1
|
Achanta LB, Thomas DS, Housley GD, Rae CD. AMP-activated protein kinase activators have compound and concentration-specific effects on brain metabolism. J Neurochem 2024; 168:677-692. [PMID: 36977628 DOI: 10.1111/jnc.15815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023]
Abstract
AMP-activated protein kinase (AMPK) is a key sensor of energy balance playing important roles in the balancing of anabolic and catabolic activities. The high energy demands of the brain and its limited capacity to store energy indicate that AMPK may play a significant role in brain metabolism. Here, we activated AMPK in guinea pig cortical tissue slices, both directly with A769662 and PF 06409577 and indirectly with AICAR and metformin. We studied the resultant metabolism of [1-13C]glucose and [1,2-13C]acetate using NMR spectroscopy. We found distinct activator concentration-dependent effects on metabolism, which ranged from decreased metabolic pool sizes at EC50 activator concentrations with no expected stimulation in glycolytic flux to increased aerobic glycolysis and decreased pyruvate metabolism with certain activators. Further, activation with direct versus indirect activators produced distinct metabolic outcomes at both low (EC50) and higher (EC50 × 10) concentrations. Specific direct activation of β1-containing AMPK isoforms with PF 06409577 resulted in increased Krebs cycle activity, restoring pyruvate metabolism while A769662 increased lactate and alanine production, as well as labelling of citrate and glutamine. These results reveal a complex metabolic response to AMPK activators in brain beyond increased aerobic glycolysis and indicate that further research is warranted into their concentration- and mechanism-dependent impact.
Collapse
Affiliation(s)
- Lavanya B Achanta
- Neuroscience Research Australia, Barker St, Randwick, New South Wales, 2031, Australia
- Translational Neuroscience Facility, School of Biomedical Sciences, UNSW, Sydney, New South Wales, 2052, Australia
| | - Donald S Thomas
- Mark Wainwright Analytical Centre, UNSW, Sydney, New South Wales, 2052, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, School of Biomedical Sciences, UNSW, Sydney, New South Wales, 2052, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Barker St, Randwick, New South Wales, 2031, Australia
- School of Psychology, UNSW, Sydney, New South Wales, 2052, Australia
| |
Collapse
|
2
|
Duranti E, Villa C. Muscle Involvement in Amyotrophic Lateral Sclerosis: Understanding the Pathogenesis and Advancing Therapeutics. Biomolecules 2023; 13:1582. [PMID: 38002264 PMCID: PMC10669302 DOI: 10.3390/biom13111582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal condition characterized by the selective loss of motor neurons in the motor cortex, brainstem, and spinal cord. Muscle involvement, muscle atrophy, and subsequent paralysis are among the main features of this disease, which is defined as a neuromuscular disorder. ALS is a persistently progressive disease, and as motor neurons continue to degenerate, individuals with ALS experience a gradual decline in their ability to perform daily activities. Ultimately, muscle function loss may result in paralysis, presenting significant challenges in mobility, communication, and self-care. While the majority of ALS research has traditionally focused on pathogenic pathways in the central nervous system, there has been a great interest in muscle research. These studies were carried out on patients and animal models in order to better understand the molecular mechanisms involved and to develop therapies aimed at improving muscle function. This review summarizes the features of ALS and discusses the role of muscle, as well as examines recent studies in the development of treatments.
Collapse
Affiliation(s)
| | - Chiara Villa
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy;
| |
Collapse
|
3
|
Bai Y, Hei N, Gao M, Dong X, Li M, Jiang S, Zhang L. LDLR heterozygous deletion reduces hamster testicular cholesterol toxicity via AMPK/Sirt1/PGC-1α pathway. Toxicol Lett 2023; 384:30-43. [PMID: 37459939 DOI: 10.1016/j.toxlet.2023.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/27/2023] [Accepted: 07/11/2023] [Indexed: 07/22/2023]
Abstract
Cholesterol is an important part of the human diet. The relationship and molecular mechanisms between intracellular cholesterol and male infertility are unclear. The purpose of this study was to evaluate the role of low-density lipoprotein receptor (LDLR) in male infertility. Both wild-type (WT) and LDLR heterozygous deletion (LDLR+/-) male Golden Syrian hamsters were fed either a high-fat diet (HFD) or a normal diet (ND). Plasma biochemistry, serum hormone, testicular histopathology, mRNA and protein expression of AMPK/Sirt1/PGC-1α in both testicular tissue and isolated Leydig cells (LCs) were measured. Compared with the ND animals, the WT HFD hamsters developed dyslipidemia at three weeks with lipid droplets deposited in LCs, testosterone decreased at four weeks (0.440 ± 0.264 ng/ml vs. 2.367 ± 1.236 ng/ml), the number of the Sertoli cells decreased (21.578 ± 2.934/one tubule vs. 25.733 ± 3.424/one tubule), the seminiferous epithelium became thinner (0.0813 ± 0.01729 mm vs. 0.0944 ± 0.0138 mm), testicular atrophy and AMPK/Sirt1/PGC-1α pathway downregulated at five weeks. All these changes persisted until the end of the study. LDLR+/- alleviated all of the above changes by downregulating the cellular influx of cholesterol induced by HFD except for higher hyperlipidemia. In summary, excessive intracellular cholesterol inactivates AMPK/Sirt1/PGC-1α pathway firstly in LCs and then in both Sertoli and spermatids. Cholesterol toxicity was LDLR dependent.
Collapse
Affiliation(s)
- Yun Bai
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei, China; Department of Obstetrics and Gynecology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Naiheng Hei
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei, China; The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Mingming Gao
- Laboratory of Lipid Metabolism, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiaohui Dong
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Mingzhao Li
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Shaohao Jiang
- School of Pharmacy, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Lianshan Zhang
- Department of Pathology, Hebei Medical University, Shijiazhuang, Hebei, China.
| |
Collapse
|
4
|
Lenert ME, Burton MD. Sensory neuron LKB1 mediates ovarian and reproductive function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.28.534533. [PMID: 37034663 PMCID: PMC10081243 DOI: 10.1101/2023.03.28.534533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Treatments for reproductive disorders in women primarily consist of hormone replacement therapy, which can have negative health impacts. Bidirectional communication between sensory neurons and innervated organs is an emerging area of interest in tissue physiology with potential relevance for reproductive disorders. Indeed, the metabolic activity of sensory neurons can have profound effects on reproductive phenotypes. To investigate this phenomenon, we utilized a murine model with conditional deletion in sensory neurons of liver kinase B1 (LKB1), a serine/threonine kinase that regulates cellular metabolism. Female mice with this LKB1 deletion (Nav1.8cre;LKB1fl/fl) had significantly more pups per litter compared to wild-type females. Interestingly, the LKB1 genotype of male breeders had no effect on fertility outcomes, thus indicating a female-specific role of sensory neuron metabolism in fertility. LKB1 deletion in sensory neurons resulted in reduced ovarian innervation from dorsal root ganglia neurons and increased follicular turnover compared to littermate controls. In summary, LKB1 expression in peripheral sensory neurons plays an important role in modulating fertility of female mice via ovarian sensory innervation.
Collapse
Affiliation(s)
- Melissa E Lenert
- Neuroimmunology and Behavior Laboratory, Department of Neuroscience, School of Behavioral and Brain Sciences, Center for Advanced Pain Studies (CAPS), The University of Texas at Dallas, Richardson, TX 75080
| | - Michael D Burton
- Neuroimmunology and Behavior Laboratory, Department of Neuroscience, School of Behavioral and Brain Sciences, Center for Advanced Pain Studies (CAPS), The University of Texas at Dallas, Richardson, TX 75080
| |
Collapse
|
5
|
Important Hormones Regulating Lipid Metabolism. Molecules 2022; 27:molecules27207052. [PMID: 36296646 PMCID: PMC9607181 DOI: 10.3390/molecules27207052] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
There is a wide variety of kinds of lipids, and complex structures which determine the diversity and complexity of their functions. With the basic characteristic of water insolubility, lipid molecules are independent of the genetic information composed by genes to proteins, which determine the particularity of lipids in the human body, with water as the basic environment and genes to proteins as the genetic system. In this review, we have summarized the current landscape on hormone regulation of lipid metabolism. After the well-studied PI3K-AKT pathway, insulin affects fat synthesis by controlling the activity and production of various transcription factors. New mechanisms of thyroid hormone regulation are discussed, receptor α and β may mediate different procedures, the effect of thyroid hormone on mitochondria provides a new insight for hormones regulating lipid metabolism. Physiological concentration of adrenaline induces the expression of extrapituitary prolactin in adipose tissue macrophages, which promotes fat weight loss. Manipulation of hormonal action has the potential to offer a new therapeutic horizon for the global burden of obesity and its associated complications such as morbidity and mortality.
Collapse
|
6
|
Bazard P, Pineros J, Acosta AA, Thivierge M, Paganella LR, Zucker S, Mannering FL, Modukuri S, Zhu X, Frisina RD, Ding B. Post-Translational Modifications and Age-related Hearing Loss. Hear Res 2022; 426:108625. [DOI: 10.1016/j.heares.2022.108625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 08/21/2022] [Accepted: 09/23/2022] [Indexed: 11/04/2022]
|
7
|
Garner KM, Burton MD. The sex-specific role of sensory neuron LKB1 on metabolic stress-induced mechanical hypersensitivity and mitochondrial respiration. Am J Physiol Regul Integr Comp Physiol 2022; 323:R227-R243. [PMID: 35503781 PMCID: PMC9306793 DOI: 10.1152/ajpregu.00279.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pain disorders induce metabolic stress in peripheral sensory neurons by reducing mitochondrial output, shifting cellular metabolism, and altering energy use. These processes implicate neuronal metabolism as an avenue for creating novel therapeutics. Liver kinase B1 (LKB1) mediates the cellular response to metabolic stress by inducing the AMPK pathway. The LKB1-AMPK pathway increases energy producing processes, including mitochondrial output. These processes inhibit pain by directly or indirectly restoring energetic balance within a cell. Although the LKB1-AMPK pathway has been linked to pain relief, it is not yet known which cell is responsible for this property, as well any direct ties to cellular metabolism. To elucidate this, we developed a genetic mouse model where LKB1 is selectively removed from Nav1.8-pain sensory neurons and metabolically stressed them by fasting for 24 hours. We found females, but not males, had neuron-specific, LKB1-dependent restoration of metabolic stress-induced mitochondrial metabolism. This was reflected in mechanical hypersensitivity, where the absence of LKB1 led to hypersensitivity in female, but not male, animals. This discrepancy suggests a sex- and cell-specific contribution to LKB1-depdendent fasting-induced mechanical hypersensitivity. While our data represent a potential role for LKB1 in anti-pain pathways in a metabolic-specific manner, more must be done to investigate these sex differences.
Collapse
Affiliation(s)
- Katherine Marie Garner
- Neuroimmunology and Behavior Laboratory, Department of Neuroscience, School of Behavioral and Brain Sciences, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, United States
| | - Michael D Burton
- Neuroimmunology and Behavior Laboratory, Department of Neuroscience, School of Behavioral and Brain Sciences, Center for Advanced Pain Studies, University of Texas at Dallas, Richardson, TX, United States
| |
Collapse
|
8
|
Chen W, Yang H, Yan Q, Zhou X, Tan Z, Wang Z. Effects of maternal feed intake restriction on the blood parameters, fatty acid profile and lipogenetic genes expression of perirenal fat in offspring kids. Anim Reprod Sci 2022; 238:106955. [DOI: 10.1016/j.anireprosci.2022.106955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 02/16/2022] [Accepted: 02/20/2022] [Indexed: 11/17/2022]
|
9
|
Wright RHG, Vastolo V, Oliete JQ, Carbonell-Caballero J, Beato M. Global signalling network analysis of luminal T47D breast cancer cells in response to progesterone. Front Endocrinol (Lausanne) 2022; 13:888802. [PMID: 36034422 PMCID: PMC9403329 DOI: 10.3389/fendo.2022.888802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Breast cancer cells enter into the cell cycle following progestin exposure by the activation of signalling cascades involving a plethora of enzymes, transcription factors and co-factors that transmit the external signal from the cell membrane to chromatin, ultimately leading to a change of the gene expression program. Although many of the events within the signalling network have been described in isolation, how they globally team up to generate the final cell response is unclear. METHODS In this study we used antibody microarrays and phosphoproteomics to reveal a dynamic global signalling map that reveals new key regulated proteins and phosphor-sites and links between previously known and novel pathways. T47D breast cancer cells were used, and phospho-sites and pathways highlighted were validated using specific antibodies and phenotypic assays. Bioinformatic analysis revealed an enrichment in novel signalling pathways, a coordinated response between cellular compartments and protein complexes. RESULTS Detailed analysis of the data revealed intriguing changes in protein complexes involved in nuclear structure, epithelial to mesenchyme transition (EMT), cell adhesion, as well as transcription factors previously not associated with breast cancer cell proliferation. Pathway analysis confirmed the key role of the MAPK signalling cascade following progesterone and additional hormone regulated phospho-sites were identified. Full network analysis shows the activation of new signalling pathways previously not associated with progesterone signalling in T47D breast cancer cells such as ERBB and TRK. As different post-translational modifications can mediate complex crosstalk mechanisms and massive PARylation is also rapidly induced by progestins, we provide details of important chromatin regulatory complexes containing both phosphorylated and PARylated proteins. CONCLUSIONS This study contributes an important resource for the scientific community, as it identifies novel players and connections meaningful for breast cancer cell biology and potentially relevant for cancer management.
Collapse
Affiliation(s)
- Roni H. G. Wright
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
- *Correspondence: Roni H. G. Wright, ; Miguel Beato,
| | - Viviana Vastolo
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Javier Quilez Oliete
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - José Carbonell-Caballero
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Miguel Beato
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- *Correspondence: Roni H. G. Wright, ; Miguel Beato,
| |
Collapse
|
10
|
Inhibition of Scavenger Receptor Class B Type 1 (SR-B1) Expression and Activity as a Potential Novel Target to Disrupt Cholesterol Availability in Castration-Resistant Prostate Cancer. Pharmaceutics 2021; 13:pharmaceutics13091509. [PMID: 34575583 PMCID: PMC8467449 DOI: 10.3390/pharmaceutics13091509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/04/2021] [Accepted: 09/08/2021] [Indexed: 02/07/2023] Open
Abstract
There have been several studies that have linked elevated scavenger receptor class b type 1 (SR-B1) expression and activity to the development and progression of castration-resistant prostate cancer (CRPC). SR-B1 facilitates the influx of cholesterol to the cell from lipoproteins in systemic circulation. This influx of cholesterol may be important for many cellular functions, including the synthesis of androgens. Castration-resistant prostate cancer tumors can synthesize androgens de novo to supplement the loss of exogenous sources often induced by androgen deprivation therapy. Silencing of SR-B1 may impact the ability of prostate cancer cells, particularly those of the castration-resistant state, to maintain the intracellular supply of androgens by removing a supply of cholesterol. SR-B1 expression is elevated in CRPC models and has been linked to poor survival of patients. The overarching belief has been that cholesterol modulation, through either synthesis or uptake inhibition, will impact essential signaling processes, impeding the proliferation of prostate cancer. The reduction in cellular cholesterol availability can impede prostate cancer proliferation through both decreased steroid synthesis and steroid-independent mechanisms, providing a potential therapeutic target for the treatment of prostate cancer. In this article, we discuss and highlight the work on SR-B1 as a potential novel drug target for CRPC management.
Collapse
|
11
|
Hepatic LKB1 Reduces the Progression of Non-Alcoholic Fatty Liver Disease via Genomic Androgen Receptor Signaling. Int J Mol Sci 2021; 22:ijms22157904. [PMID: 34360667 PMCID: PMC8348493 DOI: 10.3390/ijms22157904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/19/2021] [Accepted: 07/21/2021] [Indexed: 02/06/2023] Open
Abstract
The incidence of non-alcoholic fatty liver disease (NAFLD) increases in males aged >45 years, which indicates that androgens are associated with the development and/or progression of NAFLD, although excess dietary intake is the primary causative factor. However, it is uncertain how androgens are involved in the metabolic process of NAFLD, which is associated with the state of steatosis in hepatocytes. To investigate whether androgen receptor (AR) signaling influences NAFLD development, the state of steatosis was monitored in mouse livers and hepatocytes with or without androgens. As a result, hepatic lipid droplets, expression of AR, and phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) increased in the presence of testosterone. Concurrently, the expression of LKB1, an upstream regulator of AMPK, was increased by testosterone treatment. We observed that the fluctuation of AMPK-ACC signaling, which plays an important role in lipogenesis, depends on the presence of testosterone and AR. Additionally, we demonstrated that testosterone bound AR was recruited to the promoter of the LKB1 gene and induced LKB1 expression. Our study highlights a novel mechanism by which testosterone modulates NAFLD development by inducing the mRNA expression of LKB1.
Collapse
|
12
|
Dias IB, Bouma HR, Henning RH. Unraveling the Big Sleep: Molecular Aspects of Stem Cell Dormancy and Hibernation. Front Physiol 2021; 12:624950. [PMID: 33867999 PMCID: PMC8047423 DOI: 10.3389/fphys.2021.624950] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/11/2021] [Indexed: 12/14/2022] Open
Abstract
Tissue-resident stem cells may enter a dormant state, also known as quiescence, which allows them to withstand metabolic stress and unfavorable conditions. Similarly, hibernating mammals can also enter a state of dormancy used to evade hostile circumstances, such as food shortage and low ambient temperatures. In hibernation, the dormant state of the individual and its cells is commonly known as torpor, and is characterized by metabolic suppression in individual cells. Given that both conditions represent cell survival strategies, we here compare the molecular aspects of cellular quiescence, particularly of well-studied hematopoietic stem cells, and torpor at the cellular level. Critical processes of dormancy are reviewed, including the suppression of the cell cycle, changes in metabolic characteristics, and cellular mechanisms of dealing with damage. Key factors shared by hematopoietic stem cell quiescence and torpor include a reversible activation of factors inhibiting the cell cycle, a shift in metabolism from glucose to fatty acid oxidation, downregulation of mitochondrial activity, key changes in hypoxia-inducible factor one alpha (HIF-1α), mTOR, reversible protein phosphorylation and autophagy, and increased radiation resistance. This similarity is remarkable in view of the difference in cell populations, as stem cell quiescence regards proliferating cells, while torpor mainly involves terminally differentiated cells. A future perspective is provided how to advance our understanding of the crucial pathways that allow stem cells and hibernating animals to engage in their 'great slumbers.'
Collapse
Affiliation(s)
- Itamar B. Dias
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Hjalmar R. Bouma
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| |
Collapse
|
13
|
Amin A, Perera ND, Beart PM, Turner BJ, Shabanpoor F. Amyotrophic Lateral Sclerosis and Autophagy: Dysfunction and Therapeutic Targeting. Cells 2020; 9:cells9112413. [PMID: 33158177 PMCID: PMC7694295 DOI: 10.3390/cells9112413] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 02/07/2023] Open
Abstract
Over the past 20 years, there has been a drastically increased understanding of the genetic basis of Amyotrophic Lateral Sclerosis. Despite the identification of more than 40 different ALS-causing mutations, the accumulation of neurotoxic misfolded proteins, inclusions, and aggregates within motor neurons is the main pathological hallmark in all cases of ALS. These protein aggregates are proposed to disrupt cellular processes and ultimately result in neurodegeneration. One of the main reasons implicated in the accumulation of protein aggregates may be defective autophagy, a highly conserved intracellular “clearance” system delivering misfolded proteins, aggregates, and damaged organelles to lysosomes for degradation. Autophagy is one of the primary stress response mechanisms activated in highly sensitive and specialised neurons following insult to ensure their survival. The upregulation of autophagy through pharmacological autophagy-inducing agents has largely been shown to reduce intracellular protein aggregate levels and disease phenotypes in different in vitro and in vivo models of neurodegenerative diseases. In this review, we explore the intriguing interface between ALS and autophagy, provide a most comprehensive summary of autophagy-targeted drugs that have been examined or are being developed as potential treatments for ALS to date, and discuss potential therapeutic strategies for targeting autophagy in ALS.
Collapse
|
14
|
Ayaz G, Razizadeh N, Yaşar P, Kars G, Kahraman DC, Saatci Ö, Şahin Ö, Çetin-Atalay R, Muyan M. CXXC5 as an unmethylated CpG dinucleotide binding protein contributes to estrogen-mediated cellular proliferation. Sci Rep 2020; 10:5971. [PMID: 32249801 PMCID: PMC7136269 DOI: 10.1038/s41598-020-62912-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/17/2020] [Indexed: 02/07/2023] Open
Abstract
Evidence suggests that the CXXC type zinc finger (ZF-CXXC) protein 5 (CXXC5) is a critical regulator/integrator of various signaling pathways that include the estrogen (E2)-estrogen receptor α (ERα). Due to its ZF-CXXC domain, CXXC5 is considered to be a member of the ZF-CXXC family, which binds to unmethylated CpG dinucleotides of DNA and through enzymatic activities for DNA methylation and/or chromatin modifications generates a chromatin state critical for gene expressions. Structural/functional features of CXXC5 remain largely unknown. CXXC5, suggested as transcription and/or epigenetic factor, participates in cellular proliferation, differentiation, and death. To explore the role of CXXC5 in E2-ERα mediated cellular events, we verified by generating a recombinant protein that CXXC5 is indeed an unmethylated CpG binder. We uncovered that CXXC5, although lacks a transcription activation/repression function, participates in E2-driven cellular proliferation by modulating the expression of distinct and mutual genes also regulated by E2. Furthermore, we found that the overexpression of CXXC5, which correlates with mRNA and protein levels of ERα, associates with poor prognosis in ER-positive breast cancer patients. Thus, CXXC5 as an unmethylated CpG binder contributes to E2-mediated gene expressions that result in the regulation of cellular proliferation and may contribute to ER-positive breast cancer progression.
Collapse
Affiliation(s)
- Gamze Ayaz
- Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey.,Cancer and Stem Cell Epigenetics Section, Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Negin Razizadeh
- Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey
| | - Pelin Yaşar
- Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey
| | - Gizem Kars
- Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey
| | - Deniz Cansen Kahraman
- Enformatics Institute, Middle East Technical University, Ankara, 06800, Turkey.,Cansyl Laboratories, Middle East Technical University, Ankara, 06800, Turkey
| | - Özge Saatci
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Özgür Şahin
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA.,Department of Molecular Biology and Genetics, Bilkent University, Ankara, 06800, Turkey
| | - Rengül Çetin-Atalay
- Enformatics Institute, Middle East Technical University, Ankara, 06800, Turkey.,Cansyl Laboratories, Middle East Technical University, Ankara, 06800, Turkey
| | - Mesut Muyan
- Department of Biological Sciences, Middle East Technical University, Ankara, 06800, Turkey. .,Cansyl Laboratories, Middle East Technical University, Ankara, 06800, Turkey.
| |
Collapse
|
15
|
Fazilat A, Rashid N, Nigam A, Anjum S, Gupta N, Wajid S. Differential Expression of MARK4 Protein and Related Perturbations in Females with Ovulatory PCOS. Endocr Metab Immune Disord Drug Targets 2019; 19:1064-1074. [DOI: 10.2174/1871530319666190719145823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/22/2019] [Accepted: 05/16/2019] [Indexed: 12/25/2022]
Abstract
Background:
Ovulatory PCOS (OPCOS) is the mildest form of the polycystic ovarian syndrome
among all four determined phenotypes. Though the females with OPCOS are ovulating, hyperandrogenism
and polycystic ovarian morphology increase the susceptibility of cardiovascular diseases,
insulin resistance, hyperlipidemia and metabolic syndrome in these females.
Objectives:
The aim of the study was to identify the significance associated with OPCOS phenotype
through serum proteomic profiling of OPCOS females and normal age-matched healthy ovulating females.
Methods:
One and two-dimensional gel-based proteomic approaches were adopted to fractionate the
complex serum proteome. Differential protein profiles generated were analyzed with PD-QUEST
Software. Protein spots differing in intensity by >2-fold were selected and identified further by
MALDI-TOF MS. Validation of identified protein was carried out by Biolayer Interferometry.
Results:
One and two-dimensional gel profiles revealed a differential expression pattern of proteins. 10
selected spots were identified as GMP synthase [glutamine hydrolyzing], zinc finger protein 518A,
pericentriolar material 1 protein, BCLAF1 and THRAP3 family member 3, MAP/microtubule affinityregulating
kinase 4, H/ACA ribonucleoprotein complex subunit 1, Melanoma-associated antigen B3
and Zinc finger protein 658B. Expression of MAP/microtubule affinity-regulating kinase 4 (MARK4)
was found to be downregulated in OPCOS females as compared to controls on validation.
Conclusion:
Reduced expression of MARK4 protein in OPCOS increases the associated risk of hyperlipidemia,
hyperandrogenism and metabolic syndrome, thus the protein holds strong candidature as a
drug target for the syndrome.
Collapse
Affiliation(s)
- Ahmad Fazilat
- Department of Biotechnology, School of Chemical and Life Sciences (SCLS), Jamia Hamdard, New Delhi, 110062, India
| | - Nadia Rashid
- Department of Biotechnology, School of Chemical and Life Sciences (SCLS), Jamia Hamdard, New Delhi, 110062, India
| | - Aruna Nigam
- Department of Gynaecology and Obstetrics, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Shadab Anjum
- Department of Biotechnology, School of Chemical and Life Sciences (SCLS), Jamia Hamdard, New Delhi, 110062, India
| | - Nimisha Gupta
- Department of Biotechnology, School of Chemical and Life Sciences (SCLS), Jamia Hamdard, New Delhi, 110062, India
| | - Saima Wajid
- Department of Biotechnology, School of Chemical and Life Sciences (SCLS), Jamia Hamdard, New Delhi, 110062, India
| |
Collapse
|
16
|
Gibb FW, Dixon JM, Clarke C, Homer NZ, Faqehi AMM, Andrew R, Walker BR. Higher Insulin Resistance and Adiposity in Postmenopausal Women With Breast Cancer Treated With Aromatase Inhibitors. J Clin Endocrinol Metab 2019; 104:3670-3678. [PMID: 30920624 PMCID: PMC6642666 DOI: 10.1210/jc.2018-02339] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/22/2019] [Indexed: 01/25/2023]
Abstract
CONTEXT Aromatase deficiency causes obesity and insulin resistance in aromatase knockout mice and humans with rare mutations of the aromatase gene (CYP19). Aromatase inhibitors are a commonly prescribed therapy for postmenopausal breast cancer. OBJECTIVE We hypothesized that aromatase inhibitors induce obesity and insulin resistance when used in treatment of breast cancer. DESIGN Case-control study. SETTING University teaching hospital. PARTICIPANTS Patients with postmenopausal breast cancer (n = 20) treated with aromatase inhibitors and 20 age-matched control subjects. MAIN OUTCOME MEASURES The primary outcome measure was insulin sensitivity index - Matsuda, derived from a 75-g oral glucose tolerance test. Body composition was assessed by dual energy x-ray absorptiometry and biopsy specimens of subcutaneous adipose tissue obtained for assessment of mRNA transcript levels. Data are reported as mean ± SEM (patients receiving inhibitors vs control group, respectively). RESULTS Aromatase inhibitor therapy was associated with significantly lower insulin sensitivity (5.15 ± 0.45 vs 6.80 ± 0.64; P = 0.041), higher peak insulin concentration after oral glucose tolerance test (693.4 ± 78.6 vs 527.6 ± 85.5 pmol/L; P = 0.035), greater percentage of body fat (38.4% ± 1.0% vs 34.6% ± 1.3%; P = 0.026), and higher plasma leptin concentration (23.5 ± 2.8 vs 15.5 ± 2.3 ng/mL; P = 0.035). CONCLUSION Women who received aromatase inhibitors for postmenopausal breast cancer had greater percentage body fat and insulin resistance compared with control subjects with no history of breast cancer.
Collapse
Affiliation(s)
- Fraser W Gibb
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
- Correspondence and Reprint Requests: Fraser W. Gibb PhD, FRCP, Edinburgh Centre for Endocrinology and Diabetes, Royal Infirmary of Edinburgh, Edinburgh EH16 6AG, United Kingdom. E-mail:
| | - J Michael Dixon
- Edinburgh Breast Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Catriona Clarke
- Clinical Biochemistry, Western General Hospital, Edinburgh, United Kingdom
| | - Natalie Z Homer
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Abdullah M M Faqehi
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Ruth Andrew
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Brian R Walker
- British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
- Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom
| |
Collapse
|
17
|
Mak TCS, Livingstone DEW, Nixon M, Walker BR, Andrew R. Role of Hepatic Glucocorticoid Receptor in Metabolism in Models of 5αR1 Deficiency in Male Mice. Endocrinology 2019; 160:2061-2073. [PMID: 31199473 PMCID: PMC6735737 DOI: 10.1210/en.2019-00236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/10/2019] [Indexed: 02/08/2023]
Abstract
Inhibition of 5α-reductases impairs androgen and glucocorticoid metabolism and induces insulin resistance in humans and rodents. The contribution of hepatic glucocorticoids to these adverse metabolic changes was assessed using a liver-selective glucocorticoid receptor (GR) antagonist, A-348441. Mice lacking 5α-reductase 1 (5αR1-KO) and their littermate controls were studied during consumption of a high-fat diet, with or without A-348441(120 mg/kg/d). Male C57BL/6 mice (age, 12 weeks) receiving dutasteride (1.8 mg/kg/d)) or vehicle with consumption of a high-fat diet, with or without A-348441, were also studied. In the 5αR1-KO mice, hepatic GR antagonism improved diet-induced insulin resistance but not more than that of the controls. Liver steatosis was not affected by hepatic GR antagonism in either 5αR1KO mice or littermate controls. In a second model of 5α-reductase inhibition using dutasteride and hepatic GR antagonism with A-348441 attenuated the excess weight gain resulting from dutasteride (mean ± SEM, 7.03 ± 0.5 vs 2.13 ± 0.4 g; dutasteride vs dutasteride plus A-348441; P < 0.05) and normalized the associated hyperinsulinemia after glucose challenge (area under the curve, 235.9 ± 17 vs 329.3 ± 16 vs 198.4 ± 25 ng/mL/min; high fat vs high fat plus dutasteride vs high fat plus dutasteride plus A-348441, respectively; P < 0.05). However, A-348441 again did not reverse dutasteride-induced liver steatosis. Thus, overall hepatic GR antagonism improved the insulin resistance but not the steatosis induced by a high-fat diet. Moreover, it attenuated the excessive insulin resistance caused by pharmacological inhibition of 5α-reductases but not genetic disruption of 5αR1. The use of dutasteride might increase the risk of type 2 diabetes mellitus and reduced exposure to glucocorticoids might be beneficial.
Collapse
Affiliation(s)
- Tracy C S Mak
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Dawn E W Livingstone
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark Nixon
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Brian R Walker
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Ruth Andrew
- University/British Heart Foundation Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
18
|
Xu YXZ, Ande SR, Mishra S. Gonadectomy in Mito-Ob mice revealed a sex-dimorphic relationship between prohibitin and sex steroids in adipose tissue biology and glucose homeostasis. Biol Sex Differ 2018; 9:37. [PMID: 30157935 PMCID: PMC6114179 DOI: 10.1186/s13293-018-0196-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/15/2018] [Indexed: 01/11/2023] Open
Abstract
Background Recently, we have developed a novel transgenic mouse model by overexpressing prohibitin (PHB) in adipocytes, which developed obesity due to upregulation of mitochondrial biogenesis in adipocytes, hence named “Mito-Ob.” Interestingly, only male Mito-Ob mice developed obesity-related impaired glucose homeostasis and insulin sensitivity, whereas female Mito-Ob mice did not. The observed sex differences in metabolic dysregulation suggest a potential involvement of sex steroids. Thus, the main aim of this study is to investigate the role of sex steroids on the overall phenotype of Mito-Ob mice through gonadectomy, as well as direct effect of sex steroids on adipocytes from Mito-Ob mice in vitro. Methods Mito-Ob mice and wild-type CD-1 mice were gonadectomized at 12 weeks of age. Age- and sex-matched sham-operated mice were used as controls. Body weight, white adipose tissue, glucose tolerance, and insulin sensitivity were analyzed 3 months post-surgery. Differentiation of adipocytes isolated from female and male Mito-Ob mice were studied with and without sex steroids. Results Gonadectomy significantly reduced body weight in Mito-Ob mice compared with sham-operated mice, whereas the opposite trend was observed in wild-type mice. These changes occurred independent of food intake. A corresponding decrease in adipose tissue weight was found in gonadectomized Mito-Ob mice, but depot-specific differences were observed in male and female. Gonadectomy improved glucose tolerance in male wild-type and Mito-Ob mice, but the effect was more pronounced in wild-type mice. Gonadectomy did not alter insulin sensitivity in male Mito-Ob mice, but it was improved in male wild-type mice. In primary cell cultures, testosterone inhibited adipocyte differentiation to a lesser extent in male Mito-Ob preadipocytes compared with the wild-type mice. On the other hand, preadipocytes from female wild-type mice showed better differentiation potential than those from female Mito-Ob mice in the presence of 17β-estradiol. Conclusions PHB requires sex steroids for the development of obese phenotype in Mito-Ob mice, which differentially affect glucose homeostasis and insulin sensitivity in male and female. It appears that PHB plays sex- and adipose depot-specific roles and involves additional factors. In vitro studies suggested that PHB differently influenced adipocyte differentiation in the presence and absence of sex steroids. Overall, this study along with available information in the literature indicated that a multifaceted relationship exists between PHB and sex steroids, which may work in a cell/tissue type- and sex-specific manner.
Collapse
Affiliation(s)
- Yang Xin Zi Xu
- Department of Physiology and Pathophysiology, Faculty of Health Sciences, University of Manitoba, Rm. 843 JBRC/715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada
| | - Sudharsana Rao Ande
- Department of Internal Medicine, Faculty of Health Sciences, University of Manitoba, Rm. 843 JBRC/715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada
| | - Suresh Mishra
- Department of Physiology and Pathophysiology, Faculty of Health Sciences, University of Manitoba, Rm. 843 JBRC/715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada. .,Department of Internal Medicine, Faculty of Health Sciences, University of Manitoba, Rm. 843 JBRC/715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada.
| |
Collapse
|
19
|
Hu MT, Wang JH, Yu Y, Liu C, Li B, Cheng QB, Jiang XQ. Tumor suppressor LKB1 inhibits the progression of gallbladder carcinoma and predicts the prognosis of patients with this malignancy. Int J Oncol 2018; 53:1215-1226. [PMID: 30015925 DOI: 10.3892/ijo.2018.4466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/02/2018] [Indexed: 01/17/2023] Open
Abstract
Gallbladder carcinoma (GBC) represents the most common fatal tumors of the biliary tract. The 3-year or 5-year survival rate for patients with this disease are 30 and 5%, respectively. Liver kinase B1 (LKB1), a primary upstream kinase of adenosine monophosphate-activated protein kinase (AMPK) necessary for maintaining cell metabolism and energy homeostasis, has been found to be an important tumor suppressor gene in recent years, and its inactivation has also found to be closely associated with tumor growth, metastasis and cancer stem cell (CSC) proliferation. Nevertheless, the function of LKB1 in GBC remains unclear. In this study, we found that the expression of LKB1 in GBC tissues was decreased compared with that in non-cancerous tissues. LKB1 overexpression suppressed the proliferation, metastasis and expansion of GBC CSCs. Mechanically, LKB1 suppressed GBC cell progression via the JAK/signal transducer and activator of transcription 3 (STAT3) pathway. The use of the JAK2 inhibitor, AZD‑1480, attenuated the suppressive effects of LKB1 overexpression on the growth, metastasis and self-renewal ability of the GBC cells, which further demonstrated that JAK/STAT3 was involved in the LKB1-induced suppression of GBC cell growth, metastasis and self-renewal ability. More importantly, the decreased expression of LKB1 was a predictor of a poor prognosis of patients with GBC. On the whole, our data indicate that LKB1 inhibits GBC cell growth, metastasis and self-renewal ability by disrupting JAK/STAT3 signaling, and may thus prove to be a novel prognostic biomarker for patients with GBC.
Collapse
Affiliation(s)
- Ming-Tai Hu
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| | - Jing-Han Wang
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| | - Yong Yu
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| | - Chen Liu
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| | - Bin Li
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| | - Qing-Bao Cheng
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| | - Xiao-Qing Jiang
- First Department of Biliary Surgery, Third Affiliated Hospital of PLA Second Military Medical University, Shanghai 200438, P.R. China
| |
Collapse
|
20
|
Asih PR, Tegg ML, Sohrabi H, Carruthers M, Gandy SE, Saad F, Verdile G, Ittner LM, Martins RN. Multiple Mechanisms Linking Type 2 Diabetes and Alzheimer's Disease: Testosterone as a Modifier. J Alzheimers Dis 2018; 59:445-466. [PMID: 28655134 DOI: 10.3233/jad-161259] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Evidence in support of links between type-2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) has increased considerably in recent years. AD pathological hallmarks include the accumulation of extracellular amyloid-β (Aβ) and intracellular hyperphosphorylated tau in the brain, which are hypothesized to promote inflammation, oxidative stress, and neuronal loss. T2DM exhibits many AD pathological features, including reduced brain insulin uptake, lipid dysregulation, inflammation, oxidative stress, and depression; T2DM has also been shown to increase AD risk, and with increasing age, the prevalence of both conditions increases. In addition, amylin deposition in the pancreas is more common in AD than in normal aging, and although there is no significant increase in cerebral Aβ deposition in T2DM, the extent of Aβ accumulation in AD correlates with T2DM duration. Given these similarities and correlations, there may be common underlying mechanism(s) that predispose to both T2DM and AD. In other studies, an age-related gradual loss of testosterone and an increase in testosterone resistance has been shown in men; low testosterone levels can also occur in women. In this review, we focus on the evidence for low testosterone levels contributing to an increased risk of T2DM and AD, and the potential of testosterone treatment in reducing this risk in both men and women. However, such testosterone treatment may need to be long-term, and would need regular monitoring to maintain testosterone at physiological levels. It is possible that a combination of testosterone therapy together with a healthy lifestyle approach, including improved diet and exercise, may significantly reduce AD risk.
Collapse
Affiliation(s)
- Prita R Asih
- Department of Anatomy, Dementia Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,KaRa Institute of Neurological Diseases, Sydney, NSW, Australia
| | - Michelle L Tegg
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia
| | - Hamid Sohrabi
- School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia.,Australian Alzheimer's Research Foundation Perth, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
| | | | - Samuel E Gandy
- Departments of Neurology and Psychiatry and the Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, One Gustave L Levy Place, New York, NY, USA
| | - Farid Saad
- Bayer Pharma AG, Global Medical Affairs Andrology, Berlin, Germany.,Gulf Medical University School of Medicine, Ajman, UAE
| | - Giuseppe Verdile
- Australian Alzheimer's Research Foundation Perth, WA, Australia.,School of Biomedical Sciences, Curtin University of Technology, Bentley, WA, Australia
| | - Lars M Ittner
- Department of Anatomy, Dementia Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuroscience Research Australia, Sydney, NSW, Australia
| | - Ralph N Martins
- KaRa Institute of Neurological Diseases, Sydney, NSW, Australia.,School of Medical and Health Sciences, Edith Cowan University, Perth, WA, Australia.,Australian Alzheimer's Research Foundation Perth, WA, Australia.,Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, WA, Australia
| |
Collapse
|
21
|
Huang Y, Ratz PH, Miner AS, Locke VA, Chen G, Chen Y, Barbee RW. AICAR Administration Attenuates Hemorrhagic Hyperglycemia and Lowers Oxygen Debt in Anesthetized Male Rabbits. Front Physiol 2017; 8:692. [PMID: 28955248 PMCID: PMC5601404 DOI: 10.3389/fphys.2017.00692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/29/2017] [Indexed: 01/05/2023] Open
Abstract
Background: Many strategies have been utilized to treat traumatic shock via improved oxygen delivery (DO2), while fewer have been used to in an attempt to reduce oxygen demand (VO2). The cellular energy sensor 5′ adenosine monophosphate-activated protein kinase (AMPK) has the potential to modulate both whole-body DO2 and VO2. Therefore, we determined the effect of the AMPK activator AICAR (5-aminoimidazole-4-carboxamide 1-β-D-ribonucleoside) given acutely or chronically on key metabolites, hemodynamics, and oxygen consumption/delivery before and during hemorrhage in anesthetized male rabbits. Methods: Chronically treated animals received AICAR (40 mg/kg/day, IV) for 10 days prior to hemorrhage, while rabbits in the acute study were infused with AICAR (7.5 mg/kg bolus, 2 mg/kg/min infusion) or vehicle (0.3 ml/kg saline bolus, 0.03 ml/kg/min infusion) IV for 2 h prior to severe hemorrhage. Both acutely and chronically treated animals were sedated (ketamine/xylazine cocktail) the morning of the terminal experiment and surgically prepared for hemorrhage, including the implantation of arterial and venous catheters (for blood removal/sampling and drug/vehicle administration) and thoracotomy for implantation of transit-time flow transducers (for cardiac output determination). Results: AICAR given acutely lowered arterial blood glucose and increased blood lactate levels before hemorrhage, and abolished the well-documented hemorrhage-induced hyperglycemia seen in vehicle treated animals. Animals given AICAR chronically had blunted hemorrhage-induced hyperglycemia without prior baseline changes. Chronically treated AICAR animals showed significantly lower lactate levels during hemorrhage. Rabbits receiving AICAR both acutely and chronically experienced similar falls in mean arterial pressure, cardiac output and hence DO2 to their vehicle counterparts throughout the hemorrhage period. However, rabbits treated either acutely or chronically with AICAR accumulated lower oxygen deficits and debt during hemorrhage compared to vehicle-infused controls. Conclusions: The oxygen debt data suggest that AMPK activation could decrease trauma associated morbidity and mortality, perhaps by mechanisms related to increased glucose utilization. Additional studies are needed to investigate the effects of AICAR and associated mechanisms of action when given during resuscitation from hemorrhage.
Collapse
Affiliation(s)
- Yi Huang
- Department of Emergency Medicine, Virginia Commonwealth UniversityRichmond, VA, United States.,Medical Center of Stomatology, The First Affiliated Hospital of Jinan UniversityGuangzhou, China
| | - Paul H Ratz
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth UniversityRichmond, VA, United States.,Department of Pediatrics, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Amy S Miner
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Victoria A Locke
- Department of Emergency Medicine, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Grace Chen
- Department of Emergency Medicine, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Yang Chen
- Department of Pharmacology and Toxicology, Virginia Commonwealth UniversityRichmond, VA, United States
| | - Robert W Barbee
- Department of Emergency Medicine, Virginia Commonwealth UniversityRichmond, VA, United States.,Department of Physiology and Biophysics, Virginia Commonwealth UniversityRichmond, VA, United States
| |
Collapse
|
22
|
Khan AS, Frigo DE. A spatiotemporal hypothesis for the regulation, role, and targeting of AMPK in prostate cancer. Nat Rev Urol 2017; 14:164-180. [PMID: 28169991 PMCID: PMC5672799 DOI: 10.1038/nrurol.2016.272] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The 5'-AMP-activated protein kinase (AMPK) is a master regulator of cellular homeostasis. Despite AMPK's known function in physiology, its role in pathological processes such as prostate cancer is enigmatic. However, emerging evidence is now beginning to decode the paradoxical role of AMPK in cancer and, therefore, inform clinicians if - and how - AMPK could be therapeutically targeted. Spatiotemporal regulation of AMPK complexes could be one of the mechanisms that governs this kinase's role in cancer. We hypothesize that different upstream stimuli will activate select subcellular AMPK complexes. This hypothesis is supported by the distinct subcellular locations of the various AMPK subunits. Each of these unique AMPK complexes regulates discrete downstream processes that can be tumour suppressive or oncogenic. AMPK's final biological output is then determined by the weighted net function of these downstream signalling events, influenced by additional prostate-specific signalling.
Collapse
Affiliation(s)
- Ayesha S. Khan
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX USA
| | - Daniel E. Frigo
- Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX USA
- Genomic Medicine Program, The Houston Methodist Research Institute, Houston, TX USA
| |
Collapse
|
23
|
Kim SA, Lee KY, Kim JR, Choi HC. Estrogenic compound attenuates angiotensin II-induced vascular smooth muscle cell proliferation through interaction between LKB1 and estrogen receptor α. J Pharmacol Sci 2016; 132:78-85. [PMID: 27665370 DOI: 10.1016/j.jphs.2016.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/04/2016] [Accepted: 08/29/2016] [Indexed: 12/29/2022] Open
Abstract
The prevalence rate of cardiovascular disease is higher for males than females, and estradiol (E2) induces AMP-activated protein kinase (AMPK) activation, which is known to regulate proliferation of VSMC. We identified the estrogenic properties of nordihydroguaiaretic acid (NDGA, a lignan phytoestrogen) that inhibit VSMC proliferation and explored the underlying mechanisms. Both the phosphorylation and expression of LKB1 were increased by NDGA. In addition, NDGA significantly attenuated angiotensin II (Ang II)-induced VSMC proliferation. To elucidate the estrogenic effects, we confirmed that NDGA increased estrogen receptor α (ERα) expression, similar to treatment with E2 and estriol (E3). Furthermore, tamoxifen and ERα siRNA obstructed the effects of NDGA including ERα expression, AMPK phosphorylation and both LKB1 phosphorylation and expression. VSMC proliferation was restored by tamoxifen and ERα siRNA. LKB1 siRNA also reversed the NDGA-mediated inhibition of VSMC proliferation. The estrogenic activity of NDGA induced LKB1 translocation from nucleus to cytosol, and tamoxifen obstructed LKB1 translocation. The absence of LKB1 completely abolished the increase of ERα expression induced by NDGA. Taken together, the beneficial effects of estrogenic compound (E2 and NDGA) on inhibition of VSMC proliferation are mediated by interaction between LKB1 and ERα, suggesting a potential mechanism for females having less cardiovascular disease.
Collapse
Affiliation(s)
- Sun Ae Kim
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea
| | - Kyung Young Lee
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea; Smart-aging Convergence Research Center, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea
| | - Jae-Ryong Kim
- Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea; Smart-aging Convergence Research Center, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea
| | - Hyoung Chul Choi
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea; Smart-aging Convergence Research Center, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu, 42415, Republic of Korea.
| |
Collapse
|
24
|
Mitsuhashi K, Senmaru T, Fukuda T, Yamazaki M, Shinomiya K, Ueno M, Kinoshita S, Kitawaki J, Katsuyama M, Tsujikawa M, Obayashi H, Nakamura N, Fukui M. Testosterone stimulates glucose uptake and GLUT4 translocation through LKB1/AMPK signaling in 3T3-L1 adipocytes. Endocrine 2016; 51:174-84. [PMID: 26100787 DOI: 10.1007/s12020-015-0666-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
Abstract
Decreases in serum testosterone concentrations in aging men are associated with metabolic disorders. Testosterone has been reported to increase GLUT4-dependent glucose uptake in skeletal muscle cells and cardiomyocytes. However, studies on glucose uptake occurring in response to testosterone stimulation in adipocytes are currently not available. This study was designed to determine the effects of testosterone on glucose uptake in adipocytes. Glucose uptake was assessed with 2-[(3)H] deoxyglucose in 3T3-L1 adipocytes. GLUT4 translocation was evaluated in plasma membrane (PM) sheets and PM fractions by immunofluorescence and immunoblotting, respectively. Activation of GLUT4 translocation-related protein kinases, including Akt, AMPK, LKB1, CaMKI, CaMKII, and Cbl was followed by immunoblotting. Expression levels of androgen receptor (AR) mRNA and AR translocation to the PM were assessed by real-time RT-PCR and immunoblotting, respectively. The results showed that both high-dose (100 nM) testosterone and testosterone-BSA increased glucose uptake and GLUT4 translocation to the PM, independently of the intracellular AR. Testosterone and testosterone-BSA stimulated the phosphorylation of AMPK, LKB1, and CaMKII. The knockdown of LKB1 by siRNA attenuated testosterone- and testosterone-BSA-stimulated AMPK phosphorylation and glucose uptake. These results indicate that high-dose testosterone and testosterone-BSA increase GLUT4-dependent glucose uptake in 3T3-L1 adipocytes by inducing the LKB1/AMPK signaling pathway.
Collapse
Affiliation(s)
- Kazuteru Mitsuhashi
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Takafumi Senmaru
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan.
| | - Takuya Fukuda
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Masahiro Yamazaki
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Katsuhiko Shinomiya
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
| | - Morio Ueno
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
| | - Shigeru Kinoshita
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
| | - Jo Kitawaki
- Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan
| | - Masato Katsuyama
- Radioisotope Center, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | | | | | - Naoto Nakamura
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Michiaki Fukui
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan
| |
Collapse
|
25
|
Novikova DS, Garabadzhiu AV, Melino G, Barlev NA, Tribulovich VG. AMP-activated protein kinase: structure, function, and role in pathological processes. BIOCHEMISTRY (MOSCOW) 2015; 80:127-44. [PMID: 25756529 DOI: 10.1134/s0006297915020017] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recently, AMP-activated protein kinase (AMPK) has emerged as a key regulator of energy balance at cellular and whole-body levels. Due to the involvement in multiple signaling pathways, AMPK efficiently controls ATP-consuming/ATP-generating processes to maintain energy homeostasis under stress conditions. Loss of the kinase activity or attenuation of its expression leads to a variety of metabolic disorders and increases cancer risk. In this review, we discuss recent findings on the structure of AMPK, its activation mechanisms, as well as the consequences of its targets in regulation of metabolism. Particular attention is given to low-molecular-weight compounds that activate or inhibit AMPK; the perspective of therapeutic use of such modulators in treatment of several common diseases is discussed.
Collapse
Affiliation(s)
- D S Novikova
- Saint Petersburg State Technological Institute (Technical University), St. Petersburg, 190013, Russia.
| | | | | | | | | |
Collapse
|
26
|
Kim J, Lee YH, Park JHY, Sung MK. Estrogen deprivation and excess energy supply accelerate 7,12-dimethylbenz(a)anthracene-induced mammary tumor growth in C3H/HeN mice. Nutr Res Pract 2015; 9:628-36. [PMID: 26634052 PMCID: PMC4667204 DOI: 10.4162/nrp.2015.9.6.628] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/18/2015] [Accepted: 06/17/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND/OBJECTIVES Obesity is a risk factor of breast cancer in postmenopausal women. Estrogen deprivation has been suggested to cause alteration of lipid metabolism thereby creating a cellular microenvironment favoring tumor growth. The aim of this study is to investigate the effects of estrogen depletion in combination with excess energy supply on breast tumor development. MATERIALS/METHODS Ovariectomized (OVX) or sham-operated C3H/HeN mice at 4 wks were provided with either a normal diet or a high-fat diet (HD) for 16 weeks. Breast tumors were induced by administration of 7,12-dimethylbenz(a)anthracene once a week for six consecutive weeks. RESULTS Study results showed higher serum concentrations of free fatty acids and insulin in the OVX+HD group compared to other groups. The average tumor volume was significantly larger in OVX+HD animals than in other groups. Expressions of mammary tumor insulin receptor and mammalian target of rapamycin proteins as well as the ratio of pAKT/AKT were significantly increased, while pAMPK/AMPK was decreased in OVX+HD animals compared to the sham-operated groups. Higher relative expression of liver fatty acid synthase mRNA was observed in OVX+HD mice compared with other groups. CONCLUSIONS These results suggest that excess energy supply affects the accelerated mammary tumor growth in estrogen deprived mice.
Collapse
Affiliation(s)
- Jin Kim
- Department of Food and Nutrition, Sookmyung Women's University, 100 Chungpa-ro 47-gil, Yongsan-gu, Seoul, 140-742, Korea
| | - Yoon Hee Lee
- Department of Food and Nutrition, Sookmyung Women's University, 100 Chungpa-ro 47-gil, Yongsan-gu, Seoul, 140-742, Korea
| | - Jung Han Yoon Park
- Department of Food Science and Nutrition, College of Natural Sciences, Hallym University, 39 Hallymdaehak-gil, Chuncheon, 200-702, Korea
| | - Mi-Kyung Sung
- Department of Food and Nutrition, Sookmyung Women's University, 100 Chungpa-ro 47-gil, Yongsan-gu, Seoul, 140-742, Korea
| |
Collapse
|
27
|
Oestrogen receptors interact with the α-catalytic subunit of AMP-activated protein kinase. Biosci Rep 2015; 35:BSR20150074. [PMID: 26374855 PMCID: PMC4626870 DOI: 10.1042/bsr20150074] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 09/10/2015] [Indexed: 01/19/2023] Open
Abstract
We identified a novel interaction between the classical oestrogen receptors (ERα and ERβ) and the catalytic subunit of AMP-activated protein kinase (AMPK) in several cell types. In addition, we demonstrate that oestradiol (E2) activates AMPK through ERα and requires the upstream kinase complex liver kinase B (LKB1). Normal and pathological stressors engage the AMP-activated protein kinase (AMPK) signalling axis to protect the cell from energetic pressures. Sex steroid hormones also play a critical role in energy metabolism and significantly modify pathological progression of cardiac disease, diabetes/obesity and cancer. AMPK is targeted by 17β-oestradiol (E2), the main circulating oestrogen, but the mechanism by which E2 activates AMPK is currently unknown. Using an oestrogen receptor α/β (ERα/β) positive (T47D) breast cancer cell line, we validated E2-dependent activation of AMPK that was mediated through ERα (not ERβ) by using three experimental strategies. A series of co-immunoprecipitation experiments showed that both ERs associated with AMPK in cancer and striated (skeletal and cardiac) muscle cells. We further demonstrated direct binding of ERs to the α-catalytic subunit of AMPK within the βγ-subunit-binding domain. Finally, both ERs interacted with the upstream liver kinase B 1 (LKB1) kinase complex, which is required for E2-dependent activation of AMPK. We conclude that E2 activates AMPK through ERα by direct interaction with the βγ-binding domain of AMPKα.
Collapse
|
28
|
Liu Z, Dai X, Zhu H, Zhang M, Zou MH. Lipopolysaccharides Promote S-Nitrosylation and Proteasomal Degradation of Liver Kinase B1 (LKB1) in Macrophages in Vivo. J Biol Chem 2015; 290:19011-7. [PMID: 26070564 PMCID: PMC4521026 DOI: 10.1074/jbc.m115.649210] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/11/2015] [Indexed: 01/28/2023] Open
Abstract
LKB1 (liver kinase B1) plays important roles in tumor suppression, energy metabolism, and, recently, in innate immune responses. However, how LKB1 is regulated under physiological or pathological conditions is still unclear. Here, we report that LKB1 protein (but not mRNA) was decreased in both LPS-treated RAW 264.7 cells and peritoneal macrophages isolated from LPS-challenged mice. Additional LPS treatment promoted protein ubiquitination and degradation of LKB1. Pharmacological inhibition or gene silencing of inducible NOS abrogated LPS-induced LKB1 degradation, whereas exposure of RAW 264.7 cells to S-nitroso-l-glutathione, a NO donor, triggered LKB1 S-nitrosylation. Consistently, mutation of one cysteine (C430S) in LKB1 prevented LPS-induced S-nitrosylation, ubiquitination, and degradation. Moreover, S-nitrosylation and ubiquitination of LKB1 were confirmed in macrophages from LPS-challenged mice in vivo. Co-administration of the inducible NOS inhibitor S-methylisothiourea or the proteasome inhibitor MG132 prevented LPS-induced LKB1 degradation and improved the survival rate. Finally, mice lacking LKB1 in macrophages had significantly lower survival rates in response to LPS challenge compared with wild-type mice. Thus, we concluded that LKB1 is degraded by LPS treatment via S-nitrosylation-dependent proteasome pathways, and this had a protective role in LPS-induced septic shock.
Collapse
Affiliation(s)
- Zhaoyu Liu
- From the Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Xiaoyan Dai
- From the Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Huaiping Zhu
- From the Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Miao Zhang
- From the Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Ming-Hui Zou
- From the Section of Molecular Medicine, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| |
Collapse
|
29
|
Mao KS, Li MS, Zhou J. Update on the roles of liver kinase B1 in pancreatic cancer. Shijie Huaren Xiaohua Zazhi 2015; 23:3086-3093. [DOI: 10.11569/wcjd.v23.i19.3086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Germline mutations of the liver kinase B1 (STK11/LKB1) gene which encodes a serine/threonine kinase is responsible for Peutz-Jeghers syndrome. There are 14 AMP-activated protein kinase (AMPK)-related kinases in pathways downstream of LKB1, which are involved in many physiological and pathological processes such as regulation of energy metabolism, cell polarity and apoptosis in cells. LKB1 gene mutation has been investigated extensively in a variety of cancers, including pancreatic cancer. Pancreatic cancer is commonly recognized as a disease with extremely poor prognosis. Therefore, a full understanding of its molecular pathology is critical. This review aims to elucidate the structure, distribution, and function of LKB1, and the relationship with pancreatic cancer. In addition, we also point out that in some scenarios, LKB1 may play a role as a tumor protector.
Collapse
|
30
|
Popovics P, Frigo DE, Schally AV, Rick FG. Targeting the 5'-AMP-activated protein kinase and related metabolic pathways for the treatment of prostate cancer. Expert Opin Ther Targets 2015; 19:617-32. [PMID: 25600663 DOI: 10.1517/14728222.2015.1005603] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Increasing evidence suggests that prostate cancer cells undergo unique metabolic reprogramming during transformation. A master regulator of cellular homeostasis, 5'-AMP-activated protein kinase (AMPK), directs metabolic adaptation that supports the growth demands of rapidly dividing cancer cells. The utilization of AMPK as a therapeutic target may therefore provide an effective strategy in the treatment of prostate cancer. AREAS COVERED Our review describes the regulation of AMPK by androgens and upstream kinases including the calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) in prostate cancer. Oncogenic, AMPK-regulated pathways that direct various metabolic processes are also addressed. Furthermore, we discuss the role of AMPK in growth arrest and autophagy as a potential survival pathway for cancer cells. In addition, by regulating non-metabolic pathways, AMPK may stimulate migration and mitosis. Finally, this review summarizes efforts to treat prostate cancer with pharmacological agents capable of modulating AMPK signaling. EXPERT OPINION Current research is primarily focused on developing drugs that activate AMPK as a treatment for prostate cancer. However, oncogenic aspects of AMPK signaling calls for caution about employing such therapies. We think that inhibitors of CaMKK2 or AMPK, or perhaps the modulation of downstream targets of AMPK, will gain importance in the clinical management of prostate cancer.
Collapse
Affiliation(s)
- Petra Popovics
- Veterans Affairs Medical Center and South Florida Veterans Affairs Foundation for Research and Education , Research (151) 2A127, 1201 NW 16th St, Miami, FL 33125 , USA +1 305 5753477 ; +1 305 5753126 ;
| | | | | | | |
Collapse
|
31
|
Recent progress on liver kinase B1 (LKB1): expression, regulation, downstream signaling and cancer suppressive function. Int J Mol Sci 2014; 15:16698-718. [PMID: 25244018 PMCID: PMC4200829 DOI: 10.3390/ijms150916698] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/12/2014] [Accepted: 08/28/2014] [Indexed: 12/15/2022] Open
Abstract
Liver kinase B1 (LKB1), known as a serine/threonine kinase, has been identified as a critical cancer suppressor in many cancer cells. It is a master upstream kinase of 13 AMP-activated protein kinase (AMPK)-related protein kinases, and possesses versatile biological functions. LKB1 gene is mutated in many cancers, and its protein can form different protein complexes with different cellular localizations in various cell types. The expression of LKB1 can be regulated through epigenetic modification, transcriptional regulation and post-translational modification. LKB1 dowcnstream pathways mainly include AMPK, microtubule affinity regulating kinase (MARK), salt-inducible kinase (SIK), sucrose non-fermenting protein-related kinase (SNRK) and brain selective kinase (BRSK) signalings, etc. This review, therefore, mainly discusses recent studies about the expression, regulation, downstream signaling and cancer suppressive function of LKB1, which can be helpful for better understanding of this molecular and its significance in cancers.
Collapse
|
32
|
Ibáñez L, Ong KK, López-Bermejo A, Dunger DB, de Zegher F. Hyperinsulinaemic androgen excess in adolescent girls. Nat Rev Endocrinol 2014; 10:499-508. [PMID: 24776733 DOI: 10.1038/nrendo.2014.58] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hyperinsulinaemic androgen excess is the most common cause of hirsutism, acne and menstrual irregularity in adolescent girls. Here, we propose that the disorder frequently originates from an absolute or relative excess of lipids in adipose tissue, and from associated changes in insulin sensitivity, gonadotropin secretion and ovarian androgen release. Girls from populations with genotypes attuned to nutritionally harsh conditions seem to be particularly vulnerable to the development of hyperinsulinaemic androgen excess in today's obesogenic environment. We propose that hirsutism, hyperandrogenaemia and menstrual irregularity (≥2 years after menarche) is used as a diagnostic triad for the disorder. No pharmacological therapy has been approved for girls with androgen excess; however, lifestyle intervention is essential to reduce adiposity. In girls without obesity who are not sexually active, insulin sensitization has more broadly normalizing effects than estradiol-progestogen combinations. The early recognition of girls at risk of developing hyperinsulinaemic androgen excess might enable prevention in childhood.
Collapse
Affiliation(s)
- Lourdes Ibáñez
- Endocrinology Unit, Hospital Sant Joan de Déu, University of Barcelona, Passeig de Sant Joan de Déu, 2, 08950 Esplugues de Llobregat, Barcelona, Spain
| | - Ken K Ong
- MRC Epidemiology Unit, Box 285, Institute of Metabolic Science, Cambridge Biomedical Campus, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Abel López-Bermejo
- Paediatric Endocrinology, Dr Josep Trueta Hospital and Girona Institute for Biomedical Research, Avenue de França s/n, 17007 Girona, Spain
| | - David B Dunger
- Department of Paediatrics, Box 116, Level 8, Addenbrooke's Hospital Hills Road, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Francis de Zegher
- Paediatric Endocrinology, University Hospital Gasthuisberg, University of Leuven, Herestraat 49, 3000 Leuven, Belgium
| |
Collapse
|
33
|
Nigro M, Santos AT, Barthem CS, Louzada RAN, Fortunato RS, Ketzer LA, Carvalho DP, de Meis L. A change in liver metabolism but not in brown adipose tissue thermogenesis is an early event in ovariectomy-induced obesity in rats. Endocrinology 2014; 155:2881-91. [PMID: 24914935 DOI: 10.1210/en.2013-1385] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Menopause is associated with increased visceral adiposity and disrupted glucose homeostasis, but the underlying molecular mechanisms related to these metabolic changes are still elusive. Brown adipose tissue (BAT) plays a key role in energy expenditure that may be regulated by sexual steroids, and alterations in glucose homeostasis could precede increased weight gain after ovariectomy. Thus, the aim of this work was to evaluate the metabolic pathways in both the BAT and the liver that may be disrupted early after ovariectomy. Ovariectomized (OVX) rats had increased food efficiency as early as 12 days after ovariectomy, which could not be explained by differences in feces content. Analysis of isolated BAT mitochondria function revealed no differences in citrate synthase activity, uncoupling protein 1 expression, oxygen consumption, ATP synthesis, or heat production in OVX rats. The addition of GDP and BSA to inhibit uncoupling protein 1 decreased oxygen consumption in BAT mitochondria equally in both groups. Liver analysis revealed increased triglyceride content accompanied by decreased levels of phosphorylated AMP-activated protein kinase and phosphorylated acetyl-CoA carboxylase in OVX animals. The elevated expression of gluconeogenic enzymes in OVX and OVX + estradiol rats was not associated with alterations in glucose tolerance test or in serum insulin but was coincident with higher glucose disposal during the pyruvate tolerance test. Although estradiol treatment prevented the ovariectomy-induced increase in body weight and hepatic triglyceride and cholesterol accumulation, it was not able to prevent increased gluconeogenesis. In conclusion, the disrupted liver glucose homeostasis after ovariectomy is neither caused by estradiol deficiency nor is related to increased body mass.
Collapse
Affiliation(s)
- Mariana Nigro
- Laboratório de Bioenergética (M.N., A.T.S., C.S.B., L.A.K., L.d.M.), Instituto de Bioquímica Médica, Laboratório de Radiobiologia Molecular (R.S.F.) and Laboratório de Fisiologia Endócrina Doris Rosenthal (R.A.N.L., D.P.C.), Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Role of AMP-activated protein kinase in adipose tissue metabolism and inflammation. Clin Sci (Lond) 2013; 124:491-507. [PMID: 23298225 DOI: 10.1042/cs20120536] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AMPK (AMP-activated protein kinase) is a key regulator of cellular and whole-body energy balance. AMPK phosphorylates and regulates many proteins concerned with nutrient metabolism, largely acting to suppress anabolic ATP-consuming pathways while stimulating catabolic ATP-generating pathways. This has led to considerable interest in AMPK as a therapeutic target for the metabolic dysfunction observed in obesity and insulin resistance. The role of AMPK in skeletal muscle and the liver has been extensively studied, such that AMPK has been demonstrated to inhibit synthesis of fatty acids, cholesterol and isoprenoids, hepatic gluconeogenesis and translation while increasing fatty acid oxidation, muscle glucose transport, mitochondrial biogenesis and caloric intake. The role of AMPK in the other principal metabolic and insulin-sensitive tissue, adipose, remains poorly characterized in comparison, yet increasing evidence supports an important role for AMPK in adipose tissue function. Obesity is characterized by hypertrophy of adipocytes and the development of a chronic sub-clinical pro-inflammatory environment in adipose tissue, leading to increased infiltration of immune cells. This combination of dysfunctional hypertrophic adipocytes and a pro-inflammatory environment contributes to insulin resistance and the development of Type 2 diabetes. Exciting recent studies indicate that AMPK may not only influence metabolism in adipocytes, but also act to suppress this pro-inflammatory environment, such that targeting AMPK in adipose tissue may be desirable to normalize adipose dysfunction and inflammation. In the present review, we discuss the role of AMPK in adipose tissue, focussing on the regulation of carbohydrate and lipid metabolism, adipogenesis and pro-inflammatory pathways in physiological and pathophysiological conditions.
Collapse
|
35
|
Ferguson RD, Gallagher EJ, Scheinman EJ, Damouni R, LeRoith D. The epidemiology and molecular mechanisms linking obesity, diabetes, and cancer. VITAMINS AND HORMONES 2013; 93:51-98. [PMID: 23810003 DOI: 10.1016/b978-0-12-416673-8.00010-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The worldwide epidemic of obesity is associated with increasing rates of the metabolic syndrome and type 2 diabetes. Epidemiological studies have reported that these conditions are linked to increased rates of cancer incidence and mortality. Obesity, particularly abdominal obesity, is associated with insulin resistance and the development of dyslipidemia, hyperglycemia, and ultimately type 2 diabetes. Although many metabolic abnormalities occur with obesity and type 2 diabetes, insulin resistance and hyperinsulinemia appear to be central to these conditions and may contribute to dyslipidemia and altered levels of circulating estrogens and androgens. In this review, we will discuss the epidemiological and molecular links between obesity, type 2 diabetes, and cancer, and how hyperinsulinemia and dyslipidemia may contribute to cancer development. We will discuss how these metabolic abnormalities may interact with estrogen signaling in breast cancer growth. Finally, we will discuss the effects of type 2 diabetes medications on cancer risk.
Collapse
Affiliation(s)
- Rosalyn D Ferguson
- Division of Endocrinology, Diabetes and Bone Diseases, Samuel Bronfman Department of Medicine, Mount Sinai School of Medicine, P.O. Box 1055, New York, USA
| | | | | | | | | |
Collapse
|
36
|
Gathercole LL, Morgan SA, Tomlinson JW. Hormonal Regulation of Lipogenesis. VITAMINS & HORMONES 2013; 91:1-27. [DOI: 10.1016/b978-0-12-407766-9.00001-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
37
|
Wang X, Zhao X, Gao X, Mei Y, Wu M. A new role of p53 in regulating lipid metabolism. J Mol Cell Biol 2012; 5:147-50. [PMID: 23258697 DOI: 10.1093/jmcb/mjs064] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
|
38
|
Tiano JP, Mauvais-Jarvis F. Molecular mechanisms of estrogen receptors' suppression of lipogenesis in pancreatic β-cells. Endocrinology 2012; 153:2997-3005. [PMID: 22564979 PMCID: PMC3380304 DOI: 10.1210/en.2011-1980] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The gonadal steroid, 17β-estradiol (E2), suppresses pancreatic islet fatty acid and glycerolipid synthesis and prevents β-cell failure in rodent models of type 2 diabetes. β-Cell estrogen receptors (ER) mediate these actions by suppressing the expression and enzymatic activity of fatty acid synthase (FAS). Here, we explored the mechanism of FAS suppression. We show that E2, and pharmacological agonists for ERα, ERβ, and the G protein-coupled ER, suppress mRNA and protein expression of the transcriptional regulators of FAS, namely, sterol regulatory element-binding protein 1c (SREBP1c) and carbohydrate response element binding protein (ChREBP) in insulin-secreting INS-1 cells. ER suppress SREBP1c and ChREBP mRNA and protein expression via an extranuclear localization. Using two mouse lines with pancreas-specific null deletion of either ERα or the signal transducer and activator of transcription 3 (STAT3), we show that ERα activation in vivo reduces SREBP1c and ChREBP mRNA expression via a direct islet action involving STAT3 activation. The master regulators of lipogenesis, liver X receptor (LXR) α and β, transcriptionally up-regulate SREBP1c and ChREBP. We find that activation of ERα, ERβ, and G protein-coupled ER suppresses LXR's mRNA expression in INS-1 cells. We also observe that activation of ERα in mouse islets in vivo suppresses LXR mRNA in a STAT3-dependent manner. Finally, we show that E2 also activates and uses AMP-activated protein kinase in INS-1 cells to suppress SREBP1c protein expression. This study identifies extranuclear ER pathways involving STAT3 and AMP-activated protein kinase in the genetic control of lipogenesis with therapeutic implications to protect β-cells in type 2 diabetes.
Collapse
Affiliation(s)
- Joseph P Tiano
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, Illinois 60611, USA
| | | |
Collapse
|
39
|
Anderson S, Oyama TT, Lindsley JN, Schutzer WE, Beard DR, Gattone VH, Komers R. 2-Hydroxyestradiol slows progression of experimental polycystic kidney disease. Am J Physiol Renal Physiol 2011; 302:F636-45. [PMID: 22160773 DOI: 10.1152/ajprenal.00265.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Male gender is a risk factor for progression of polycystic kidney disease (PKD). 17β-Estradiol (E2) protects experimentally, but clinical use is limited by adverse effects. Novel E2 metabolites provide many benefits of E2 without stimulating the estrogen receptor, and thus may be safer. We hypothesized that E2 metabolites are protective in a model of PKD. Studies were performed in male control Han:SPRD rats, and in cystic males treated with orchiectomy, 2-methoxyestradiol, 2-hydroxyestradiol (2-OHE), or vehicle, from age 3 to 12 wk. Cystic rats exhibited renal functional impairment (∼50% decrease in glomerular filtration and renal plasma flow rates, P < 0.05) and substantial cyst development (20.5 ± 2.0% of cortex area). 2-OHE was the most effective in limiting cysts (6.0 ± 0.7% of cortex area, P < 0.05 vs. vehicle-treated cystic rats) and preserving function, in association with suppression of proliferation, apoptosis, and angiogenesis markers. Downregulation of p21 expression and increased expression of Akt, the mammalian target of rapamycin (mTOR), and some of its downstream effectors were significantly reversed by 2-OHE. Thus, 2-OHE limits disease progression in a cystic rodent model. Mechanisms include reduced renal cell proliferation, apoptosis, and angiogenesis. These effects may be mediated, at least in part, by preservation of p21 and suppression of Akt and mTOR. Estradiol metabolites may represent a novel, safe intervention to slow progression of PKD.
Collapse
Affiliation(s)
- Sharon Anderson
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health & Science University, Portland, OR 97239, USA.
| | | | | | | | | | | | | |
Collapse
|