impact of LKB1 expression on gastric cancer (GC) progression and its correlation with survivin and p53 in GC have not yet been elucidated. Purpose The aim of this study was to explore the significance of LKB1 expression and its correlation with p53 and survivin in GC. Patients and methods In this study, LKB1 expression was detected in GC and adjacent paracancerous tissues from 150 patients through immunohistochemical (IHC) staining. The relationship between LKB1 expression and clinical pathological factors in GC was analyzed, alongside its correlation with p53 and survivin expression. Results LKB1 expression was reduced in GC tissues compared with adjacent paracancerous tissues (P=0.001). In patients with GC, lower LKB1 expression was associated with greater invasion depth (P=0.013), higher pTNM stage (P=0.009), and lymph node metastasis (P=0.029). Furthermore, LKB1 expression in GC was inversely associated with p53 (r=-0.181, P=0.027) and survivin expression (r=-0.198, P=0.015). Kaplan-Meier analysis indicated that the expression of LKB1, p53 and survivin, as well as tumor differentiation, invasion, and pTNM and lymph node metastasis were all associated with overall survival (OS) (all P<0.05). Finally, multivariate analysis showed that LKB1 expression [hazard ratio (HR): 0.605 (0.414-0.882), P=0.009], p53 expression [hazard ratio (HR): 1.840 (1.232-2.750), P=0.003], and survivin expression [hazard ratio (HR): 1.561 (1.039-2.345), P=0.032] were all independent prognostic factors for patients with GC. Conclusion Our study suggests that LKB1 expression is reduced in GC, negatively correlated with p53 and survivin expression, and plays an important role in predicting invasion and metastasis of GC.
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Affiliation(s)
- Weiwei Li
- Department of Oncology, The First People's Hospital of Tianmen City, Hubei, China
| | - Shunxiang Luo
- Department of Oncology, The First People's Hospital of Tianmen City, Hubei, China
| | - Guowei Ma
- Department of Gastrointestinal Surgery, The First People's Hospital of Tianmen City, Hubei, China
| | - Lin Wang
- Department of Pathology, The First People's Hospital of Tianmen City, Hubei, China,
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Zhang M, Li H, Zhang Y, Li H. Oncogenic miR-744 promotes prostate cancer growth through direct targeting of LKB1. Oncol Lett 2018; 17:2257-2265. [PMID: 30675291 PMCID: PMC6341651 DOI: 10.3892/ol.2018.9822] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 10/25/2018] [Indexed: 12/12/2022] Open
Abstract
Prostate cancer (PCa) is one of the most common malignancies worldwide, and with a limited number of treatments for this type of cancer, its incidence is rapidly increasing. Patients presenting with PCa are likely to experience disease recurrence, which represents a considerable clinical challenge. MicroRNAs (miRNAs) have been widely characterized as a critical regulator in a number of types of cancer, including PCa. miRNA-744 (miR-744) has been reported to be involved in cancer regulation; however, its role in PCa remained poorly understood. In a recent study, it was demonstrated that miR-744 was overexpressed in prostate tissue from PCa patients when compared with the surrounding tissues, and knockdown of miR-744 resulted in reduced cell growth. In addition, an increased population of apoptotic cells was detected upon miR-744 knockdown, together with a decrease in cell proliferation. Cell cycle analysis demonstrated a higher number of cells in the G1 phase and lower numbers in the S phase following miR-744 silencing. The levels of key proteins involved in cell cycle progression (cyclin D1, cyclin-dependent kinase 4, and proliferating cell nuclear antigen) were increased, whereas those proteins responsible for cell cycle inhibition (cyclin-dependent kinase inhibitor p21) were decreased. The tumor suppressor liver kinase B1 (LKB1) was revealed to be a potential target of miR-744, suggesting its potential mechanism of action. LKB1 levels were negatively correlated with miR-744, and LKB1 was indicated to be a direct target of miR-744. Furthermore, it was revealed that by targeting LKB1, miR-744 may regulate adenosine monophosphate-activated protein kinase (AMPK); the AMPK signaling pathway was activated by miR-744 knockdown, with subsequent inhibition of the mammalian target of rapamycin (mTOR) signaling pathway. Taken together, these results demonstrated that miR-744 promoted cell growth through the AMPK signaling pathway, by targeting LKB1. The present study revealed a novel insight into the biological function of miR-744 in PCa, and that miR-744 may be a potential therapeutic target.
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Affiliation(s)
- Minglei Zhang
- Department of Orthopedics, China and Japan Union Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Hai Li
- Department of Urology, China and Japan Union Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Yun Zhang
- Department of Urology, China and Japan Union Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
| | - Hongyan Li
- Department of Urology, China and Japan Union Hospital of Jilin University, Changchun, Jilin 130000, P.R. China
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20
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Qiu B, Wei W, Zhu J, Fu G, Lu D. EMT induced by loss of LKB1 promotes migration and invasion of liver cancer cells through ZEB1-induced YAP signaling. Oncol Lett 2018; 16:6465-6471. [PMID: 30405784 PMCID: PMC6202531 DOI: 10.3892/ol.2018.9445] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/07/2018] [Indexed: 12/27/2022] Open
Abstract
Liver cancer cells often exhibit mesenchymal phenotypes, a critical phenotypic alteration of cancer cells termed the epithelial-mesenchymal transition (EMT). To examine whether liver kinase B1 (LKB1) serves a potential role in EMT in liver carcinogenesis, in the present study, it was determined that the expression of LKB1 decreased in the hepatocellular carcinoma (HCC) cell line, compared with a normal liver cell line. LKB1 overexpression decreased cell motility and invasiveness. Furthermore, the loss of LKB1 induced the expression of several EMT marker proteins, including that of Zinc Finger E-Box Binding Homeobox 1 (ZEB1). Notably, the expression of Yes-associated protein (YAP) was positively associated with that of ZEB1 in LKB1-knockdown cells with a mesenchymal phenotype. Here, we describe the direct regulation of the Hippo pathway effector YAP by ZEB1. The findings of the present study demonstrate that ZEB1 regulates the expression of YAP and regulates the expression of downstream target genes to promote malignant progression.
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Affiliation(s)
- Bijun Qiu
- General Surgery Department, Jiangdu People's Hospital Affiliated to Yangzhou University, Yangzhou, Jiangsu 321088, P.R. China
| | - Wei Wei
- General Surgery Department, Jiangdu People's Hospital Affiliated to Yangzhou University, Yangzhou, Jiangsu 321088, P.R. China
| | - Jianwen Zhu
- Pathology Department, Hong Quan Hospital of Yangzhou, Yangzhou, Jiangsu 321088, P.R. China
| | - Guangshun Fu
- General Surgery Department, Jiangdu People's Hospital Affiliated to Yangzhou University, Yangzhou, Jiangsu 321088, P.R. China
| | - Dahai Lu
- General Surgery Department, Jiangdu People's Hospital Affiliated to Yangzhou University, Yangzhou, Jiangsu 321088, P.R. China
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21
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Ji J, Xue TF, Guo XD, Yang J, Guo RB, Wang J, Huang JY, Zhao XJ, Sun XL. Antagonizing peroxisome proliferator-activated receptor γ facilitates M1-to-M2 shift of microglia by enhancing autophagy via the LKB1-AMPK signaling pathway. Aging Cell 2018; 17:e12774. [PMID: 29740932 PMCID: PMC6052482 DOI: 10.1111/acel.12774] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/16/2018] [Indexed: 12/25/2022] Open
Abstract
Microglia‐mediated neuroinflammation plays a dual role in various brain diseases due to distinct microglial phenotypes, including deleterious M1 and neuroprotective M2. There is growing evidence that the peroxisome proliferator‐activated receptor γ (PPARγ) agonist rosiglitazone prevents lipopolysaccharide (LPS)‐induced microglial activation. Here, we observed that antagonizing PPARγ promoted LPS‐stimulated changes in polarization from the M1 to the M2 phenotype in primary microglia. PPARγ antagonist T0070907 increased the expression of M2 markers, including CD206, IL‐4, IGF‐1, TGF‐β1, TGF‐β2, TGF‐β3, G‐CSF, and GM‐CSF, and reduced the expression of M1 markers, such as CD86, Cox‐2, iNOS, IL‐1β, IL‐6, TNF‐α, IFN‐γ, and CCL2, thereby inhibiting NFκB–IKKβ activation. Moreover, antagonizing PPARγ promoted microglial autophagy, as indicated by the downregulation of P62 and the upregulation of Beclin1, Atg5, and LC3‐II/LC3‐I, thereby enhancing the formation of autophagosomes and their degradation by lysosomes in microglia. Furthermore, we found that an increase in LKB1–STRAD–MO25 complex formation enhances autophagy. The LKB1 inhibitor radicicol or knocking down LKB1 prevented autophagy improvement and the M1‐to‐M2 phenotype shift by T0070907. Simultaneously, we found that knocking down PPARγ in BV2 microglial cells also activated LKB1–AMPK signaling and inhibited NFκB–IKKβ activation, which are similar to the effects of antagonizing PPARγ. Taken together, our findings demonstrate that antagonizing PPARγ promotes the M1‐to‐M2 phenotypic shift in LPS‐induced microglia, which might be due to improved autophagy via the activation of the LKB1–AMPK signaling pathway.
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Affiliation(s)
- Juan Ji
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Teng-Fei Xue
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Xu-Dong Guo
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Jin Yang
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Ruo-Bing Guo
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Juan Wang
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Ji-Ye Huang
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Xiao-Jie Zhao
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
| | - Xiu-Lan Sun
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Nanjing Jiangsu China
- Jiangsu Key Laboratory of Neurodegeneration; Department of Pharmacology; Nanjing Medical University; Nanjing Jiangsu China
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22
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Konagaya Y, Terai K, Hirao Y, Takakura K, Imajo M, Kamioka Y, Sasaoka N, Kakizuka A, Sumiyama K, Asano T, Matsuda M. A Highly Sensitive FRET Biosensor for AMPK Exhibits Heterogeneous AMPK Responses among Cells and Organs. Cell Rep 2017; 21:2628-38. [PMID: 29186696 DOI: 10.1016/j.celrep.2017.10.113] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/28/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK), a master regulator of cellular metabolism, is a potential target for type 2 diabetes. Although extensive in vitro studies have revealed the complex regulation of AMPK, much remains unknown about the regulation in vivo. We therefore developed transgenic mice expressing a highly sensitive fluorescence resonance energy transfer (FRET)-based biosensor for AMPK, called AMPKAR-EV. AMPKAR-EV allowed us to readily examine the role of LKB1, a canonical stimulator of AMPK, in drug-induced activation and inactivation of AMPK in vitro. In transgenic mice expressing AMPKAR-EV, the AMP analog AICAR activated AMPK in muscle. In contrast, the antidiabetic drug metformin activated AMPK in liver, highlighting the organ-specific action of AMPK stimulators. Moreover, we found that AMPK was activated primarily in fast-twitch muscle fibers after tetanic contraction and exercise. These observations suggest that the AMPKAR-EV mouse will pave a way to understanding the heterogeneous responses of AMPK among cell types in vivo.
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23
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Song L, Guo J, Chang R, Peng X, Li J, Xu X, Zhan X, Zhan L. LKB1 obliterates Snail stability and inhibits pancreatic cancer metastasis in response to metformin treatment. Cancer Sci 2018; 109:1382-1392. [PMID: 29601127 PMCID: PMC5980291 DOI: 10.1111/cas.13591] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 03/11/2018] [Accepted: 03/15/2018] [Indexed: 02/06/2023] Open
Abstract
Metastasis to distant organs is a particularly ominous feature of malignant cancer. LKB1 (also known as STK11) has been identified as a tumor suppressor in several types of cancers. Here, we show that LKB1 is at low levels and is negatively associated with poor clinical outcomes in pancreatic cancer (PC). LKB1 is inversely correlated with Snail protein in PC, in which the loss of LKB1 facilitates metastasis through elevating Snail protein level. Furthermore, LKB1 boosts Snail's interaction with E3 ligase FBXL14, leading to increasing ubiquitin‐mediated Snail degradation. Notably, metformin could increase Snail protein ubiquitination via augmenting the location of LKB1 at cytoplasm as well as increasing LKB1 expression. Altogether, our data established that LKB1 impedes invasion and metastasis by decreasing the Snail protein level in PC. Targeting the LKB1/FBXL14/Snail axis may represent a promising therapeutic strategy and metformin might be beneficial for PC therapy through activating the LKB1‐mediated Snail ubiquitination pathway.
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Affiliation(s)
- Lele Song
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Shanghai, China.,Changhai Hospital, The Second Military Medical University, Shanghai, China
| | - Jingyu Guo
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Shanghai, China
| | - Renxu Chang
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.,University of the Chinese Academy of Sciences, Shanghai, China
| | - Xiaobo Peng
- Changhai Hospital, The Second Military Medical University, Shanghai, China
| | - Jie Li
- Changhai Hospital, The Second Military Medical University, Shanghai, China
| | - Xiaorong Xu
- Department of Gastroenterology, The Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Xianbao Zhan
- Changhai Hospital, The Second Military Medical University, Shanghai, China
| | - Lixing Zhan
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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24
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Zulato E, Ciccarese F, Nardo G, Pinazza M, Agnusdei V, Silic-Benussi M, Ciminale V, Indraccolo S. Involvement of NADPH Oxidase 1 in Liver Kinase B1-Mediated Effects on Tumor Angiogenesis and Growth. Front Oncol 2018; 8:195. [PMID: 29915721 PMCID: PMC5994402 DOI: 10.3389/fonc.2018.00195] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/14/2018] [Indexed: 12/25/2022] Open
Abstract
The liver kinase B1 (LKB1) gene is a tumor suppressor with an established role in the control of cell metabolism and oxidative stress. However, whether dis-regulated oxidative stress promotes growth of LKB1-deficient tumors remains substantially unknown. Through in vitro studies, we observed that loss of LKB1 perturbed expression of several genes involved in reactive oxygen species (ROS) homeostasis. In particular, this analysis evidenced strongly up-modulated NADPH oxidase 1 (NOX1) transcript levels in tumor cells lacking LKB1. NOX1 accounted in part for enhanced cytotoxic effects of H2O2-induced oxidative stress in A549 LKB1-deficient tumor cells. Notably, genetic and pharmacologic inhibition of NOX1 activity reduced angiogenesis and growth of A549 tumors in mice. These results suggest that NOX1 inhibitors could counteract ROS production and the angiogenic switch in LKB1-deficient tumors.
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Affiliation(s)
| | - Francesco Ciccarese
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy
| | - Giorgia Nardo
- Istituto Oncologico Veneto IOV - IRCCS, Padova, Italy
| | | | | | | | - Vincenzo Ciminale
- Istituto Oncologico Veneto IOV - IRCCS, Padova, Italy.,Department of Surgery, Oncology and Gastroenterology, University of Padova, Padova, Italy
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25
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Song K, Zheng G, Zhao Y. Liver kinase B1 suppresses growth of lung cancer cells through sonic hedgehog signaling pathway. Cell Biol Int 2018; 42:994-1005. [PMID: 29573522 DOI: 10.1002/cbin.10965] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/19/2018] [Indexed: 01/10/2023]
Abstract
Lung cancer is one of life-threatening cancers in the worldwide. Liver kinase B1 (LKB1) has been reported to be closely related to cancers; however, the underlying mechanism of LKB1 in lung cancer remains unclear. In our study, a LKB1 specific shRNA was employed to down-regulate LKB1 levels and a LKB1 over-expression plasmid was constructed to up-regulate LKB1 levels. Thereafter, growth of lung cancer cells was assessed by MTT assay and flow cytometry. Effects of LKB1 on the activation of sonic hedgehog (Shh) signaling pathway were detected by Western blot. Effects of LKB1 on lung cancer growth and Shh signaling pathway activation were also assessed in vivo. Our results showed that LKB1 inhibited proliferation of lung cancer cells and induced their apoptosis. Moreover, LKB1 inhibited Shh signaling pathway activation. Our in vivo study also showed that LKB1 inhibited lung cancer growth in vivo and modulated Shh signaling pathway. Treatment with cyclopamine, a Shh signaling pathway inhibitor, reversed the effects of LKB1 silencing and enhanced the effects of LKB1 over-expression. Results of our study demonstrate that LKB1 inhibits lung cancer growth in vitro and in vivo through Shh signaling pathway.
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Affiliation(s)
- Kuiyuan Song
- Department of Pathology, College of Basic Medical Sciences, China Medical University, Shenyang 110122, People's Republic of China
| | - Guanqun Zheng
- Department of Pathology, College of Basic Medical Sciences, China Medical University, Shenyang 110122, People's Republic of China
| | - Yue Zhao
- Department of Pathology, College of Basic Medical Sciences and the First Affiliated Hospital, China Medical University, Shenyang 110122, People's Republic of China
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26
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Ma Q, Xiao P, Sun L, Wang J, Zhong D. Liver kinase B1/adenosine monophosphate-activated protein kinase signaling axis induces p21/WAF1 expression in a p53-dependent manner. Oncol Lett 2018; 16:1291-1297. [PMID: 29963200 DOI: 10.3892/ol.2018.8741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Accepted: 05/23/2017] [Indexed: 01/05/2023] Open
Abstract
Liver kinase B1 (LKB1) encodes a serine/threonine kinase and functions as a tumor suppressor. LKB1 loss-of-function somatic mutations are frequently observed in sporadic types of cancer, particularly in lung cancer. Ectopic LKB1 induces growth arrest by upregulating p21/cyclin dependent kinase inhibitor 1A (WAF1) in LKB1 deficient cervical and melanoma cancer cell lines. However, the underlying molecular mechanism remains to be elucidated. The present study built upon previous observations by confirming that the ectopic expression level of LKB1 significantly reduced colony formation of LKB1-deficient lung cancer cells. Mechanistically, the present study demonstrated that LKB1 overexpression significantly induced p21/WAF1 expression in a kinase-dependent manner. Conversely, LKB1 stable knockdown resulted in a decrease in p21/WAF1 expression level in colon cancer cells. In addition, it was revealed that pharmacological activation of adenosine monophosphate protein kinase (AMPK) by 2-deoxyglucose significantly increased the p21/WAF1 expression level, suggesting that AMPK acts downstream of LKB1 to induce p21/WAF1 expression. Furthermore, the present study demonstrated that functional p53 was required for p21/WAF1 induction by LKB1. Phosphorylation of p53-Ser15 was increased by ectopic LKB1 or AMPK activation. Taken together, these results suggested that LKB1 acts via its substrate, AMPK, to upregulate p21/WAF1 expression in a p53-dependent manner. Therefore, the present study identified an important signaling axis, providing novel molecular insights into the tumor suppressor role of LKB1.
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Affiliation(s)
- Qing Ma
- Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China
| | - Ping Xiao
- Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China
| | - Linlin Sun
- Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China
| | - Jing Wang
- Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China
| | - Diansheng Zhong
- Department of Medical Oncology, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China.,Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin, Hebei 300052, P.R. China
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27
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Xiong Y, Xu Z, Wang Y, Kuang S, Shan T. Adipocyte-specific DKO of Lkb1 and mTOR protects mice against HFD-induced obesity, but results in insulin resistance. J Lipid Res 2018; 59:974-981. [PMID: 29636366 DOI: 10.1194/jlr.m081463] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/01/2018] [Indexed: 12/14/2022] Open
Abstract
Liver kinase B1 (Lkb1) and mammalian target of rapamycin (mTOR) are key regulators of energy metabolism and cell growth. We have previously reported that adipocyte-specific KO of Lkb1 or mTOR in mice results in distinct developmental and metabolic phenotypes. Here, we aimed to assess how genetic KO of both Lkb1 and mTOR affects adipose tissue development and function in energy homeostasis. We used Adiponectin-Cre to drive adipocyte-specific double KO (DKO) of Lkb1 and mTOR in mice. We performed indirect calorimetry, glucose and insulin tolerance tests, and gene expression assays on the DKO and WT mice. We found that DKO of Lkb1 and mTOR results in reductions of brown adipose tissue and inguinal white adipose tissue mass, but in increases of liver mass. Notably, the DKO mice developed fatty liver and insulin resistance, but displayed improved glucose tolerance after high-fat diet (HFD)-feeding. Interestingly, the DKO mice were protected from HFD-induced obesity due to their higher energy expenditure and lower expression levels of adipogenic genes (CCAAT/enhancer binding protein α and PPARγ) compared with WT mice. These results together indicate that, compared with Lkb1 or mTOR single KOs, Lkb1/mTOR DKO in adipocytes results in overlapping and distinct metabolic phenotypes, and mTOR KO largely overrides the effect of Lkb1 KO.
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Affiliation(s)
- Yan Xiong
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907; College of Life Science and Technology, Southwest Minzu University, Chengdu, Sichuan 610041, China; Joint Laboratory of Lipid Metabolism, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Beijing 100193, China
| | - Ziye Xu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yizhen Wang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shihuan Kuang
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907; Joint Laboratory of Lipid Metabolism, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Beijing 100193, China.
| | - Tizhong Shan
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Department of Animal Sciences, Purdue University, West Lafayette, IN 47907.
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28
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Li D, Zhou Y, Liu Y, Lin Y, Yu M, Lu X, Huang B, Sun Z, Jian Z, Hou B. Decreased expression of LKB1 predicts poor prognosis in pancreatic neuroendocrine tumor patients undergoing curative resection. Onco Targets Ther 2018; 11:1259-1265. [PMID: 29563804 PMCID: PMC5846316 DOI: 10.2147/ott.s154168] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background Liver kinase B1 (LKB1) is a key regulatory protein of cellular metabolism, proliferation, and polarity. The present study aimed to characterize the expression pattern of LKB1 in pancreatic neuroendocrine tumors (pNETs) and evaluate the relationship between LKB1 expression and prognosis in pNETs. Patients and methods We retrospectively analyzed the pathologic and clinical data of 71 pNET patients who underwent curative surgical resection in Guangdong General Hospital. LKB1 mRNA and protein levels in tumor tissues and paired nontumor tissues were evaluated in 24 patients by quantitative real-time reverse-transcription polymerase chain reaction and Western blot, respectively. Immunohistochemical expression of LKB1 in tumor tissues was detected in all of the 71 patients, and the immunohistochemical expression level was re-coded in two classes (high versus low/negative) and correlated with clinicopathological parameters and survival outcomes. The association between LKB1 expression and clinicopathological characters was evaluated by chi-square test and Student’s t-test. Kaplan–Meier curves and log-rank test were used to analyze the survival outcomes, including overall survival (OS) and disease-free survival (DFS). Results Compared to adjacent normal tissues, LKB1 mRNA level and protein expression level in tumor tissues were both increased. The immunostaining of LKB1 was mainly found within the cytoplasm. Overall, 52 of 71 (73.2%) cases were positive for LKB1 protein, which showed either a diffuse staining pattern or a partial staining pattern. Decreased LKB1 expression was correlated with older age (P=0.042), increased Ki-67 index (P=0.004), increased mitotic count (P=0.001), and advanced histologic grade (P=0.001). Moreover, patients with low/negative LKB1 expression had shorter OS and DFS than those with high expression. Conclusion Our results suggested that LKB1 expression could be a useful prognostic marker for recurrence and survival in pNET patients who had received curative resection.
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Affiliation(s)
- Dezhi Li
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Yu Zhou
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Yanhui Liu
- Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Ye Lin
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Min Yu
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Xin Lu
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Bowen Huang
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Zhonghai Sun
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Zhixiang Jian
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Baohua Hou
- Department of General Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
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Shao JS, Sun J, Wang S, Chung K, Du JT, Wang J, Qiu XS, Wang EH, Wu GP. HPV16 E6/E7 upregulates HIF-2α and VEGF by inhibiting LKB1 in lung cancer cells. Tumour Biol 2017; 39:1010428317717137. [PMID: 28720067 DOI: 10.1177/1010428317717137] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Long-term persistent infection of HPV16 E6/E7 is frequently associated with lung cancers, especially in non-smokers and in Asians. However, molecular mechanisms of HPV16 E6/E7 induction of lung cancer are not fully understood. Using bi-directional genetic manipulation and four well-established lung cancer cell lines, we showed HPV16 E6/E7 downregulated expression of liver kinase B1 at both protein and messenger RNA levels; liver kinase B1 downregulated hypoxia-inducible factor 2α at protein level but not at messenger RNA level, and hypoxia-inducible factor 2α upregulated vascular endothelial growth factor at both protein and messenger RNA levels. This is the first study to show hypoxia-inducible factor 2α as a downstream effector of liver kinase B1 in lung cancer cells. Our results indicate that HPV16 E6/E7 indirectly upregulated the expression of vascular endothelial growth factor by inhibition of liver kinase B1 expression and upregulation of hypoxia-inducible factor 2α expression, thus propose a human papillomavirus-liver kinase B1-hypoxia-inducible factor 2α-vascular endothelial growth factor axis for the tumorigenesis of lung cancer. Our study also provides new evidence to support the critical role of liver kinase B1 in the pathogenesis of human papillomavirus-related lung cancer and suggests novel therapeutic targets.
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Affiliation(s)
- Jian-Shuang Shao
- 1 Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Jian Sun
- 1 Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Shiyu Wang
- 2 Geisinger Commonwealth School of Medicine, Scranton, PA, USA
| | - Katherine Chung
- 2 Geisinger Commonwealth School of Medicine, Scranton, PA, USA
| | - Jin Tong Du
- 3 Department of Physiology and Pharmacology, Schulich Medicine & Dentistry, Western University, London, ON, Canada
| | - Jason Wang
- 4 College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, MI, USA
| | - Xue-Shan Qiu
- 1 Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - En-Hua Wang
- 1 Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Guang-Ping Wu
- 1 Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
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30
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Zhang W, Li X, Song G, Luo D. Prognostic significance of LKB1 promoter methylation in cutaneous malignant melanoma. Oncol Lett 2017; 14:2075-2080. [PMID: 28781649 PMCID: PMC5530115 DOI: 10.3892/ol.2017.6431] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 04/13/2017] [Indexed: 11/07/2022] Open
Abstract
Liver kinase B1 (LKB1) loss is a common occurrence in various types of human cancer, and promoter methylation has been hypothesized to be a major mechanism of LKB1 inactivation. The association between LKB1 gene promoter methylation status and tumor progression in cutaneous malignant melanoma (CMM) remains unknown. In the present study, the methylation status of the LKB1 promoter region was examined in 57 human cutaneous malignant melanomas and 50 benign skin lesion controls by methylation-specific polymerase chain reaction. Consequently, 12 (12/57) melanoma tissues exhibited LKB1 promoter methylation, while only 2 (2/50) benign lesions presented with LKB1 hypermethylation. The frequency of LKB1 promoter methylation in melanoma was significantly increased compared with the benign controls (P<0.05). Additional statistical analysis demonstrated that hypermethylation of the LKB1 gene was correlated with Breslow's thickness, presence of ulceration and American Joint Committee on Cancer stage (P<0.05). Additionally, Kaplan-Meier analysis revealed that LKB1 hypermethylation was significantly associated with poorer survival (P<0.01). Multivariate COX regression analysis indicated that LKB1 promoter methylation was an independent prognostic factor for overall survival in patients with melanoma.
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Affiliation(s)
- Weiming Zhang
- Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Xiao Li
- Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Guoxin Song
- Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Dan Luo
- Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
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31
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Lu Y, Ding S, Zhou R, Wu J. Structure of the complex of phosphorylated liver kinase B1 and 14-3-3ζ. Acta Crystallogr F Struct Biol Commun 2017; 73:196-201. [PMID: 28368277 PMCID: PMC5379168 DOI: 10.1107/s2053230x17003521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 03/04/2017] [Indexed: 12/12/2022] Open
Abstract
The serine/threonine protein kinase liver kinase B1 (LKB1) is a tumour suppressor and plays important roles in development and metabolism. It phosphorylates AMPK and AMPK-related kinases to regulate multiple physiological processes. Mutations in LKB1 often occur in multiple cancers. LKB1 can be suppressed by 14-3-3 proteins in a phosphorylation-dependent manner. Previously, the structure of a 14-3-3ζ-LKB1 fusion protein has been reported, revealing a phosphorylation-independent binding mode of LKB1 to 14-3-3 proteins. Here, the crystal structure of phosphorylated LKB1 peptide in complex with 14-3-3ζ was solved, which provides a structural basis for the phosphorylation-dependent recognition of LKB1 by 14-3-3 proteins.
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Affiliation(s)
- Yongjian Lu
- Department of Stomatology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, People’s Republic of China
| | - Sheng Ding
- Department of Stomatology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, People’s Republic of China
| | - Ruiqing Zhou
- Department of Stomatology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, People’s Republic of China
| | - Jianyong Wu
- Department of Stomatology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200092, People’s Republic of China
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32
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George JW, Patterson AL, Tanwar PS, Kajdacsy-Balla A, Prins GS, Teixeira JM. Specific deletion of LKB1/ Stk11 in the Müllerian duct mesenchyme drives hyperplasia of the periurethral stroma and tumorigenesis in male mice. Proc Natl Acad Sci U S A 2017; 114:3445-50. [PMID: 28289208 DOI: 10.1073/pnas.1612284114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nearly all older men will experience lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), the etiology of which is not well understood. We have generated Stk11CKO mice by conditional deletion of the liver kinase B1 (LKB1) tumor suppressor gene, Stk11 (serine threonine kinase 11), in the fetal Müllerian duct mesenchyme (MDM), the caudal remnant of which is thought to be assimilated by the urogenital sinus primordial mesenchyme in males during fetal development. We show that MDM cells contribute to the postnatal stromal cells at the dorsal aspect of the prostatic urethra by lineage tracing. The Stk11CKO mice develop prostatic hyperplasia with bladder outlet obstruction, most likely because of stromal expansion. The stromal areas from prostates of Stk11CKO mice, with or without significant expansion, were estrogen receptor positive, which is consistent with both MD mesenchyme-derived cells and the purported importance of estrogen receptors in BPH development and/or progression. In some cases, stromal hyperplasia was admixed with epithelial metaplasia, sometimes with keratin pearls, consistent with squamous cell carcinomas. Mice with conditional deletion of both Stk11 and Pten developed similar features as the Stk11CKO mice, but at a highly accelerated rate, often within the first few months after birth. Western blot analyses showed that the loss of LKB1 and phosphatase and tensin homolog deleted on chromosome 10 (PTEN) induces activation of the phospho-5' adenosine monophosphate-activated protein kinase and phospho-AKT serine/threonine kinase 1 signaling pathways, as well as increased total and active β-catenin. These results suggest that activation of these signaling pathways can induce hyperplasia of the MD stroma, which could play a significant role in the etiology of human BPH.
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Huang J, Chen H, Wei Q, Zhang Z, Zhong Z, Xu Y. Downregulation of LKB1 promotes tumor progression and predicts unfavorable prognosis in patients with glioma. Oncol Lett 2017; 13:1688-1694. [PMID: 28454310 PMCID: PMC5403413 DOI: 10.3892/ol.2017.5631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 10/21/2016] [Indexed: 01/24/2023] Open
Abstract
The liver kinase B1 (LKB1)/5′-adenosine monophosphate-activated protein kinase pathway has been reported to facilitate glioma cell growth by improving growth conditions. To investigate the clinical significance of LKB1 in human gliomas western blot analysis and quantitative polymerase chain reaction experiments were performed. The present study demonstrated that LKB1 expression was markedly decreased at the messenger RNA and protein levels in 30 freshly prepared glioma tissues, compared with non-neoplastic brain tissues (P<0.001). Subsequently, immunohistochemical analysis demonstrated that LKB1 immunostaining in 180 glioma tissues was significantly decreased compared with that in the corresponding non-neoplastic brain tissues (P<0.001). Notably, this downregulation frequently occurred in high-grade gliomas, and statistical analysis revealed that low LKB1 expression was significantly associated with large tumor size (P=0.02), advanced World Health Organization grade (P=0.006) and low Karnofsky performance scale (P=0.01). The prognostic value of LKB1 expression in patients with glioma was additionally evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression models. As a result, the overall survival time of patients with glioma with low LKB1 expression was shorter compared with that of patients with high LKB1 expression (P<0.001), and low LKB1 expression also indicated decreased survival time in patients with high-grade glioma (P<0.001). Collectively, the present data indicated that the downregulation of LKB1 was closely associated with the malignant degree of human gliomas, exhibiting lower expression at a higher grade. Notably, LKB1 may serve as a potential prognostic biomarker for patients with glioma following surgery.
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Affiliation(s)
- Jiehao Huang
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Hongwu Chen
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Quantang Wei
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Ziheng Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Zhiwei Zhong
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
| | - Yimin Xu
- Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, P.R. China
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Li Z, Wang C, Zhu J, Bai Y, Wang W, Zhou Y, Zhang S, Liu X, Zhou S, Huang W, Bi Y, Wang H. The possible role of liver kinase B1 in hydroquinone-induced toxicity of murine fetal liver and bone marrow hematopoietic stem cells. Environ Toxicol 2016; 31:830-841. [PMID: 25534963 DOI: 10.1002/tox.22094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 12/02/2014] [Accepted: 12/07/2014] [Indexed: 06/04/2023]
Abstract
Epidemiological studies suggest that the increasing incidence of childhood leukemia may be due to maternal exposure to benzene, which is a known human carcinogen; however, the mechanisms involved remain unknown. Liver Kinase B1 (LKB1) acts as a regulator of cellular energy metabolism and functions to regulate hematopoietic stem cell (HSC) homeostasis. We hypothesize that LKB1 contributes to the deregulation of fetal or bone hematopoiesis caused by the benzene metabolite hydroquinone (HQ). To evaluate this hypothesis, we compared the effects of HQ on murine fetal liver hematopoietic stem cells (FL-HSCs) and bone marrow hematopoietic stem cells (BM-HSCs). FL-HSCs and BM-HSCs were isolated and enriched by a magnetic cell sorting system and exposed to various concentrations of HQ (0, 1.25, 2.5, 5, 10, 20, and 40 μM) for 24 h. We found that the inhibition of differentiation and growth, as well as the apoptosis rate of FL-HSCs, induced by HQ were consistent with the changes in BM-HSCs. Furthermore, G1 cell cycle arrest was observed in BM-HSCs and FL-HSCs in response to HQ. Importantly, FL-HSCs were more sensitive than BM-HSCs after exposure to HQ. The highest induction of LKB1 and adenosine monophosphate-activated protein kinase (AMPK) was observed with a much lower concentration of HQ in FL-HSCs than in BM-HSCs. LKB1 may play a critical role in apoptosis and cell cycle arrest of HQ-treated HSCs. This research has developed innovative ideas concerning benzene-induced hematopoietic toxicity or embryotoxicity, which can provide a new experimental evidence for preventing childhood leukemia. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 830-841, 2016.
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Affiliation(s)
- Zhen Li
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Chunhong Wang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Jie Zhu
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - YuE Bai
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Wei Wang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Yanfeng Zhou
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Shaozun Zhang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Xiangxiang Liu
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Sheng Zhou
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Wenting Huang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Yongyi Bi
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
| | - Hong Wang
- Department of Occupational and Environmental Health, School of Public Health, Wuhan University, Wuhan, Hubei, People's Republic of China
- Hubei Key Laboratory of Allergy and Immune-Related Diseases, Wuhan, Hubei, People's Republic of China
- Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan, Hubei, People's Republic of China
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Liu P, Cheng GC, Ye QH, Deng YZ, Wu L. LKB1/AMPK pathway mediates resistin-induced cardiomyocyte hypertrophy in H9c2 embryonic rat cardiomyocytes. Biomed Rep 2016; 4:387-391. [PMID: 26998282 DOI: 10.3892/br.2016.593] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 01/27/2016] [Indexed: 12/11/2022] Open
Abstract
Resistin has been previously demonstrated to induce cardiac hypertrophy, however, the underlying molecular mechanisms of resistin-induced cardiac hypertrophy remain unclear. Using H9c2 cells, the present study investigated the liver kinase B1 (LKB1)/adenosine monophosphate-activated protein kinase (AMPK) signaling pathway for a potential role in mediating resistin-induced cardiomyocyte hypertrophy. Treatment of H9c2 cells with resistin increased cell surface area, protein synthesis, and expression of hypertrophic marker brain natriuretic peptide and β-myosin heavy chain. Treatment with metformine attenuated these effects of resistin. Furthermore, treatment with resistin decreased phosphorylation of LKB1 and AMPK, whereas pretreatment with metformin increased phosphorylation of LKB1 and AMPK that is reduced by resistin. These results suggest that resistin induces cardiac hypertrophy through the inactivation of the LKB1/AMPK cell signaling pathway.
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Affiliation(s)
- Peng Liu
- Department of Cardiovascular Surgery, The Affiliated Cardiovascular Hospital of Shanxi Medical University, and Shanxi Cardiovascular Hospital (Institute), Taiyuan, Shanxi 030024, P.R. China
| | - Guan-Chang Cheng
- Department of Cardiology, Huaihe Hospital of Henan University, Kaifeng, Henan 475000, P.R. China
| | - Qun-Hui Ye
- Department of Cardiology, Huaihe Hospital of Henan University, Kaifeng, Henan 475000, P.R. China
| | - Yong-Zhi Deng
- Department of Cardiovascular Surgery, The Affiliated Cardiovascular Hospital of Shanxi Medical University, and Shanxi Cardiovascular Hospital (Institute), Taiyuan, Shanxi 030024, P.R. China
| | - Lin Wu
- Department of Cardiology, Huaihe Hospital of Henan University, Kaifeng, Henan 475000, P.R. China
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Sid V, Wu N, Sarna LK, Siow YL, House JD, O K. Folic acid supplementation during high-fat diet feeding restores AMPK activation via an AMP-LKB1-dependent mechanism. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1215-25. [PMID: 26400185 DOI: 10.1152/ajpregu.00260.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022]
Abstract
AMPK is an endogenous energy sensor that regulates lipid and carbohydrate metabolism. Nonalcoholic fatty liver disease (NAFLD) is regarded as a hepatic manifestation of metabolic syndrome with impaired lipid and glucose metabolism and increased oxidative stress. Our recent study showed that folic acid supplementation attenuated hepatic oxidative stress and lipid accumulation in high-fat diet-fed mice. The aim of the present study was to investigate the effect of folic acid on hepatic AMPK during high-fat diet feeding and the mechanisms involved. Male C57BL/6J mice were fed a control diet (10% kcal fat), a high-fat diet (60% kcal fat), or a high-fat diet supplemented with folic acid (26 mg/kg diet) for 5 wk. Mice fed a high-fat diet exhibited hyperglycemia, hepatic cholesterol accumulation, and reduced hepatic AMPK phosphorylation. Folic acid supplementation restored AMPK phosphorylation (activation) and reduced blood glucose and hepatic cholesterol levels. Activation of AMPK by folic acid was mediated through an elevation of its allosteric activator AMP and activation of its upstream kinase, namely, liver kinase B1 (LKB1) in the liver. Consistent with in vivo findings, 5-methyltetrahydrofolate (bioactive form of folate) restored phosphorylation (activation) of both AMPK and LKB1 in palmitic acid-treated HepG2 cells. Activation of AMPK by folic acid might be responsible for AMPK-dependent phosphorylation of HMG-CoA reductase, leading to reduced hepatic cholesterol synthesis during high-fat diet feeding. These results suggest that folic acid supplementation may improve cholesterol and glucose metabolism by restoration of AMPK activation in the liver.
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Affiliation(s)
- Victoria Sid
- St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, Winnipeg, Manitoba, Canada
| | - Nan Wu
- St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, Winnipeg, Manitoba, Canada
| | - Lindsei K Sarna
- St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada; Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Yaw L Siow
- St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, Winnipeg, Manitoba, Canada; Agriculture and Agri-Food Canada, Winnipeg, Manitoba, Canada; and
| | - James D House
- Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada; Department of Human Nutritional Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Karmin O
- St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada; Department of Physiology and Pathophysiology, Winnipeg, Manitoba, Canada; Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, Canada;
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37
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Boullerne AI, Skias D, Hartman EM, Testai FD, Kalinin S, Polak PE, Feinstein DL. A single-nucleotide polymorphism in serine-threonine kinase 11, the gene encoding liver kinase B1, is a risk factor for multiple sclerosis. ASN Neuro 2015; 7:1759091415568914. [PMID: 25694554 PMCID: PMC4342367 DOI: 10.1177/1759091415568914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
We identified a family in which five siblings were diagnosed with multiple sclerosis (MS) or clinically isolated syndrome. Several women in the maternal lineage have comorbidities typically associated with Peutz Jeghers Syndrome, a rare autosomal-dominant disease caused by mutations in the serine-threonine-kinase 11 (STK11) gene, which encodes liver kinase B1. Sequence analysis of DNA from one sibling identified a single-nucleotide polymorphism (SNP) within STK11 intron 5. This SNP (dbSNP ID: rs9282860) was identified by TaqMan polymerase chain reaction (PCR) assays in DNA samples available from two other siblings. Further screening was carried out in samples from 654 relapsing-remitting MS patients, 100 primary progressive MS patients, and 661 controls. The STK11-SNP has increased frequency in all female patients versus controls (odds ratio = 1.66, 95% CI = 1.05, 2.64, p = .032). The STK11-SNP was not associated with disease duration or onset; however, it was significantly associated with reduced severity (assessed by MS severity scores), with the lowest scores in patients who also harbored the HLA-DRB1*1501 allele. In vitro studies showed that peripheral blood mononuclear cells from members of the family were more sensitive to the mitochondrial inhibitor metformin than cells from MS patients with the major STK11 allele. The increased association of SNP rs9282860 in women with MS defines this variant as a genetic risk factor. The lower disease severity observed in the context of HLA-DRB1*1501 combined with limited in vitro studies raises the provocative possibility that cells harboring the STK11-SNP could be targeted by drugs which increase metabolic stress.
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Affiliation(s)
- Anne I Boullerne
- Department of Anesthesiology, University of Illinois at Chicago, IL, USA
| | - Demetrios Skias
- Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL, USA Department of Neurology, University of Illinois at Chicago, IL, USA
| | | | | | - Sergey Kalinin
- Department of Anesthesiology, University of Illinois at Chicago, IL, USA
| | - Paul E Polak
- Department of Anesthesiology, University of Illinois at Chicago, IL, USA
| | - Douglas L Feinstein
- Department of Anesthesiology, University of Illinois at Chicago, IL, USA Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, IL, USA
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Xia C, Ye F, Hu X, Li Z, Jiang B, Fu Y, Cheng X, Shao Z, Zhuang Z. Liver kinase B1 enhances chemoresistance to gemcitabine in breast cancer MDA-MB-231 cells. Oncol Lett 2014; 8:2086-2092. [PMID: 25295095 PMCID: PMC4186618 DOI: 10.3892/ol.2014.2446] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 06/19/2014] [Indexed: 11/08/2022] Open
Abstract
Liver kinase B1 (LKB1) is a well-known tumor suppressor gene in a variety of human cancers, including breast cancer. However, its role in gemcitabine resistance is unclear. Since gemcitabine in combination with other chemotherapeutic reagents is the first-line treatment in advanced breast cancer, the aim of the present study was to determine the effect of ectopic expression of LKB1 on chemosensitivity to gemcitabine in the breast cancer MDA-MB-231 cell line. Increasing the expression of LKB1 was found to directly correlate with gemcitabine chemoresistance. Although LKB1 suppressed the cell proliferation rate and clonogenicity in the absence of gemcitabine, it increased the median inhibitory concentration of gemcitabine and clonogenicity of cells in the presence of gemcitabine. Mechanistic analysis indicated that LKB1 was able to protect cells from DNA damage caused by gemcitabine. Furthermore, it was found that LKB1 induced a significant upregulation of cytidine deaminase expression, an important enzyme that accelerates gemcitabine catabolization. Overall, dual characteristics of LKB1 were identified: Suppressing cell growth in normal conditions and enhancing chemoresisitance to gemcitabine, possibly by accelerating degradation of gemcitabine, and protecting cells from DNA damage caused by gemcitabine.
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Affiliation(s)
- Chen Xia
- Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University, School of Medicine, Shanghai 200040, P.R. China
| | - Fugui Ye
- Department of General Surgery, Affiliated Union Hospital of Fujian Medical University, Union Clinical School, Fujian Medical University, Fuzhou, Fujian 350001, P.R. China
| | - Xin Hu
- Department of Breast Surgery, Cancer Center and Cancer Institute, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
| | - Zhengdong Li
- Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University, School of Medicine, Shanghai 200040, P.R. China
| | - Beiqi Jiang
- Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University, School of Medicine, Shanghai 200040, P.R. China
| | - Yun Fu
- Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University, School of Medicine, Shanghai 200040, P.R. China
| | - Xiaolin Cheng
- Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University, School of Medicine, Shanghai 200040, P.R. China
| | - Zhiming Shao
- Department of Breast Surgery, Cancer Center and Cancer Institute, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China
| | - Zhigang Zhuang
- Department of Breast Surgery, Shanghai First Maternity and Infant Hospital, Tongji University, School of Medicine, Shanghai 200040, P.R. China
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Zhu J, Ning RB, Lin XY, Chai DJ, Xu CS, Xie H, Zeng JZ, Lin JX. Retinoid X receptor agonists inhibit hypertension-induced myocardial hypertrophy by modulating LKB1/AMPK/p70S6K signaling pathway. Am J Hypertens 2014; 27:1112-24. [PMID: 24603314 DOI: 10.1093/ajh/hpu017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Retinoid X receptor (RXR) has been demonstrated to play an important role in cardiac development and has been implicated in cardiovascular diseases. This study aimed to examine the effects of RXRα agonist bexarotene on pathological left ventricular hypertrophy (LVH) in a spontaneously hypertensive rat (SHR) model and the underlying mechanism. METHODS WKY rats served as controls. SHRs were randomized into 3 groups at the age of 4 weeks and were treated (once daily for 12 weeks) with either bexarotene (30 or 100mg/kg body weight) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Neonatal cardiomyocytes were treated with AngII (10(-7) mmol/L) with or without the indicated concentration of RXRα ligand 9-cis-RA. The protein abundances of β-actin, RXRα, LKB1, phospho-LKB1, AMPK, phospho-AMPK, P70S6K, phospho-P70S6K, ACE, and AT1 receptor were measured along with blood pressure, body weight and angiotensin II (Ang II) levels. The effects of LKB1 downregulation by LKB1 small, interfering RNA were examined. RESULTS Treatment of SHRs with bexarotene resulted in significant inhibition of LVH without eliminating hypertension. Immunoblot with heart tissue homogenates from SHRs revealed that bexarotene activated the LKB1/AMPK signaling pathway and inhibited p70S6K. However, the increased Ang II levels in SHR serum and heart tissue were not reduced by bexarotene treatment. Treatment of cardiomyocytes with Ang II resulted in significantly reduced LKB1/AMPK activity and increased p70S6K activity. 9-cis-RA antagonized Ang II-induced LKB1/AMPK and p70S6K activation changes in vitro. CONCLUSIONS RXR agonists prevent the inhibition of the LKB1/AMPK/p70S6K pathway and regulate protein synthesis to reduce LVH. This antihypertrophic effect of bexarotene is independent of blood pressure.
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Affiliation(s)
- Jiang Zhu
- First Clinical Medical College, Fujian Medical University, Fuzhou, Fujian, China
| | - Ruo-Bing Ning
- First Clinical Medical College, Fujian Medical University, Fuzhou, Fujian, China
| | - Xiao-Yan Lin
- Echocardiological Department, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China
| | - Da-Jun Chai
- Cardiovascular Department, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China;
| | - Chang-Sheng Xu
- Cardiovascular Department, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China
| | - Hong Xie
- Cardiovascular Department, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China
| | - Jin-Zhang Zeng
- School of Pharmaceutical Sciences and Institute for Biomedical Research, Xiamen University, Xiamen, China
| | - Jin-Xiu Lin
- Cardiovascular Department, First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, China;
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Ramamurthy S, Chang E, Cao Y, Zhu J, Ronnett GV. AMPK activation regulates neuronal structure in developing hippocampal neurons. Neuroscience 2013; 259:13-24. [PMID: 24295634 DOI: 10.1016/j.neuroscience.2013.11.048] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/21/2013] [Accepted: 11/23/2013] [Indexed: 12/25/2022]
Abstract
AMP-activated protein kinase (AMPK) is a serine/threonine kinase that functions as a cellular and whole organism energy sensor to regulate ATP-consuming (anabolic) and ATP-generating (catabolic) pathways. The heterotrimeric AMPK complex consists of a catalytic α-subunit, regulatory β-subunit, and an AMP/ATP-binding γ-subunit. Several alternate isoforms exist for each subunit (α1, α2, β1, β2, γ1, γ2 and γ3). However, little is known of the expression pattern or function of the individual catalytic complexes in regulating neuronal structure. In this study, we examined the role of AMPK subunits in differentiating hippocampal neurons. We found that during development, the expression of AMPK subunits increase and that activation of AMPK by energetic stress inhibits neuronal development at multiple stages, not only during axon outgrowth, but also during dendrite growth and arborization. The presence of a single functional AMPK catalytic complex was sufficient to mediate these inhibitory effects of energetic stress. Activation of AMPK mediates these effects by suppressing both the mTOR and Akt signaling pathways. These findings demonstrate that the energy-sensing AMPK pathway regulates neuronal structure in distinct regions of developing neurons at multiple stages of development.
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Affiliation(s)
- S Ramamurthy
- Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA
| | - E Chang
- Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA
| | - Y Cao
- Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA
| | - J Zhu
- Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA
| | - G V Ronnett
- Department of Neuroscience, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Department of Biological Chemistry, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, 855 N Wolfe Street, Baltimore, MD 21205, USA; Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea.
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Cordero-Herrera I, Martín MÁ, Goya L, Ramos S. Cocoa flavonoids attenuate high glucose-induced insulin signalling blockade and modulate glucose uptake and production in human HepG2 cells. Food Chem Toxicol 2014; 64:10-9. [PMID: 24262486 DOI: 10.1016/j.fct.2013.11.014] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/05/2013] [Accepted: 11/12/2013] [Indexed: 12/25/2022]
Abstract
Insulin resistance is the primary characteristic of type 2 diabetes. Cocoa and its main flavanol, (-)-epicatechin (EC), display some antidiabetic effects, but the mechanisms for their preventive activities related to glucose metabolism and insulin signalling in the liver remain largely unknown. In the present work, the preventive effect of EC and a cocoa polyphenolic extract (CPE) on insulin signalling and on both glucose production and uptake are studied in insulin-responsive human HepG2 cells treated with high glucose. Pre-treatment of cells with EC or CPE reverted decreased tyrosine-phosphorylated and total levels of IR, IRS-1 and -2 triggered by high glucose. EC and CPE pre-treatment also prevented the inactivation of the PI3K/AKT pathway and AMPK, as well as the diminution of GLUT-2 levels induced by high glucose. Furthermore, pre-treatment of cells with EC and CPE avoided the increase in PEPCK levels and the diminished glucose uptake provoked by high glucose, returning enhanced levels of glucose production and decreased glycogen content to control values. These findings suggest that EC and CPE improved insulin sensitivity of HepG2 treated with high glucose, preventing or delaying a potential hepatic dysfunction through the attenuation of the insulin signalling blockade and the modulation of glucose uptake and production.
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42
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Tanner CB, Madsen SR, Hallowell DM, Goring DMJ, Moore TM, Hardman SE, Heninger MR, Atwood DR, Thomson DM. Mitochondrial and performance adaptations to exercise training in mice lacking skeletal muscle LKB1. Am J Physiol Endocrinol Metab 2013; 305:E1018-29. [PMID: 23982155 PMCID: PMC3798697 DOI: 10.1152/ajpendo.00227.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
LKB1 and its downstream targets of the AMP-activated protein kinase family are important regulators of many aspects of skeletal muscle cell function, including control of mitochondrial content and capillarity. LKB1 deficiency in skeletal and cardiac muscle (mLKB1-KO) greatly impairs exercise capacity. However, cardiac dysfunction in that genetic model prevents a clear assessment of the role of skeletal muscle LKB1 in the observed effects. Our purposes here were to determine whether skeletal muscle-specific knockout of LKB1 (skmLKB1-KO) decreases exercise capacity and mitochondrial protein content, impairs accretion of mitochondrial proteins after exercise training, and attenuates improvement in running performance after exercise training. We found that treadmill and voluntary wheel running capacity was reduced in skmLKB1-KO vs. control (CON) mice. Citrate synthase activity, succinate dehydrogenase activity, and pyruvate dehydrogenase kinase content were lower in KO vs. CON muscles. Three weeks of treadmill training resulted in significantly increased treadmill running performance in both CON and skmLKB1-KO mice. Citrate synthase activity increased significantly with training in both genotypes, but protein content and activity for components of the mitochondrial electron transport chain increased only in CON mice. Capillarity and VEGF protein was lower in skmLKB1-KO vs. CON muscles, but VEGF increased with training only in skmLKB1-KO. Three hours after an acute bout of muscle contractions, PGC-1α, cytochrome c, and VEGF gene expression all increased in CON but not skmLKB1-KO muscles. Our findings indicate that skeletal muscle LKB1 is required for accretion of some mitochondrial proteins but not for early exercise capacity improvements with exercise training.
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MESH Headings
- AMP-Activated Protein Kinases
- Adaptation, Physiological
- Animals
- Capillaries/physiology
- Citrate (si)-Synthase/metabolism
- Citric Acid Cycle
- Female
- Gene Expression Regulation, Enzymologic
- Male
- Mice
- Mice, Knockout
- Mitochondria, Muscle/enzymology
- Mitochondria, Muscle/metabolism
- Motor Activity
- Motor Skills
- Muscle, Skeletal/blood supply
- Muscle, Skeletal/cytology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Pyruvate Dehydrogenase Acetyl-Transferring Kinase
- RNA, Messenger/metabolism
- Succinate Dehydrogenase/metabolism
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Colby B Tanner
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah
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Li S, Li J, Shen C, Zhang X, Sun S, Cho M, Sun C, Song Z. tert-Butylhydroquinone (tBHQ) protects hepatocytes against lipotoxicity via inducing autophagy independently of Nrf2 activation. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:22-33. [PMID: 24055888 DOI: 10.1016/j.bbalip.2013.09.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 08/23/2013] [Accepted: 09/10/2013] [Indexed: 12/30/2022]
Abstract
Saturated fatty acids (SFAs) induce hepatocyte cell death, wherein oxidative stress is mechanistically involved. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a master transcriptional regulator of cellular antioxidant defense enzymes. Therefore, Nrf2 activation is regarded as an effective strategy against oxidative stress-triggered cellular damage. In this study, tert-butylhydroquinone (tBHQ), a widely used Nrf2 activator, was initially employed to investigate the potential protective role of Nrf2 activation in SFA-induced hepatoxicity. As expected, SFA-induced hepatocyte cell death was prevented by tBHQ in both AML-12 mouse hepatocytes and HepG2 human hepatoma cells. However, the protective effect of tBHQ is Nrf2-independent, because the siRNA-mediated Nrf2 silencing did not abrogate tBHQ-conferred protection. Alternatively, our results revealed that autophagy activation was critically involved in the protective effect of tBHQ on lipotoxicity. tBHQ induced autophagy activation and autophagy inhibitors abolished tBHQ's protection. The induction of autophagy by tBHQ exposure was demonstrated by the increased accumulation of LC3 puncta, LC3-II conversion, and autophagic flux (LC3-II conversion in the presence of proteolysis inhibitors). Subsequent mechanistic investigation discovered that tBHQ exposure activated AMP-activated protein kinase (AMPK) and siRNA-mediated AMPK gene silencing abolished tBHQ-induced autophagy activation, indicating that AMPK is critically involved in tBHQ-triggered autophagy induction. Furthermore, our study provided evidence that tBHQ-induced autophagy activation is required for its Nrf2-activating property. Collectively, our data uncover a novel mechanism for tBHQ in protecting hepatocytes against SFA-induced lipotoxicity. tBHQ-triggered autophagy induction contributes not only to its hepatoprotective effect, but also to its Nrf2-activating property.
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Affiliation(s)
- Songtao Li
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612, USA; Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin 150081, PR China
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Shackelford DB. Unravelling the connection between metabolism and tumorigenesis through studies of the liver kinase B1 tumour suppressor. J Carcinog 2013; 12:16. [PMID: 24082825 PMCID: PMC3779404 DOI: 10.4103/1477-3163.116323] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/12/2013] [Indexed: 12/15/2022] Open
Abstract
The liver kinase B1 (LKB1) tumour suppressor functions as a master regulator of growth, metabolism and survival in cells, which is frequently mutated in sporadic human non-small cell lung and cervical cancers. LKB1 functions as a key upstream activator of the AMP-activated protein kinase (AMPK), a central metabolic switch found in all eukaryotes that govern glucose and lipid metabolism and autophagy in response to alterations in nutrients and intracellular energy levels. The LKB1/AMPK signalling pathway suppresses mammalian target of rapamycin complex 1 (mTORC1), an essential regulator of cell growth in all eukaryotes that is deregulated in a majority of human cancers. LKB1 inactivation in cancer leads to both tumorigenesis and metabolic deregulation through the AMPK and mTORC1-signalling axis and there remain critical challenges to elucidate the direct role LKB1 inactivation plays in driving aberrant metabolism and tumour growth. This review addresses past and current efforts to delineate the molecular mechanisms fueling metabolic deregulation and tumorigenesis following LKB1 inactivation as well as translational promise of therapeutic strategies aimed at targeting LKB1-deficient tumors.
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Affiliation(s)
- David B Shackelford
- Department of Pulmonary and Critical Care Medicine, David Geffen School of Medicine at University of California, Los Angeles, California, USA
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45
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Ekizoglu S, Dalay N, Karaman E, Akdeniz D, Ozaydin A, Buyru N. LKB1 downregulation may be independent of promoter methylation or FOXO3 expression in head and neck cancer. Transl Res 2013; 162:122-9. [PMID: 23810581 DOI: 10.1016/j.trsl.2013.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 05/30/2013] [Accepted: 06/03/2013] [Indexed: 01/29/2023]
Abstract
The serine/threonine kinase liver kinase B 1 (LKB1) is a multifunctional protein and has been associated with various cancer types. Although the tumor suppressor function of LKB1 is attributed mainly to its ability to phosphorylate directly different adenosine monophosphate-activated protein kinases, its regulation is still poorly understood. More recently, it has been shown that LKB1 expression can be regulated by forkhead box O transcription factors via cis-acting elements, which are found in the promoter region of the LKB1 gene. In this study, we investigated LKB1 messenger RNA expression levels in association with the promoter methylation of the gene and forkhead box O member 3 (FOXO3) messenger RNA expression in head and neck squamous cell carcinoma (HNSCC) tumor samples. Our results show that LKB1 expression is downregulated, especially in advanced-stage tumor samples, and this downregulation was not the result of promoter methylation or modulation by FOXO3 (P = 0.656). Despite observing a positive association between the LKB1 and FOXO3 expression levels in the tumors, this association was not statistically significant (P = 0.24). Our results indicate that downregulation of LKB1 is independent of FOXO3 and may be implicated in the progression of HNSCC.
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Miura S, Kai Y, Tadaishi M, Tokutake Y, Sakamoto K, Bruce CR, Febbraio MA, Kita K, Chohnan S, Ezaki O. Marked phenotypic differences of endurance performance and exercise-induced oxygen consumption between AMPK and LKB1 deficiency in mouse skeletal muscle: changes occurring in the diaphragm. Am J Physiol Endocrinol Metab 2013; 305:E213-29. [PMID: 23695215 DOI: 10.1152/ajpendo.00114.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
LKB1 phosphorylates members of the AMP-activated protein kinase (AMPK) family. LKB1 and AMPK in the skeletal muscle are believed to regulate not only fuel oxidation during exercise but also exercise capacity. LKB1 was also required to prevent diaphragm fatigue, which was shown to affect exercise performance. Using mice expressing dominant negative (DN) mutants of LKB1 and AMPK, specifically in the skeletal muscle but not in the heart, we investigated the roles of LKB1 and AMPK activity in exercise performance and the effects of these kinases on the characteristics of respiratory and locomotive muscles. In the diaphragm and gastrocnemius, both AMPK-DN and LKB1-DN mice showed complete loss of AMPKα2 activity, and LKB1-DN mice showed a reduction in LKB1 activity. Exercise capacity was significantly reduced in LKB1-DN mice, with a marked reduction in oxygen consumption and carbon dioxide production during exercise. The diaphragm from LKB1-DN mice showed an increase in myosin heavy chain IIB and glycolytic enzyme expression. Normal respiratory chain function and CPT I activity were shown in the isolated mitochondria from LKB1-DN locomotive muscle, and the expression of genes related to fiber type, mitochondria function, glucose and lipid metabolism, and capillarization in locomotive muscle was not different between LKB1-DN and AMPK-DN mice. We concluded that LKB1 in the skeletal muscle contributes significantly to exercise capacity and oxygen uptake during exercise. LKB1 mediated the change of fiber-type distribution in the diaphragm independently of AMPK and might be responsible for the phenotypes we observed.
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Affiliation(s)
- Shinji Miura
- Laboratory of Nutritional Biochemistry, Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
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Aki T, Funakoshi T, Unuma K, Uemura K. Impairment of autophagy: from hereditary disorder to drug intoxication. Toxicology 2013; 311:205-15. [PMID: 23851159 DOI: 10.1016/j.tox.2013.07.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 06/30/2013] [Accepted: 07/01/2013] [Indexed: 12/11/2022]
Abstract
At first, the molecular mechanism of autophagy was unveiled in a unicellular organism Saccharomyces cerevisiae (budding yeast), followed by the discovery that the basic mechanism of autophagy is conserved in multicellular organisms including mammals. Although autophagy was considered to be a non-selective bulk protein degradation system to recycle amino acids during periods of nutrient starvation, it is also believed to be an essential mechanism for the selective elimination of proteins/organelles that are damaged under pathological conditions. Research advances made using autophagy-deficient animals have revealed that impairments of autophagy often underlie the pathogenesis of hereditary disorders such as Danon, Parkinson's, Alzheimer's, and Huntington's diseases, and amyotrophic lateral sclerosis. On the other hand, there are many reports that drugs and toxicants, including arsenic, cadmium, paraquat, methamphetamine, and ethanol, induce autophagy during the development of their toxicity on many organs including heart, brain, lung, kidney, and liver. Although the question as to whether autophagic machinery is involved in the execution of cell death or not remains controversial, the current view of the role of autophagy during cell/tissue injury is that it is an important, often essential, cytoprotective reaction; disturbances in cytoprotective autophagy aggravate cell/tissue injuries. The purpose of this review is to provide (1) a gross summarization of autophagy processes, which are becoming more important in the field of toxicology, and (2) examples of important studies reporting the involvement of perturbations in autophagy in cell/tissue injuries caused by acute as well as chronic intoxication.
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Affiliation(s)
- Toshihiko Aki
- Section of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8519, Japan.
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Filippov S, Pinkosky SL, Lister RJ, Pawloski C, Hanselman JC, Cramer CT, Srivastava RAK, Hurley TR, Bradshaw CD, Spahr MA, Newton RS. ETC-1002 regulates immune response, leukocyte homing, and adipose tissue inflammation via LKB1-dependent activation of macrophage AMPK. J Lipid Res 2013; 54:2095-2108. [PMID: 23709692 DOI: 10.1194/jlr.m035212] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ETC-1002 is an investigational drug currently in Phase 2 development for treatment of dyslipidemia and other cardiometabolic risk factors. In dyslipidemic subjects, ETC-1002 not only reduces plasma LDL cholesterol but also significantly attenuates levels of hsCRP, a clinical biomarker of inflammation. Anti-inflammatory properties of ETC-1002 were further investigated in primary human monocyte-derived macrophages and in in vivo models of inflammation. In cells treated with ETC-1002, increased levels of AMP-activated protein kinase (AMPK) phosphorylation coincided with reduced activity of MAP kinases and decreased production of proinflammatory cytokines and chemokines. AMPK phosphorylation and inhibitory effects of ETC-1002 on soluble mediators of inflammation were significantly abrogated by siRNA-mediated silencing of macrophage liver kinase B1 (LKB1), indicating that ETC-1002 activates AMPK and exerts its anti-inflammatory effects via an LKB1-dependent mechanism. In vivo, ETC-1002 suppressed thioglycollate-induced homing of leukocytes into mouse peritoneal cavity. Similarly, in a mouse model of diet-induced obesity, ETC-1002 restored adipose AMPK activity, reduced JNK phosphorylation, and diminished expression of macrophage-specific marker 4F/80. These data were consistent with decreased epididymal fat-pad mass and interleukin (IL)-6 release by inflamed adipose tissue. Thus, ETC-1002 may provide further clinical benefits for patients with cardiometabolic risk factors by reducing systemic inflammation linked to insulin resistance and vascular complications of metabolic syndrome.
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Xu L, Kanasaki M, He J, Kitada M, Nagao K, Jinzu H, Noguchi Y, Maegawa H, Kanasaki K, Koya D. Ketogenic essential amino acids replacement diet ameliorated hepatosteatosis with altering autophagy-associated molecules. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1605-12. [PMID: 23669346 DOI: 10.1016/j.bbadis.2013.05.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 05/03/2013] [Accepted: 05/06/2013] [Indexed: 02/06/2023]
Abstract
Ketogenic amino acid (KAA) replacement diet has been shown to cure hepatic steatosis, a serious liver disease associated with diverse metabolic defects. In this study, we investigated the effects of KAA replacement diet on nutrition sensing signaling pathway and analyzed whether induction of hepatic autophagy was involved. Mice are fed with high fat diet (HFD) or KAA replacement in high-fat diet (30% fat in food; HFD)-fed (HFD(KAAR)) and sacrificed at 8, 12, 16 weeks after initiation of experimental food. Hepatic autophagy was analyzed in protein expression of several autophagy-associated molecules and in light chain-3 green fluorescent protein (LC-3 GFP) transgenic mice. HFD(KAAR) showed increased AMP-activated protein kinase (AMPK) phosphorylation and enhanced liver kinase B1 (LKB1) expression compared to control HFD-fed mice. The KAA-HFD-induced activation of AMPK was associated with an increased protein expression of sirtuin 1 (Sirt1), decreased forkhead box protein O3a (Foxo3a) level, and suppression of mammalian target of rapamycin (mTOR) phosphorylation compared with the HFD-fed mice. The intervention study revealed that a KAA-replacement diet also ameliorated all the established metabolic and autophagy defects in the HFD-fed mice, suggesting that a KAA-replacement diet can be used therapeutically in established diseases. These results indicate that KAA replacement in food could be a novel strategy to combat hepatic steatosis and metabolic abnormalities likely involvement of an induction of autophagy.
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Shearn CT, Smathers RL, Jiang H, Orlicky DJ, Maclean KN, Petersen DR. Increased dietary fat contributes to dysregulation of the LKB1/AMPK pathway and increased damage in a mouse model of early-stage ethanol-mediated steatosis. J Nutr Biochem 2013; 24:1436-45. [PMID: 23465594 DOI: 10.1016/j.jnutbio.2012.12.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 11/30/2012] [Accepted: 12/06/2012] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The objective of the study was to examine the interaction of moderate and high dietary fat and ethanol with respect to formation of steatosis and regulation of the AMP-activated protein kinase (AMPK) pathway in a mouse model of chronic ethanol consumption. METHODS Male C57BL/6J mice were pair-fed a modified Lieber-DeCarli diet composed of either moderate fat [30% fat-derived calories (MF)] or high fat [45% fat-derived calories (HF)] combined with increasing concentrations of ethanol (2%-6%) for 6 weeks. RESULTS Chronic ethanol consumption resulted in significant increases in plasma alanine aminotransferase in MF (1.84-fold) and HF mice (2.33-fold), yet liver triglycerides only increased significantly in the HF model (1.62-fold). Ethanol addition significantly increased plasma adiponectin under conditions of MF but not HF. In combination with MF, the addition of ethanol significantly decreased total and hepatic pThr(172)AMPKα and acetyl CoA Carboxylase (ACC). HF plus ethanol decreased pSer(108)AMPKβ, yet a marked 1.5-fold increase in pThr(172)AMPKα occurred. No change was evident in pSer(79)ACC under conditions of ethanol and HF ingestion. In both models, nuclear levels of sterol response element binding protein 1c and carbohydrate response element binding protein were decreased. Surprisingly, MF plus ethanol significantly elevated protein expression of medium-chain acyl-CoA dehydrogenase (MCAD), long-chain acyl-CoA dehydrogenase (LCAD) and very long chain acyl-CoA dehydrogenase but did not significantly affect mRNA expression of other proteins involved in β-oxidation and fatty acid synthesis. HF plus ethanol significantly reduced mRNA expression of both stearoyl CoA desaturase 1 and fatty acid elongase 5, but did not have an effect on MCAD or LCAD. CONCLUSION These data suggest that, when co-ingested with ethanol, dietary fat differentially contributes to dysregulation of adiponectin-dependent activation of the AMPK pathway in the liver of mice.
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