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Heitmann T, Liao G, Ernst G, Poslusney M, van Kralingen T, Li Y, Masi M, DePasquale M, Buchler I, Wei H, Carr GV, Shlevkov E, Lu M, Jessen H, Barrow JC. Identification and Characterization of a Blood-Brain Barrier Penetrant Inositol Hexakisphosphate Kinase (IP6K) Inhibitor. J Med Chem 2024; 67:13639-13665. [PMID: 39096294 DOI: 10.1021/acs.jmedchem.4c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2024]
Abstract
Inositol hexakisphosphate kinases (IP6Ks) have been studied for their role in glucose homeostasis, metabolic disease, fatty liver disease, chronic kidney disease, neurological development, and psychiatric disease. IP6Ks phosphorylate inositol hexakisphosphate (IP6) to the pyrophosphate, 5-diphosphoinositol-1,2,3,4,6-pentakisphosphate (5-IP7). Most of the currently known potent IP6K inhibitors contain a critical carboxylic acid which limits blood-brain barrier (BBB) penetration. In this work, the synthesis and testing of a variety of carboxylic acid isosteres resulted in several new compounds with improved BBB penetration. The most promising compound has an IP6K1 IC50 of 16 nM with an improved brain/plasma ratio and a favorable pharmacokinetic profile. This series of brain penetrant compounds may be used to investigate the role of IP6Ks in CNS disorders.
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Affiliation(s)
- Tyler Heitmann
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Gangling Liao
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Glen Ernst
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Michael Poslusney
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Thomas van Kralingen
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ye Li
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Megan Masi
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
| | - Michael DePasquale
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ingrid Buchler
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Huijun Wei
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Gregory V Carr
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Evgeny Shlevkov
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Mengsi Lu
- Institute of Organic Chemistry and CIBSS─Centre for Integrative Biological Signaling Studies, Albert-Ludwigs-University, Albertstr. 21, Freiburg 79104, Germany
| | - Henning Jessen
- Institute of Organic Chemistry and CIBSS─Centre for Integrative Biological Signaling Studies, Albert-Ludwigs-University, Albertstr. 21, Freiburg 79104, Germany
| | - James C Barrow
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, United States
- Lieber Institute for Brain Development, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
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Aguirre T, Dornan GL, Hostachy S, Neuenschwander M, Seyffarth C, Haucke V, Schütz A, von Kries JP, Fiedler D. An unconventional gatekeeper mutation sensitizes inositol hexakisphosphate kinases to an allosteric inhibitor. eLife 2023; 12:RP88982. [PMID: 37843983 PMCID: PMC10578927 DOI: 10.7554/elife.88982] [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] [Indexed: 10/18/2023] Open
Abstract
Inositol hexakisphosphate kinases (IP6Ks) are emerging as relevant pharmacological targets because a multitude of disease-related phenotypes has been associated with their function. While the development of potent IP6K inhibitors is gaining momentum, a pharmacological tool to distinguish the mammalian isozymes is still lacking. Here, we implemented an analog-sensitive approach for IP6Ks and performed a high-throughput screen to identify suitable lead compounds. The most promising hit, FMP-201300, exhibited high potency and selectivity toward the unique valine gatekeeper mutants of IP6K1 and IP6K2, compared to the respective wild-type (WT) kinases. Biochemical validation experiments revealed an allosteric mechanism of action that was corroborated by hydrogen deuterium exchange mass spectrometry measurements. The latter analysis suggested that displacement of the αC helix, caused by the gatekeeper mutation, facilitates the binding of FMP-201300 to an allosteric pocket adjacent to the ATP-binding site. FMP-201300 therefore serves as a valuable springboard for the further development of compounds that can selectively target the three mammalian IP6Ks; either as analog-sensitive kinase inhibitors or as an allosteric lead compound for the WT kinases.
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Affiliation(s)
- Tim Aguirre
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
- Institut für Chemie, Humboldt-Universität zu BerlinBerlinGermany
| | - Gillian L Dornan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Sarah Hostachy
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | | | - Carola Seyffarth
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Anja Schütz
- Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz Association (MDC)BerlinGermany
| | | | - Dorothea Fiedler
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
- Institut für Chemie, Humboldt-Universität zu BerlinBerlinGermany
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Heitmann T, Barrow JC. The Role of Inositol Hexakisphosphate Kinase in the Central Nervous System. Biomolecules 2023; 13:1317. [PMID: 37759717 PMCID: PMC10526494 DOI: 10.3390/biom13091317] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/23/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023] Open
Abstract
Inositol is a unique biological small molecule that can be phosphorylated or even further pyrophosphorylated on each of its six hydroxyl groups. These numerous phosphorylation states of inositol along with the kinases and phosphatases that interconvert them comprise the inositol phosphate signaling pathway. Inositol hexakisphosphate kinases, or IP6Ks, convert the fully mono-phosphorylated inositol to the pyrophosphate 5-IP7 (also denoted IP7). There are three isoforms of IP6K: IP6K1, 2, and 3. Decades of work have established a central role for IP6Ks in cell signaling. Genetic and pharmacologic manipulation of IP6Ks in vivo and in vitro has shown their importance in metabolic disease, chronic kidney disease, insulin signaling, phosphate homeostasis, and numerous other cellular and physiologic processes. In addition to these peripheral processes, a growing body of literature has shown the role of IP6Ks in the central nervous system (CNS). IP6Ks have a key role in synaptic vesicle regulation, Akt/GSK3 signaling, neuronal migration, cell death, autophagy, nuclear translocation, and phosphate homeostasis. IP6Ks' regulation of these cellular processes has functional implications in vivo in behavior and CNS anatomy.
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Affiliation(s)
- Tyler Heitmann
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, 725 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
- The Lieber Institute for Brain Development, 855 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
| | - James C. Barrow
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, 725 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
- The Lieber Institute for Brain Development, 855 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
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Kwon S, Hyeon JS, Jung Y, Li L, An JN, Kim YC, Yang SH, Kim T, Kim DK, Lim CS, Hwang GS, Lee JP. Urine myo-inositol as a novel prognostic biomarker for diabetic kidney disease: a targeted metabolomics study using nuclear magnetic resonance. Kidney Res Clin Pract 2023; 42:445-459. [PMID: 37551126 PMCID: PMC10407640 DOI: 10.23876/j.krcp.22.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 12/31/2022] [Accepted: 01/12/2023] [Indexed: 08/09/2023] Open
Abstract
BACKGROUND As a leading cause of chronic kidney disease, clinical demand for noninvasive biomarkers of diabetic kidney disease (DKD) beyond proteinuria is increasing. Metabolomics is a popular method to identify mechanisms and biomarkers. We investigated urinary targeted metabolomics in DKD patients. METHODS We conducted a targeted metabolomics study of 26 urinary metabolites in consecutive patients with DKD stage 1 to 5 (n = 208) and healthy controls (n = 26). The relationships between estimated glomerular filtration rate (eGFR) or urine protein-creatinine ratio (UPCR) and metabolites were evaluated. Multivariate Cox analysis was used to estimate relationships between urinary metabolites and the target outcome, end-stage renal disease (ESRD). C statistics and time-dependent receiver operating characteristics (ROC) were used to assess diagnostic validity. RESULTS During a median 4.5 years of follow-up, 103 patients (44.0%) progressed to ESRD and 65 (27.8%) died. The median fold changes of nine metabolites belonged to monosaccharide and tricarboxylic acid (TCA) cycle metabolites tended to increase with DKD stage. Myo-inositol, choline, and citrates were correlated with eGFR and choline, while mannose and myo-inositol were correlated with UPCR. Elevated urinary monosaccharide and TCA cycle metabolites showed associations with increased morality and ESRD progression. The predictive power of ESRD progression was high, in the order of choline, myo-inositol, and citrate. Although urinary metabolites alone were less predictive than serum creatinine or UPCR, myo-inositol had additive effect with serum creatinine and UPCR. In time-dependent ROC, myo-inositol was more predictive than UPCR of 1-year ESRD progression prediction. CONCLUSION Myo-inositol can be used as an additive biomarker of ESRD progression in DKD.
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Affiliation(s)
- Soie Kwon
- Department of Internal Medicine, Chung-Ang University Heukseok Hospital, Seoul, Republic of Korea
- Department of Clinical Medical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jin Seong Hyeon
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea
- Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, Republic of Korea
| | - Youngae Jung
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea
| | - Lilin Li
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Critical Care Medicine, Yanbian University Hospital, Yanji, China
| | - Jung Nam An
- Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Yong Chul Kim
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Seung Hee Yang
- Kidney Research Institute, Seoul National University Medical Research Center , Seoul, Republic of Korea
| | - Tammy Kim
- Institute of Life and Death Studies, Hallym University, Chuncheon, Republic of Korea
| | - Dong Ki Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Chun Soo Lim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul, Republic of Korea
| | - Geum-Sook Hwang
- Western Seoul Center, Korea Basic Science Institute, Seoul, Republic of Korea
- Division of Nephrology, Department of Internal Medicine-Nephrology, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Jung Pyo Lee
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
- Division of Nephrology, Department of Internal Medicine-Nephrology, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
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Yuan Y, Long H, Zhou Z, Fu Y, Jiang B. PI3K-AKT-Targeting Breast Cancer Treatments: Natural Products and Synthetic Compounds. Biomolecules 2023; 13:biom13010093. [PMID: 36671478 PMCID: PMC9856042 DOI: 10.3390/biom13010093] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/16/2022] [Accepted: 12/30/2022] [Indexed: 01/03/2023] Open
Abstract
Breast cancer is the most commonly diagnosed cancer in women. The high incidence of breast cancer, which is continuing to rise, makes treatment a significant challenge. The PI3K-AKT pathway and its downstream targets influence various cellular processes. In recent years, mounting evidence has shown that natural products and synthetic drugs targeting PI3K-AKT signaling have the potential to treat breast cancer. In this review, we discuss the role of the PI3K-AKT signaling pathway in the occurrence and development of breast cancer and highlight PI3K-AKT-targeting natural products and drugs in clinical trials for the treatment of breast cancer.
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Affiliation(s)
- Yeqin Yuan
- Medical Research Center, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha 410004, China
| | - Huizhi Long
- School of Pharmacy, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Ziwei Zhou
- School of Pharmacy, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Yuting Fu
- Medical Research Center, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha 410004, China
| | - Binyuan Jiang
- Medical Research Center, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha 410004, China
- Department of Clinical Laboratory, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha 410004, China
- Correspondence:
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Whitfield H, Laurendon C, Rochell S, Dridi S, Lee S, Dale T, York T, Kuehn I, Bedford M, Brearley C. Effect of phytase supplementation on plasma and organ myo-inositol content and erythrocyte inositol phosphates as pertaining to breast meat quality issues in chickens. JOURNAL OF APPLIED ANIMAL NUTRITION 2022. [DOI: 10.3920/jaan2021.0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
‘Woody breast’ (WB) and ‘white striping’ in broiler meat is a global problem. With unknown etiology, WB negatively impacts bird health, welfare and is a significant economic burden to the poultry industry. New evidence has shown that WB is associated with dysregulation in systemic and breast muscle-oxygen homeostasis, resulting in hypoxia and anaemia. However, it has been observed that phytase (Quantum Blue (QB) a modified, E. coli-derived 6-phytase) super dosing can reverse dysregulation of muscle-oxygen homeostasis and reduces WB severity by ~5%. The objective of this study was to assess whether levels of Ins(1,3,4,5,6)P5, the main allosteric regulator of haemoglobin, are influenced by changes in plasma myo-inositol arising from super dosing with phytase. To enable this, methods suitable for measurement of myo-inositol in tissues and inositol phosphates in blood were developed. Data were collected from independent trials, including male Ross 308 broilers fed low and adequate calcium/available phosphate (Ca/AvP) diets supplemented with QB at 1,500 phytase units (FTU)/kg, which simultaneously decreased gizzard InsP6 (P<0.001) and increased gizzard myo-inositol (P<0.001). Similarly, male Cobb 500 broiler chicks fed a negative control (NC) diet deficient in AvP, Ca and sodium or diet supplemented with the QB phytase at 500, 1000 or 2,000 FTU/kg increased plasma (P<0.001) and liver (P=0.007) myo-inositol of 18d-old birds at 2,000 FTU/kg. Finally, QB supplementation of Cobb 500 breeder flock diet at 1,250 FTU/kg increased blood myo-inositol (P<0.001) and erythrocyte Ins(1,3,4,5,6)P5 (P=0.011) of their 1d-old hatchlings. These data confirmed the ability of phytase to modulate inositol phosphate pathways by provision of metabolic precursors of important signalling molecules. The ameliorations of WB afforded by super doses of phytase may include modulation of hypoxia pathways that also involve inositol signalling molecules. Elevations of erythrocyte Ins(1,3,4,5,6)P5 by phytase supplementation may enhance systemic oxygen carrying capacity, an important factor in the amelioration of WB and WS myopathy.
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Affiliation(s)
- H. Whitfield
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - C. Laurendon
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - S.J. Rochell
- University of Arkansas, Center of Excellence for Poultry Science, University of Arkansas, 1260 W. Maple, POSC O-406, Fayetteville, AR 72701, USA
| | - S. Dridi
- University of Arkansas, Center of Excellence for Poultry Science, University of Arkansas, 1260 W. Maple, POSC O-406, Fayetteville, AR 72701, USA
| | - S.A. Lee
- AB Vista, Woodstock Ct, Marlborough, Wiltshire, SN8 4AN, United Kingdom
| | - T. Dale
- AB Vista, Woodstock Ct, Marlborough, Wiltshire, SN8 4AN, United Kingdom
| | - T. York
- AB Vista, Woodstock Ct, Marlborough, Wiltshire, SN8 4AN, United Kingdom
| | - I. Kuehn
- AB Vista, Feldbergstrasse 78, 64293 Darmstadt, Germany
| | - M.R. Bedford
- AB Vista, Woodstock Ct, Marlborough, Wiltshire, SN8 4AN, United Kingdom
| | - C.A Brearley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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Sadri S, Sharifi G, Jalali Dehkordi K. Nano branched-chain amino acids enhance the effect of uphill (concentric) and downhill (eccentric) treadmill exercise on muscle gene expression of Akt and mTOR on aged rats. SPORT SCIENCES FOR HEALTH 2021. [DOI: 10.1007/s11332-021-00828-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Insulin Signal Transduction Perturbations in Insulin Resistance. Int J Mol Sci 2021; 22:ijms22168590. [PMID: 34445300 PMCID: PMC8395322 DOI: 10.3390/ijms22168590] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/23/2021] [Accepted: 07/28/2021] [Indexed: 12/11/2022] Open
Abstract
Type 2 diabetes mellitus is a widespread medical condition, characterized by high blood glucose and inadequate insulin action, which leads to insulin resistance. Insulin resistance in insulin-responsive tissues precedes the onset of pancreatic β-cell dysfunction. Multiple molecular and pathophysiological mechanisms are involved in insulin resistance. Insulin resistance is a consequence of a complex combination of metabolic disorders, lipotoxicity, glucotoxicity, and inflammation. There is ample evidence linking different mechanistic approaches as the cause of insulin resistance, but no central mechanism is yet described as an underlying reason behind this condition. This review combines and interlinks the defects in the insulin signal transduction pathway of the insulin resistance state with special emphasis on the AGE-RAGE-NF-κB axis. Here, we describe important factors that play a crucial role in the pathogenesis of insulin resistance to provide directionality for the events. The interplay of inflammation and oxidative stress that leads to β-cell decline through the IAPP-RAGE induced β-cell toxicity is also addressed. Overall, by generating a comprehensive overview of the plethora of mechanisms involved in insulin resistance, we focus on the establishment of unifying mechanisms to provide new insights for the future interventions of type 2 diabetes mellitus.
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Role of Inositols and Inositol Phosphates in Energy Metabolism. Molecules 2020; 25:molecules25215079. [PMID: 33139672 PMCID: PMC7663797 DOI: 10.3390/molecules25215079] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/27/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022] Open
Abstract
Recently, inositols, especially myo-inositol and inositol hexakisphosphate, also known as phytic acid or IP6, with their biological activities received much attention for their role in multiple health beneficial effects. Although their roles in cancer treatment and prevention have been extensively reported, interestingly, they may also have distinctive properties in energy metabolism and metabolic disorders. We review inositols and inositol phosphate metabolism in mammalian cells to establish their biological activities and highlight their potential roles in energy metabolism. These molecules are known to decrease insulin resistance, increase insulin sensitivity, and have diverse properties with importance from cell signaling to metabolism. Evidence showed that inositol phosphates might enhance the browning of white adipocytes and directly improve insulin sensitivity through adipocytes. In addition, inositol pyrophosphates containing high-energy phosphate bonds are considered in increasing cellular energetics. Despite all recent advances, many aspects of the bioactivity of inositol phosphates are still not clear, especially their effects on insulin resistance and alteration of metabolism, so more research is needed.
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Palomino-Schätzlein M, Mayneris-Perxachs J, Caballano-Infantes E, Rodríguez MA, Palomo-Buitrago ME, Xiao X, Mares R, Ricart W, Simó R, Herance JR, Fernández-Real JM. Combining metabolic profiling of plasma and faeces as a fingerprint of insulin resistance in obesity. Clin Nutr 2020; 39:2292-2300. [DOI: 10.1016/j.clnu.2019.10.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 10/17/2019] [Accepted: 10/19/2019] [Indexed: 12/13/2022]
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Mukherjee S, Haubner J, Chakraborty A. Targeting the Inositol Pyrophosphate Biosynthetic Enzymes in Metabolic Diseases. Molecules 2020; 25:molecules25061403. [PMID: 32204420 PMCID: PMC7144392 DOI: 10.3390/molecules25061403] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 12/12/2022] Open
Abstract
In mammals, a family of three inositol hexakisphosphate kinases (IP6Ks) synthesizes the inositol pyrophosphate 5-IP7 from IP6. Genetic deletion of Ip6k1 protects mice from high fat diet induced obesity, insulin resistance and fatty liver. IP6K1 generated 5-IP7 promotes insulin secretion from pancreatic β-cells, whereas it reduces insulin signaling in metabolic tissues by inhibiting the protein kinase Akt. Thus, IP6K1 promotes high fat diet induced hyperinsulinemia and insulin resistance in mice while its deletion has the opposite effects. IP6K1 also promotes fat accumulation in the adipose tissue by inhibiting the protein kinase AMPK mediated energy expenditure. Genetic deletion of Ip6k3 protects mice from age induced fat accumulation and insulin resistance. Accordingly, the pan IP6K inhibitor TNP [N2-(m-trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates obesity, insulin resistance and fatty liver in diet induced obese mice by improving Akt and AMPK mediated insulin sensitivity and energy expenditure. TNP also protects mice from bone loss, myocardial infarction and ischemia reperfusion injury. Thus, the IP6K pathway is a potential target in obesity and other metabolic diseases. Here, we summarize the studies that established IP6Ks as a potential target in metabolic diseases. Further studies will reveal whether inhibition of this pathway has similar pleiotropic benefits on metabolic health of humans.
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Cho Y, Lee H, Park HK, Choe EY, Wang HJ, Kim RH, Kim Y, Kang ES. Differential Diabetogenic Effect of Pitavastatin and Rosuvastatin, in vitro and in vivo. J Atheroscler Thromb 2019; 27:429-440. [PMID: 31527323 PMCID: PMC7242225 DOI: 10.5551/jat.50039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Aim: Most statins increase the risk of new-onset diabetes. Unlike other statins, pitavastatin is reported to exert neutral effects on serum glucose level, but the precise mechanism is unknown. Methods: Eight-week-old male C57BL/6J mice (n = 26) were fed high-fat diet (HFD, 45% fat) with 0.01% placebo, rosuvastatin, or pitavastatin for 12 weeks. Cultured HepG2, C2C12, and 3T3-L1 cells and visceral adipocytes from HFD-fed mice were treated with vehicle or 10 µM statins for 24 h. The effects of pitavastatin and rosuvastatin on intracellular insulin signaling and glucose transporter 4 (GLUT4) translocation were evaluated. Results: After 12 weeks, the fasting blood glucose level was significantly lower in pitavastatin-treated group than in rosuvastatin-treated group (115.2 ± 7.0 versus 137.4 ± 22.3 mg/dL, p = 0.024). Insulin tolerance significantly improved in pitavastatin-treated group as compared with rosuvastatin-treated group, and no significant difference was observed in glucose tolerance. Although plasma adiponectin and insulin levels were not different between the two statin treatment groups, the insulin-induced protein kinase B phosphorylation was weakly attenuated in pitavastatin-treated adipocytes than in rosuvastatin-treated adipocytes. Furthermore, minor attenuation in insulin-induced GLUT4 translocation to the plasma membrane of adipocytes was observed in pitavastatin-treated group. Conclusion: Pitavastatin showed lower diabetogenic effects than rosuvastatin in mice that may be mediated by minor attenuations in insulin signaling in adipocytes.
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Affiliation(s)
- Yongin Cho
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine
| | - Hyangkyu Lee
- Yonsei University College of Nursing, Mo-Im Kim Nursing Research Institute, Biobehavioral Research Center
| | - Hyun Ki Park
- Yonsei University College of Nursing, Mo-Im Kim Nursing Research Institute, Biobehavioral Research Center
| | - Eun Yeong Choe
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine
| | - Hye Jin Wang
- Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine
| | - Ryeong-Hyeon Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine
| | - Youjin Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine
| | - Eun Seok Kang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine.,Brain Korea 21 PLUS Project for Medical Science; Yonsei University College of Medicine
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Barclay RD, Burd NA, Tyler C, Tillin NA, Mackenzie RW. The Role of the IGF-1 Signaling Cascade in Muscle Protein Synthesis and Anabolic Resistance in Aging Skeletal Muscle. Front Nutr 2019; 6:146. [PMID: 31552262 PMCID: PMC6746962 DOI: 10.3389/fnut.2019.00146] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 08/23/2019] [Indexed: 12/14/2022] Open
Abstract
Sarcopenia is defined as the combined loss of skeletal muscle strength, function, and/or mass with aging. This degenerative loss of muscle mass is associated with poor quality of life and early mortality humans. The loss of muscle mass occurs due to acute changes in daily muscle net protein balance (NPB). It is generally believed a poor NPB occurs due to reduced muscle protein synthetic responses to exercise, dietary amino acid availability, or an insensitivity of insulin to suppress breakdown. Hence, aging muscles appear to be resistant to the anabolic action of exercise and protein (amino acids or hormonal) when compared to their younger counterparts. The mechanisms that underpin anabolic resistance to anabolic stimuli (protein and resistance exercise) are multifactorial and may be partly driven by poor lifestyle choices (increased sedentary time and reduced dietary protein intake) as well as an inherent dysregulated mechanism in old muscles irrespective of the environmental stimuli. The insulin like growth factor 1 (IGF-1), Akt /Protein Kinase B and mechanistic target of rapamycin (mTOR) pathway is the primary driver between mechanical contraction and protein synthesis and may be a site of dysregulation between old and younger people. Therefore, our review aims to describe and summarize the differences seen in older muscle in this pathway in response to resistance exercise (RE) and describe approaches that researchers have sought out to maximize the response in muscle. Furthermore, this review will present the hypothesis that inositol hexakisphosphate kinase 1 (IP6K1) may be implicated in IGF-1 signaling and thus sarcopenia, based on recent evidence that IGF-1 and insulin share some intracellular bound signaling events and that IP6K1 has been implicated in skeletal muscle insulin resistance.
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Affiliation(s)
- Richie D Barclay
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Nicholas A Burd
- Division of Nutritional Sciences, Department of Kinesiology and Community Health, University of Illinois, Urbana, IL, United States
| | - Christopher Tyler
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Neale A Tillin
- Department of Life Sciences, University of Roehampton, London, United Kingdom
| | - Richard W Mackenzie
- Department of Life Sciences, University of Roehampton, London, United Kingdom
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MicroRNAs as Regulators of Insulin Signaling: Research Updates and Potential Therapeutic Perspectives in Type 2 Diabetes. Int J Mol Sci 2018; 19:ijms19123705. [PMID: 30469501 PMCID: PMC6321520 DOI: 10.3390/ijms19123705] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/08/2018] [Accepted: 11/17/2018] [Indexed: 12/21/2022] Open
Abstract
The insulin signaling pathway is composed of a large number of molecules that positively or negatively modulate insulin specific signal transduction following its binding to the cognate receptor. Given the importance of the final effects of insulin signal transduction, it is conceivable that many regulators are needed in order to tightly control the metabolic or proliferative functional outputs. MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively modulate gene expression through their specific binding within the 3′UTR sequence of messenger RNA (mRNA), thus causing mRNA decoy or translational inhibition. In the last decade, miRNAs have been addressed as pivotal cellular rheostats which control many fundamental signaling pathways, including insulin signal transduction. Several studies demonstrated that multiple alterations of miRNAs expression or function are relevant for the development of insulin resistance in type 2 diabetes (T2D); such alterations have been highlighted in multiple insulin target organs including liver, muscles, and adipose tissue. Indirectly, miRNAs have been identified as modulators of inflammation-derived insulin resistance, by controlling/tuning the activity of innate immune cells in insulin target tissues. Here, we review main findings on miRNA functions as modulators of insulin signaling in physiologic- or in T2D insulin resistance- status. Additionally, we report the latest hypotheses of prospective therapies involving miRNAs as potential targets for future drugs in T2D.
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15
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Chakraborty A. The inositol pyrophosphate pathway in health and diseases. Biol Rev Camb Philos Soc 2018; 93:1203-1227. [PMID: 29282838 PMCID: PMC6383672 DOI: 10.1111/brv.12392] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 11/28/2017] [Accepted: 12/05/2017] [Indexed: 12/11/2022]
Abstract
Inositol pyrophosphates (IPPs) are present in organisms ranging from plants, slime moulds and fungi to mammals. Distinct classes of kinases generate different forms of energetic diphosphate-containing IPPs from inositol phosphates (IPs). Conversely, polyphosphate phosphohydrolase enzymes dephosphorylate IPPs to regenerate the respective IPs. IPPs and/or their metabolizing enzymes regulate various cell biological processes by modulating many proteins via diverse mechanisms. In the last decade, extensive research has been conducted in mammalian systems, particularly in knockout mouse models of relevant enzymes. Results obtained from these studies suggest impacts of the IPP pathway on organ development, especially of brain and testis. Conversely, deletion of specific enzymes in the pathway protects mice from various diseases such as diet-induced obesity (DIO), type-2 diabetes (T2D), fatty liver, bacterial infection, thromboembolism, cancer metastasis and aging. Furthermore, pharmacological inhibition of the same class of enzymes in mice validates the therapeutic importance of this pathway in cardio-metabolic diseases. This review critically analyses these findings and summarizes the significance of the IPP pathway in mammalian health and diseases. It also evaluates benefits and risks of targeting this pathway in disease therapies. Finally, future directions of mammalian IPP research are discussed.
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Affiliation(s)
- Anutosh Chakraborty
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, Saint Louis, MO 63104, U.S.A
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16
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Naufahu J, Elliott B, Markiv A, Dunning-Foreman P, McGrady M, Howard D, Watt P, Mackenzie RWA. High-Intensity Exercise Decreases IP6K1 Muscle Content and Improves Insulin Sensitivity (SI2*) in Glucose-Intolerant Individuals. J Clin Endocrinol Metab 2018; 103:1479-1490. [PMID: 29300979 DOI: 10.1210/jc.2017-02019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 12/20/2017] [Indexed: 12/13/2022]
Abstract
CONTEXT Insulin resistance (IR) in skeletal muscle contributes to whole body hyperglycemia and the secondary complications associated with type 2 diabetes. Inositol hexakisphosphate kinase-1 (IP6K1) may inhibit insulin-stimulated glucose transport in this tissue type. OBJECTIVE Muscle and plasma IP6K1 were correlated with two-compartment models of glucose control in insulin-resistant hyperinsulinemic individuals. Muscle IP6K1 was also compared after two different exercise trials. DESIGN Nine prediabetic [hemoglobin A1c; 6.1% (0.2%)] patients were recruited to take part in a resting control, a continuous exercise (90% of lactate threshold), and a high-intensity exercise trial (6 30-second sprints). Muscle biopsies were drawn before and after each 60-minute trial. A labeled ([6,62H2]glucose) intravenous glucose tolerance test was performed immediately after the second muscle sample. RESULTS Fasting muscle IP6K1 content did not correlate with insulin sensitivity (SI2*) (P = 0.961). High-intensity exercise reduced IP6K1 muscle protein and messenger RNA expression (P = 0.001). There was no effect on protein IP6K1 content after continuous exercise. Akt308 phosphorylation of was significantly greater after high-intensity exercise. Intermittent exercise reduced hepatic glucose production after the same trial. The same intervention also increased SI2*, and this effect was significantly greater compared with the effect of continuous exercise improvements. Our in vitro experiment demonstrated that the chemical inhibition of IP6K1 increased insulin signaling in C2C12 myotubes. CONCLUSIONS The in vivo and in vitro approaches used in the current study suggest that a decrease in muscle IP6K1 may be linked to whole body increases in SI2*. In addition, high-intensity exercise reduces hepatic glucose production in insulin-resistant individuals.
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Affiliation(s)
- Jane Naufahu
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Bradley Elliott
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Anatoliy Markiv
- Biosciences Education, King's College London, London, United Kingdom
| | - Petra Dunning-Foreman
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - Maggie McGrady
- Faculty of Science and Technology, Department of Life Sciences, University of Westminster, London, United Kingdom
| | - David Howard
- Department of Oncology, Charing Cross Hospital, Imperial NHS Trust Hospitals, London, United Kingdom
| | - Peter Watt
- Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
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Kudoh A, Satoh H, Hirai H, Watanabe T, Shimabukuro M. Preliminary Evidence for Adipocytokine Signals in Skeletal Muscle Glucose Uptake. Front Endocrinol (Lausanne) 2018; 9:295. [PMID: 29930536 PMCID: PMC5999789 DOI: 10.3389/fendo.2018.00295] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/17/2018] [Indexed: 02/04/2023] Open
Abstract
The cross talk between the adipose tissue and insulin target tissues is a key mechanism for obesity-associated insulin resistance. However, the precise role of the interaction between the skeletal muscle and adipose tissue for insulin signaling and glucose uptake is questionable. L6 myocytes were co-cultured with or without 3T3-L1 adipocytes (~5 × 103 cells/cm2) up to 24 h. Glucose uptake was evaluated by 2-[3H] deoxyglucose uptake assay. Levels of mRNA expression of Glut1 and Glut4 and mitochondrial enzymes were analyzed by quantitative real-time reverse transcription polymerase chain reaction. Levels of Glut1 and Glut4 protein and phosphorylation of Akt (Ser473 and Thr308) were analyzed by immunoblotting. Study 1: co-culture with 3T3-L1 adipocytes increased glucose uptake in dose- and time-dependent manner in L6 myocytes under insulin-untreated conditions. When co-cultured with 3T3-L1 cells, reactive oxygen species production and levels of Glut1 mRNA and protein were increased in L6 cells, while these changes were abrogated and the glucose uptake partially inhibited by antioxidant treatment. Study 2: co-culture with 3T3-L1 adipocytes suppressed insulin-stimulated glucose uptake in L6 myocytes. Insulin-induced Akt phosphorylation at Ser473 decreased, which was proportional to 3T3-L1 density. Antioxidant treatment partially reversed this effect. Interactions between skeletal muscle and adipose tissues are important for glucose uptake under insulin-untreated or -treated condition through oxygen stress mechanism.
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Affiliation(s)
- Akihiro Kudoh
- Department of Diabetes, Endocrinology, and Metabolism, Fukushima Medical University, Fukushima-City, Japan
- *Correspondence: Akihiro Kudoh, ; Michio Shimabukuro,
| | - Hiroaki Satoh
- Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Hiroyuki Hirai
- Department of Diabetes, Endocrinology, and Metabolism, Fukushima Medical University, Fukushima-City, Japan
| | - Tsuyoshi Watanabe
- Department of Internal Medicine, Fukushima Rosai Hospital, Iwaki, Japan
| | - Michio Shimabukuro
- Department of Diabetes, Endocrinology, and Metabolism, Fukushima Medical University, Fukushima-City, Japan
- *Correspondence: Akihiro Kudoh, ; Michio Shimabukuro,
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Tang S, Wu W, Tang W, Ge Z, Wang H, Hong T, Zhu D, Bi Y. Suppression of Rho-kinase 1 is responsible for insulin regulation of the AMPK/SREBP-1c pathway in skeletal muscle cells exposed to palmitate. Acta Diabetol 2017; 54:635-644. [PMID: 28265821 DOI: 10.1007/s00592-017-0976-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/19/2017] [Indexed: 11/28/2022]
Abstract
AIMS Clinical and experimental data suggest that early insulin therapy could reduce lipotoxicity in subjects and animal models with type 2 diabetes mellitus. However, the underlying mechanisms need to be clarified. Sterol regulatory element-binding protein 1c (SREBP-1c), which is negatively regulated by AMP-activated protein kinase (AMPK), plays a critical role in lipotoxicity and insulin resistance in skeletal muscle cells. Here, we investigated the effect and molecular mechanism of insulin intervention on the AMPK/SREBP-1c pathway in skeletal muscle cells with chronic exposure to palmitic acid (PA). METHODS Male C57BL/6 mice were fed with a high-fat diet for 12 weeks and were then treated with insulin, AMPK inhibitor, or metformin. L6 myotubes incubated with palmitic acid (PA) were treated with insulin or metformin. Dominant-negative AMPKα2 (DN-AMPKα2) lentivirus, AMPKα2 siRNA, or Rho-kinase 1 (ROCK1) siRNA were transfected into PA-treated L6 myotubes. RESULTS We found that the ability of PA to stimulate SREBP-1c and inhibit AMPK was reversed by insulin in L6 cells. Moreover, DN-AMPKα2 lentivirus and AMPKα2 siRNA were transfected into PA-treated L6 myotubes, and the decrease in SREBP-1c expression caused by insulin was blocked by AMPK inhibition independent of the phosphatidylinositol-4,5-biphosphate-3-kinase (PI3K)/AKT pathway. The serine/threonine kinase Rho-kinase (ROCK) 1, a downstream effector of the small G protein RhoA, was activated by PA. Interestingly, knockdown of ROCK1 by siRNA blocked the downregulation of AMPK phosphorylation under PA-treated L6 myotubes, which indicated that ROCK1 mediated the effect of insulin action on AMPK. CONCLUSIONS Our study indicated that insulin reduced lipotoxicity via ROCK1 and then improved AMPK/SREBP-1c signaling in skeletal muscle under PA-induced insulin resistance.
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Affiliation(s)
- Sunyinyan Tang
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China
| | - Wenjun Wu
- Department of Endocrinology, Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu, People's Republic of China
| | - Wenjuan Tang
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China
| | - Zhijuan Ge
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China
| | - Hongdong Wang
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China
| | - Ting Hong
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China
| | - Dalong Zhu
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China.
| | - Yan Bi
- Department of Endocrinology, Drum Tower Hospital Affiliated to the Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China.
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19
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Song ES, Jang H, Guo HF, Juliano MA, Juliano L, Morris AJ, Galperin E, Rodgers DW, Hersh LB. Inositol phosphates and phosphoinositides activate insulin-degrading enzyme, while phosphoinositides also mediate binding to endosomes. Proc Natl Acad Sci U S A 2017; 114:E2826-E2835. [PMID: 28325868 PMCID: PMC5389272 DOI: 10.1073/pnas.1613447114] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Insulin-degrading enzyme (IDE) hydrolyzes bioactive peptides, including insulin, amylin, and the amyloid β peptides. Polyanions activate IDE toward some substrates, yet an endogenous polyanion activator has not yet been identified. Here we report that inositol phosphates (InsPs) and phosphatdidylinositol phosphates (PtdInsPs) serve as activators of IDE. InsPs and PtdInsPs interact with the polyanion-binding site located on an inner chamber wall of the enzyme. InsPs activate IDE by up to ∼95-fold, affecting primarily Vmax The extent of activation and binding affinity correlate with the number of phosphate groups on the inositol ring, with phosphate positional effects observed. IDE binds PtdInsPs from solution, immobilized on membranes, or presented in liposomes. Interaction with PtdInsPs, likely PtdIns(3)P, plays a role in localizing IDE to endosomes, where the enzyme reportedly encounters physiological substrates. Thus, InsPs and PtdInsPs can serve as endogenous modulators of IDE activity, as well as regulators of its intracellular spatial distribution.
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Affiliation(s)
- Eun Suk Song
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536
| | - HyeIn Jang
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536
| | - Hou-Fu Guo
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536
| | - Maria A Juliano
- Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, 04044-020 Sao Paulo, Brazil
| | - Luiz Juliano
- Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, 04044-020 Sao Paulo, Brazil
| | - Andrew J Morris
- Division of Cardiovascular Medicine, University of Kentucky College of Medicine, Lexington, KY 40536
| | - Emilia Galperin
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536
| | - David W Rodgers
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536;
- Center for Structural Biology, University of Kentucky, Lexington, KY 40536
| | - Louis B Hersh
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536;
- Center for Structural Biology, University of Kentucky, Lexington, KY 40536
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Wang X, Hills LB, Huang YH. Lipid and Protein Co-Regulation of PI3K Effectors Akt and Itk in Lymphocytes. Front Immunol 2015; 6:117. [PMID: 25821452 PMCID: PMC4358224 DOI: 10.3389/fimmu.2015.00117] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/02/2015] [Indexed: 12/21/2022] Open
Abstract
The phosphoinositide 3-kinase (PI 3-kinase, PI3K) pathway transduces signals critical for lymphocyte function. PI3K generates the phospholipid PIP3 at the plasma membrane to recruit proteins that contain pleckstrin homology (PH) domains – a conserved domain found in hundreds of mammalian proteins. PH domain–PIP3 interactions allow for rapid signal propagation and confer a spatial component to these signals. The kinases Akt and Itk are key PI3K effectors that bind PIP3 via their PH domains and mediate vital processes – such as survival, activation, and differentiation – in lymphocytes. Here, we review the roles and regulation of PI3K signaling in lymphocytes with a specific emphasis on Akt and Itk. We also discuss these and other PH domain-containing proteins as they relate more broadly to immune cell function. Finally, we highlight the emerging view of PH domains as multifunctional protein domains that often bind both lipid and protein substrates to exert their effects.
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Affiliation(s)
- Xinxin Wang
- California Institute for Biomedical Research , La Jolla, CA , USA
| | - Leonard Benjamin Hills
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Lebanon, NH , USA
| | - Yina Hsing Huang
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth , Lebanon, NH , USA ; Department of Pathology, Geisel School of Medicine at Dartmouth , Lebanon, NH , USA
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21
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Mackenzie RWA, Elliott BT. Akt/PKB activation and insulin signaling: a novel insulin signaling pathway in the treatment of type 2 diabetes. Diabetes Metab Syndr Obes 2014; 7:55-64. [PMID: 24611020 PMCID: PMC3928478 DOI: 10.2147/dmso.s48260] [Citation(s) in RCA: 213] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Type 2 diabetes is a metabolic disease categorized primarily by reduced insulin sensitivity, β-cell dysfunction, and elevated hepatic glucose production. Treatments reducing hyperglycemia and the secondary complications that result from these dysfunctions are being sought after. Two distinct pathways encourage glucose transport activity in skeletal muscle, ie, the contraction-stimulated pathway reliant on Ca(2+)/5'-monophosphate-activated protein kinase (AMPK)-dependent mechanisms and an insulin-dependent pathway activated via upregulation of serine/threonine protein kinase Akt/PKB. Metformin is an established treatment for type 2 diabetes due to its ability to increase peripheral glucose uptake while reducing hepatic glucose production in an AMPK-dependent manner. Peripheral insulin action is reduced in type 2 diabetics whereas AMPK signaling remains largely intact. This paper firstly reviews AMPK and its role in glucose uptake and then focuses on a novel mechanism known to operate via an insulin-dependent pathway. Inositol hexakisphosphate (IP6) kinase 1 (IP6K1) produces a pyrophosphate group at the position of IP6 to generate a further inositol pyrophosphate, ie, diphosphoinositol pentakisphosphate (IP7). IP7 binds with Akt/PKB at its pleckstrin homology domain, preventing interaction with phosphatidylinositol 3,4,5-trisphosphate, and therefore reducing Akt/PKB membrane translocation and insulin-stimulated glucose uptake. Novel evidence suggesting a reduction in IP7 production via IP6K1 inhibition represents an exciting therapeutic avenue in the treatment of insulin resistance. Metformin-induced activation of AMPK is a key current intervention in the management of type 2 diabetes. However, this treatment does not seem to improve peripheral insulin resistance. In light of this evidence, we suggest that inhibition of IP6K1 may increase insulin sensitivity and provide a novel research direction in the treatment of insulin resistance.
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Affiliation(s)
- Richard WA Mackenzie
- Department of Human and Health Sciences, Facility of Science and Technology, University of Westminster, London, UK
- Correspondence: Richard WA Mackenzie, Department of Human and Health Sciences, Facility of Science and Technology, University of Westminster, 115 New Cavendish St, London W1W 6UW, UK, Tel +44 020 7911 5000 ext 3811, Email
| | - Bradley T Elliott
- Department of Human and Health Sciences, Facility of Science and Technology, University of Westminster, London, UK
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Zhang Y, Ma T, Yang S, Xia M, Xu J, An H, Yang Y, Li S. High-mobility group A1 proteins enhance the expression of the oncogenic miR-222 in lung cancer cells. Mol Cell Biochem 2011; 357:363-71. [PMID: 21656127 DOI: 10.1007/s11010-011-0907-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 05/28/2011] [Indexed: 12/18/2022]
Abstract
High-mobility group A1 (HMGA1) is a non-histone chromatin protein that has the ability to regulate the transcriptional activity of many genes. Overexpression of HMGA1 is associated with malignant cellular behavior in a range of human cancers but the underlying mechanism is largely unknown. Here we showed that in a cohort of non-small cell lung cancer (NSCLC) tumors, HMGA1 overexpression was immediately associated with enhanced expression of an oncogenic miRNA, namely, miR-222. Chromatin immunoprecipitation (CHIP) assay revealed that HMGA1 directly binds to the proximal promoter of miR-222 in NSCLC cells. We further showed that HMGA1 silencing reduced miR-222 transcriptional activity, whereas forced HMGA1 expression increased it, indicating that miR-222 is directly regulated by HMGA1. Based on in silico prediction, one of the putative targets of miR-222 is phosphatase 2A subunit B (PPP2R2A) which inhibits Akt phosphorylation (p-Akt). We demonstrated that miR-222 inhibited protein expression of PPP2R2A in NSCLC cells by directly interacting with its 3'-UTR region, leading to an obvious increase of p-Akt. HMGA1 silencing augmented PPP2R2A protein expression and inhibited Akt signaling, resulting in significantly retarded cell growth response to IGF-I. These results suggested that HMGA1 is a positive regulator of miR-222, and HMGA1 overexpression might contribute to dysregulation of Akt signaling in NSCLC.
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Affiliation(s)
- Yunzhi Zhang
- Department of Infectious Disease, Shanghai Public Health Clinical Center Affiliated to Fudan University, Shanghai, People's Republic of China
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