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Mousavi-Niri N, Khakpai F, Moheb-Alian M, Ghanimati E, Abdollah-Pour F, Naseroleslami M. Nano-Stevia reduces the liver injury caused by streptozotocin (STZ)-induced diabetes in rats by targeting PEPCK/GCK genes, INSR pathway and apoptosis. J Diabetes Metab Disord 2023; 22:1519-1529. [PMID: 37975120 PMCID: PMC10638348 DOI: 10.1007/s40200-023-01278-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/02/2023] [Indexed: 11/19/2023]
Abstract
Objectives Extensive application of stevia in the treatment of type 2 diabetes mellitus (DM) has been proven by a large number of previous studies. We prepared stevia loaded in nanoniosomes (nanostevia) to improve its bioavailability, functionality, and stability and explore its protective effects and underlying mechanisms in the liver of STZ-induced diabetic rats. Methods Single-dose intraperitoneal injection of STZ (50 mg/kg body weight) was used to establish diabetic model. The mRNA levels of PEPCK and GCK genes and the protein level of INSR were evaluated by Real time-PCR and Western blot assays, respectively. TUNEL assay was used to detect apoptotic cell death in the liver tissue. Results Diabetic rats exhibited significantly reduced levels of INSR (*** P < 0.001) as well as elevated levels of PEPCK (*** P < 0.001). Both stevia and nano-stevia were capable of increasing levels of GCK and INSR and reducing levels of PEPCK (## P < 0.01 and ### P < 0.001, respectively). In addition, significantly increased number of apoptotic cell death was seen in the liver tissue of diabetic rats (*** P < 0.001) which was markedly mitigated by treatment with both Stevia and nano-Stevia (#P < 0.05 and ## P < 0.01, respectively). Conclusion Both stevia and nano-stevia demonstrates potent anti-apoptotic activity in the liver tissue of diabetic rats by targeting PEPCK/GCK genes and INSR pathway. These finding show that nano-stevia has more potential to reduce the liver injury caused by STZ-induced diabetes in rats and hence can be considered a valid agent and alternative therapy for attenuating complications of type 2 DM. Supplementary Information The online version contains supplementary material available at 10.1007/s40200-023-01278-2.
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Affiliation(s)
- Neda Mousavi-Niri
- Department of Biotechnology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Fatemeh Khakpai
- Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Marzieh Moheb-Alian
- Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Elham Ghanimati
- Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Faezeh Abdollah-Pour
- Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Maryam Naseroleslami
- Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
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Pacifici F, Andreadi A, Arriga R, Pastore D, Capuani B, Bonanni R, Della-Morte D, Bellia A, Lauro D, Donadel G. Omega-3-Enriched Diet Improves Metabolic Profile in Prdx6-Deficient Mice Exposed to Microgravity. Life (Basel) 2023; 13:2245. [PMID: 38137846 PMCID: PMC10744818 DOI: 10.3390/life13122245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/18/2023] [Accepted: 11/20/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND Space travel has always been one of mankind's greatest dreams. Thanks to technological innovation, this dream is becoming more of a reality. Soon, humans (not only astronauts) will travel, live, and work in space. However, a microgravity environment can induce several pathological alterations that should be, at least in part, controlled and alleviated. Among those, glucose homeostasis impairment and insulin resistance occur, which can lead to reduced muscle mass and liver dysfunctions. Thus, it is relevant to shed light on the mechanism underlaying these pathological conditions, also considering a nutritional approach that can mitigate these effects. METHODS To achieve this goal, we used Prdx6-/- mice exposed to Hindlimb Unloading (HU), a well-established experimental protocol to simulate microgravity, fed with a chow diet or an omega-3-enriched diet. RESULTS Our results innovatively demonstrated that HU-induced metabolic alterations, mainly related to glucose metabolism, may be mitigated by the administration of omega-3-enriched diet. Specifically, a significant improvement in insulin resistance has been reported. CONCLUSIONS Although preliminary, our results highlight the importance of specific nutritional approaches that can alleviate microgravity-induced harmful effects. These findings should be considered soon by those planning trips around the earth.
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Affiliation(s)
- Francesca Pacifici
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
| | - Aikaterini Andreadi
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
- Department of Medical Sciences, Fondazione Policlinico Tor Vergata, 00133 Rome, Italy
| | - Roberto Arriga
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
| | - Donatella Pastore
- Department of Human Sciences and Quality of Life Promotion, San Raffaele University, 00166 Rome, Italy;
| | - Barbara Capuani
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
| | - Roberto Bonanni
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy;
| | - David Della-Morte
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
- Department of Human Sciences and Quality of Life Promotion, San Raffaele University, 00166 Rome, Italy;
- Department of Neurology, Evelyn F. McKnight Brain Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
- Interdisciplinary Center for Advanced Studies on Lab-on-Chip and Organ-on-Chip Applications (ICLOC), University of Rome Tor Vergata, 00133 Rome, Italy
| | - Alfonso Bellia
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
- Department of Medical Sciences, Fondazione Policlinico Tor Vergata, 00133 Rome, Italy
| | - Davide Lauro
- Department of Systems Medicine, University of Rome Tor Vergata, 00133 Rome, Italy; (F.P.); (A.A.); (R.A.); (B.C.); (D.D.-M.); (A.B.); (D.L.)
- Department of Medical Sciences, Fondazione Policlinico Tor Vergata, 00133 Rome, Italy
| | - Giulia Donadel
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
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Ikeda H, Mikami R, Yonemochi N, Waddington JL. Regulation of plasma glucose levels by central dopamine D 2 receptors is impaired in type 1 but not type 2 diabetic mouse models. Eur J Pharmacol 2023; 956:175984. [PMID: 37567458 DOI: 10.1016/j.ejphar.2023.175984] [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: 05/24/2023] [Revised: 07/22/2023] [Accepted: 08/09/2023] [Indexed: 08/13/2023]
Abstract
Glucose metabolism is reported to be regulated by the central nervous system, but it is unclear whether this regulation is altered in diabetes. We investigated whether regulation of glucose metabolism by central dopamine D2 receptors is altered in type 1 and type 2 diabetic models. Intracerebroventricular injections of both the dopamine D2 receptor agonist quinpirole and the antagonist l-sulpiride induced hyperglycemia in control mice, but not in streptozotocin (STZ)-induced diabetic mice, a type 1 diabetic model. Hyperglycemia induced by quinpirole or l-sulpiride was diminished following fasting and these drugs did not affect hyperglycemia in the pyruvate tolerance test. In addition, both quinpirole and l-sulpiride increased hepatic glucose-6-phosphatase (G6Pase) mRNA. In STZ-induced diabetic mice, dopamine and dopamine D2 receptor mRNA in the hypothalamus, which regulates glucose homeostasis, were decreased. Hepatic glycogen and G6Pase mRNA were also decreased in STZ-induced diabetic mice. Neither quinpirole nor l-sulpiride increased hepatic G6Pase mRNA in STZ-induced diabetic mice. In diet-induced obesity mice, a type 2 diabetic model, both quinpirole and l-sulpiride induced hyperglycemia, and hypothalamic dopamine and dopamine D2 receptor mRNA were not altered. These results indicate that (i) stimulation or blockade of dopamine D2 receptors causes hyperglycemia by increasing hepatic glycogenolysis, and (ii) stimulation or blockade of dopamine D2 receptors does not affect glucose levels in type 1 but does so in type 2 diabetic models. Moreover, hypothalamic dopaminergic function and hepatic glycogenolysis are decreased in the type 1 diabetic model, which reduces hyperglycemia induced by stimulation or blockade of dopamine D2 receptors.
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Affiliation(s)
- Hiroko Ikeda
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan.
| | - Risa Mikami
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Naomi Yonemochi
- Department of Pathophysiology and Therapeutics, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - John L Waddington
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, 111 St Stephen's Green, Dublin 2, Ireland
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Vulgarin, a Sesquiterpene Lactone from Artemisia judaica, Improves the Antidiabetic Effectiveness of Glibenclamide in Streptozotocin-Induced Diabetic Rats via Modulation of PEPCK and G6Pase Genes Expression. Int J Mol Sci 2022; 23:ijms232415856. [PMID: 36555498 PMCID: PMC9781739 DOI: 10.3390/ijms232415856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022] Open
Abstract
The current investigation assessed the effect of the eudesmanolid, Vulgarin (VGN), obtained from Artemisia judaica (A. judaica), on the antidiabetic potential of glibenclamide (GLB) using streptozotocin (STZ) to induce diabetes. Seven groups of rats were used in the study; the first group received the vehicle and served as normal control. The diabetic rats of the second to the fifth groups were treated with the vehicle (negative control), GLB at 5 mg/kg (positive control), VGN at 10 mg/kg (VGN-10) and VGN at 20 mg/kg (VGN-20), respectively. The diabetic rats of the sixth and seventh groups were administered combinations of GLB plus VGN-10 and GLB plus VGN-20, respectively. The diabetic rats treated with GLB plus VGN-20 combination showed marked improvement in the fasting blood glucose (FBG), insulin and glycated hemoglobin (HbA1c), as well as the lipid profile, compared with those treated with GLB alone. Further, the pancreatic tissues of the diabetic rats that received the GLB+VGN-20 combination showed superior improvements in lipid peroxidation and antioxidant parameters than those of GLB monotherapy. The insulin content of the β-cells was restored in all treatments, while the levels of glucagon and somatostatin of the α- and δ-endocrine cells were reduced in the pancreatic islets. In addition, the concurrent administration of GLB+VGN-20 was the most effective in restoring PEPCK and G6Pase mRNA expression in the liver. In conclusion, the results demonstrated that the GLB+VGN-20 combination led to greater glycemic improvement in diabetic rats compared with GLB monotherapy through its antioxidant effect and capability to modulate PEPCK and G6Pase gene expression in their livers.
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Kaushik A, Sangtani R, Parmar HS, Bala K. Algal metabolites: Paving the way towards new generation antidiabetic therapeutics. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Fan C, Liu Y, Wang Y, Zhang A, Xie W, Zhang H, Weng Q, Xu M. Expression of glycogenic genes in the oviduct of Chinese brown frog (Rana dybowskii) during pre-brumation. Theriogenology 2022; 185:78-87. [DOI: 10.1016/j.theriogenology.2022.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
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Roy P, Saha S, Chakraborty J. Looking into the possibilities of cure of the type 2 diabetes mellitus by nanoparticle-based RNAi and CRISPR-Cas9 system: A review. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102830] [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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Jiang Y, Zhang N, Zhou Y, Zhou Z, Bai Y, Strappe P, Blanchard C. Manipulations of glucose/lipid metabolism and gut microbiota of resistant starch encapsulated Ganoderma lucidum spores in T2DM rats. Food Sci Biotechnol 2021; 30:755-764. [PMID: 34123471 PMCID: PMC8144259 DOI: 10.1007/s10068-021-00908-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 02/27/2021] [Accepted: 03/27/2021] [Indexed: 12/12/2022] Open
Abstract
Our team previously demonstrated that Ganoderma lucidum spores (GLS) and resistant starch (RS) had hypoglycemic effects separately on type 2 diabetic mellitus (T2DM) rats. This work was to explore the effects of administering encapsulated GLS within RS (referred to as EGLS) in the T2DM rats, which were induced by streptozotocin (STZ). The EGLS was orally administered to rats for 28 days. The parameters of glycometabolism and lipometabolism were evaluated, and fecal microbiota composition was investigated. The results showed that EGLS significantly enhanced glycometabolism and lipometabolism parameters in T2DM rats, which might be associate with the enhancement of the glucose and lipid metabolism, insulin secretion, and glycogen synthesis and reduced lipogenesis. Furthermore, the intervention of EGLS also reduced the Proteobacteria community and improved dysfunctional gut microbiota. This study indicated EGLS may be a potential candidate for dietary intervention to modulate diabetes.
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Affiliation(s)
- Yumei Jiang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin International Joint Academy of Biomedicine, Tianjin, 300457 China
- College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457 China
| | - Na Zhang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin International Joint Academy of Biomedicine, Tianjin, 300457 China
| | - Yawen Zhou
- College of Food Science and Technology, Nanjing Agriculture University, Nanjing, 210095 China
| | - Zhongkai Zhou
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin International Joint Academy of Biomedicine, Tianjin, 300457 China
- ARC Functional Grains Centre, Charles Sturt University, Wagga Wagga, NSW 2678 Australia
| | - Yu Bai
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin International Joint Academy of Biomedicine, Tianjin, 300457 China
| | - Padraig Strappe
- ARC Functional Grains Centre, Charles Sturt University, Wagga Wagga, NSW 2678 Australia
| | - Chris Blanchard
- ARC Functional Grains Centre, Charles Sturt University, Wagga Wagga, NSW 2678 Australia
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Lambrechts IA, Lall N. Traditional usage and biological activity of Plectranthus madagascariensis and its varieties: A review. JOURNAL OF ETHNOPHARMACOLOGY 2021; 269:113663. [PMID: 33278544 DOI: 10.1016/j.jep.2020.113663] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/28/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Plectranthus madagascariensis (Pers.) Benth. is an indigenous aromatic South African plant species that are traditionally used to treat various dermatological and respiratory ailments. AIM OF THE STUDY Three varieties of P. madagascariensis exist in South Africa, namely, Plectranthus aliciae (Codd) van Jaarsv. & T.J. Edwards, Plectranthus ramosior (Benth.) Van Jaarsv. and Plectranthus madagascariensis (Pers.) Benth var. madagascariensis. This article summarizes the documented ethnobotanical uses and research which has been conducted to date on the chemical constituents and biological effects of P. madagascariensis and its varieties. This review aimed to investigate and highlight the lack scientific reports of the potential activity of these varieties based on their traditional usage and to emphasise the need for further investigation of the benefits of P. madagascariensis and its varieties. MATERIALS AND METHODS Extensive database retrieval using platforms not limited to but including Google Scholar, ScienceDirect and PubMed, was performed by using keywords such as "Plectranthus madagascariensis" "Plectranthus madagascariensis var. aliciae", "Plectranthus aliciae", "Plectranthus ramosior", "Plectranthus madagascariensis var. ramosior" and "Plectranthus hirtus" In addition, relevant books and digital documentation were consulted to collect all available scientific literature to provide a comprehensive review. RESULTS Several studies have reported the traditional usage of P. madagascariensis for the treatment of diseases related to the respiratory system such as coughs, colds and asthma as well as dermatological disorders associated with wounds and inflammation. Whilst there are no reports on the traditional usage of P. madagascariensis varieties to treat other maladies, several other species within the genus are used in other traditional practices. Plectranthus ramosior is used as a toxin for fishing. In literature, seven major phytochemical compounds have been identified from P. madagascariensis. Its extract and essential oil contain polyphenols, abietane diterpenes and abietane diterpenes with a quinone moiety. The extracts and major chemical constituents of P. madagascariensis and its major phytochemicals have reported activity against several biological targets. Reports relating to the antibacterial activity of P. madagascariensis against microbes associated with tuberculosis and wound infections has been consistent and correlates with the documented traditional usage of the plant. Literature reported on the antibacterial activity of P. aliciae targeting bacteria associated with wound infections and lung cancer cells. No further literature reports of the biological activity of the other P. madagascariensis varieties have been found. Other noteworthy biological activities reported in the literature of P. madagascariensis and its compounds include their activities against targets of Alzheimer's disease and breast cancer, in particular. This activity is not related to the traditional usage of the plant. CONCLUSION Plectranthus madagascariensis and its compounds have been proven to be effective in treating a range of maladies. Based on the extensive literature on this plant, it can be concluded that numerous in vitro pharmacological activities of P. madagascariensis have been reported. However, there is a lack of information available for this species with regards to its in vivo data including both pre-clinical and clinical studies. Since the extract of P. madagascariensis and its isolated compounds have displayed noteworthy anticancer potential, we recommend further investigation of pharmacokinetic studies to be included in future research.
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Affiliation(s)
- Isa Anina Lambrechts
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa.
| | - Namrita Lall
- Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa; School of Natural Resources, University of Missouri, Columbia, MO, United States; College of Pharmacy, JSS Academy of Higher Education and Research, India.
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Montrose K, López Cabezas RM, Paukštytė J, Saarikangas J. Winter is coming: Regulation of cellular metabolism by enzyme polymerization in dormancy and disease. Exp Cell Res 2020; 397:112383. [PMID: 33212148 DOI: 10.1016/j.yexcr.2020.112383] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/12/2020] [Accepted: 11/14/2020] [Indexed: 12/20/2022]
Abstract
Metabolism feeds growth. Accordingly, metabolism is regulated by nutrient-sensing pathways that converge growth promoting signals into biosynthesis by regulating the activity of metabolic enzymes. When the environment does not support growth, organisms invest in survival. For cells, this entails transitioning into a dormant, quiescent state (G0). In dormancy, the activity of biosynthetic pathways is dampened, and catabolic metabolism and stress tolerance pathways are activated. Recent work in yeast has demonstrated that dormancy is associated with alterations in the physicochemical properties of the cytoplasm, including changes in pH, viscosity and macromolecular crowding. Accompanying these changes, numerous metabolic enzymes transition from soluble to polymerized assemblies. These large-scale self-assemblies are dynamic and depolymerize when cells resume growth. Here we review how enzyme polymerization enables metabolic plasticity by tuning carbohydrate, nucleic acid, amino acid and lipid metabolic pathways, with particular focus on its potential adaptive value in cellular dormancy.
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Affiliation(s)
- Kristopher Montrose
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Rosa María López Cabezas
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Jurgita Paukštytė
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Juha Saarikangas
- Helsinki Institute of Life Science, HiLIFE, University of Helsinki, Finland; Research Programme in Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Finland; Neuroscience Center, University of Helsinki, Finland.
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Gong H, Gao J, Wang Y, Luo Q, Guo K, Ren F, Mao X. Identification of novel peptides from goat milk casein that ameliorate high-glucose-induced insulin resistance in HepG2 cells. J Dairy Sci 2020; 103:4907-4918. [DOI: 10.3168/jds.2019-17513] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 02/04/2020] [Indexed: 12/21/2022]
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Kinetic and structural analysis of Escherichia coli phosphoenolpyruvate carboxykinase mutants. Biochim Biophys Acta Gen Subj 2020; 1864:129517. [DOI: 10.1016/j.bbagen.2020.129517] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/07/2019] [Accepted: 01/02/2020] [Indexed: 11/16/2022]
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Montal ED, Bhalla K, Dewi RE, Ruiz CF, Haley JA, Ropell AE, Gordon C, Haley JD, Girnun GD. Inhibition of phosphoenolpyruvate carboxykinase blocks lactate utilization and impairs tumor growth in colorectal cancer. Cancer Metab 2019; 7:8. [PMID: 31388420 PMCID: PMC6670241 DOI: 10.1186/s40170-019-0199-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/13/2019] [Indexed: 11/10/2022] Open
Abstract
Background Metabolic reprogramming is a key feature of malignant cells. While glucose is one of the primary substrates for malignant cells, cancer cells also display a remarkable metabolic flexibility. Depending on nutrient availability and requirements, cancer cells will utilize alternative fuel sources to maintain the TCA cycle for bioenergetic and biosynthetic requirements. Lactate was typically viewed as a passive byproduct of cancer cells. However, studies now show that lactate is an important substrate for the TCA cycle in breast, lung, and pancreatic cancer. Methods Metabolic analysis of colorectal cancer (CRC) cells was performed using a combination of bioenergetic analysis and 13C stable isotope tracing. Results We show here that CRC cells use lactate to fuel the TCA cycle and promote growth especially under nutrient-deprived conditions. This was mediated in part by maintaining cellular bioenergetics. Therefore targeting the ability of cancer cells to utilize lactate via the TCA cycle would have a significant therapeutic benefit. Phosphoenolpyruvate carboxykinase (PEPCK) is an important cataplerotic enzyme that promotes TCA cycle activity in CRC cells. Treatment of CRC cells with low micromolar doses of a PEPCK inhibitor (PEPCKi) developed for diabetes decreased cell proliferation and utilization of lactate by the TCA cycle in vitro and in vivo. Mechanistically, we observed that the PEPCKi increased nutrient stress as determined by decreased cellular bioenergetics including decreased respiration, ATP levels, and increased AMPK activation. 13C stable isotope tracing showed that the PEPCKi decreased the incorporation of lactate into the TCA cycle. Conclusions These studies highlight lactate as an important substrate for CRC and the use of PEPCKi as a therapeutic approach to target lactate utilization in CRC cells.
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Affiliation(s)
- Emily D Montal
- 1Department of Pharmacological Sciences, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY 11794 USA.,2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA
| | - Kavita Bhalla
- 3Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, 22 S Greene St, Baltimore, MD 21201 USA
| | - Ruby E Dewi
- 4Stanford University, 450 Serra Mall, Stanford, CA 94305 USA
| | - Christian F Ruiz
- 2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA
| | - John A Haley
- 2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA
| | - Ashley E Ropell
- 2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA
| | - Chris Gordon
- 2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA
| | - John D Haley
- 2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA
| | - Geoffrey D Girnun
- 1Department of Pharmacological Sciences, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY 11794 USA.,2Department of Pathology, Stony Brook University School of Medicine, 100 Nicolls Rd, Stony Brook, NY 11794 USA.,5Department of Pathology, Stony Brook University, 101 Nicolls Rd, BST Level 9, Room 191, Stony Brook, NY 11794 USA
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Westermeier F, Holyoak T, Asenjo JL, Gatica R, Nualart F, Burbulis I, Bertinat R. Gluconeogenic Enzymes in β-Cells: Pharmacological Targets for Improving Insulin Secretion. Trends Endocrinol Metab 2019; 30:520-531. [PMID: 31213347 DOI: 10.1016/j.tem.2019.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 02/06/2023]
Abstract
Pancreatic β-cells express the gluconeogenic enzymes glucose 6-phosphatase (G6Pase), fructose 1,6-bisphosphatase (FBP), and phosphoenolpyruvate (PEP) carboxykinase (PCK), which modulate glucose-stimulated insulin secretion (GSIS) through their ability to reverse otherwise irreversible glycolytic steps. Here, we review current knowledge about the expression and regulation of these enzymes in the context of manipulating them to improve insulin secretion in diabetics. Because the regulation of gluconeogenic enzymes in β-cells is so poorly understood, we propose novel research avenues to study these enzymes as modulators of insulin secretion and β-cell dysfunction, with especial attention to FBP, which constitutes an attractive target with an inhibitor under clinical evaluation at present.
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Affiliation(s)
- Francisco Westermeier
- FH JOANNEUM Gesellschaft mbH University of Applied Sciences, Institute of Biomedical Science, Eggenberger Allee 13, 8020 Graz, Austria
| | - Todd Holyoak
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Joel L Asenjo
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Independencia 631, 5110566 Valdivia, Chile
| | - Rodrigo Gatica
- Escuela de Veterinaria, Facultad de Ciencias, Universidad Mayor, La Pirámide 5750, 8580745 Santiago, Chile
| | - Francisco Nualart
- Centro de Microscopía Avanzada, CMA BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160 C, 4030000 Concepción, Chile
| | - Ian Burbulis
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Virginia, Jordan Hall Room 6022, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA; Escuela de Medicina, Universidad San Sebastián, Sede Patagonia, Lago Panguipulli 1390, 5501842 Puerto Montt, Chile
| | - Romina Bertinat
- Centro de Microscopía Avanzada, CMA BIO, Facultad de Ciencias Biológicas, Universidad de Concepción, Casilla 160 C, 4030000 Concepción, Chile.
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Chai BK, Al-Shagga M, Pan Y, Then SM, Ting KN, Loh HS, Mohankumar SK. Cis-9, Trans-11 Conjugated Linoleic Acid Reduces Phosphoenolpyruvate Carboxykinase Expression and Hepatic Glucose Production in HepG2 Cells. Lipids 2019; 54:369-379. [PMID: 31124166 DOI: 10.1002/lipd.12154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 11/08/2022]
Abstract
Dysregulated hepatic gluconeogenesis is a hallmark of insulin resistance and type 2 diabetes mellitus (T2DM). Although existing drugs have been proven to improve gluconeogenesis, achieving this objective with functional food is of interest, especially using conjugated linoleic acid (CLA) found in dairy products. Both cis-9, trans-11 (c9,t11) and trans-10, cis-12 (t10,c12) isomers of CLA were tested in human (HepG2) and rat (H4IIE) hepatocytes for their potential effects on gluconeogenesis. The hepatocytes exposed for 24 h with 20 μM of c9,t11-CLA had attenuated the gluconeogenesis in both HepG2 and H4IIE by 62.5% and 80.1%, respectively. In contrast, t10,c12-CLA had no effect. Of note, in HepG2 cells, the exposure of c9,t11-CLA decreased the transcription of gluconeogenic enzymes, cytosolic phosphoenolpyruvate carboxykinase (PCK1) by 87.7%, and glucose-6-phosphatase catalytic subunit (G6PC) by 38.0%, while t10,c12-CLA increased the expression of G6PC, suggesting the isomer-specific effects of CLA on hepatic glucose production. In HepG2, the peroxisome proliferator-activated receptor (PPAR) agonist, rosiglitazone, reduced the glucose production by 72.9%. However, co-administration of c9,t11-CLA and rosiglitazone neither exacerbated nor attenuated the efficacy of rosiglitazone to inhibit glucose production; meanwhile, t10,c12-CLA abrogated the efficacy of rosiglitazone. Paradoxically, PPARγ antagonist GW 9662 also led to 70.2% reduction of glucose production and near undetectable PCK1 expression by abrogating CLA actions. Together, while the precise mechanisms by which CLA isomers modulate hepatic gluconeogenesis directly or via PPAR warrant further investigation, our findings establish that c9,t11-CLA suppresses gluconeogenesis by decreasing PEPCK on hepatocytes.
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Affiliation(s)
- Boon Kheng Chai
- Department of Biomedical Sciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Mustafa Al-Shagga
- Department of Biomedical Sciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Yan Pan
- Department of Biomedical Sciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Sue-Mian Then
- Department of Biomedical Sciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Kang Nee Ting
- Department of Biomedical Sciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Hwei-San Loh
- School of Biosciences, Faculty of Science, University of Nottingham Malaysia Campus, Jalan Broga, 43500, Semenyih, Selangor Darul Ehsan, Malaysia
| | - Suresh K Mohankumar
- TIFAC CORE in Herbal Drugs, Department of Pharmacognosy, JSS College of Pharmacy (Ooty), JSS Academy of Higher Education & Research, Rocklands, Udhagamandalam, 643001, Tamil Nadu, India
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16
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Sabir S, Akash MSH, Fiayyaz F, Saleem U, Mehmood MH, Rehman K. Role of cadmium and arsenic as endocrine disruptors in the metabolism of carbohydrates: Inserting the association into perspectives. Biomed Pharmacother 2019; 114:108802. [PMID: 30921704 DOI: 10.1016/j.biopha.2019.108802] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/13/2019] [Accepted: 03/19/2019] [Indexed: 12/11/2022] Open
Abstract
Endocrine disrupting chemicals (EDCs) have widespread environmental distribution originated from both natural and anthropogenic sources. From the last few decades, their contamination has been raised dramatically owing to continuous discharge in sewage and untreated industrial effluents. They have rapidly gained a considerable attention due to their critical role in the development of multiple endocrine-related disorders notably diabetes mellitus (DM). Cadmium and arsenic, among the most hazardous EDCs, are not only widely spread in our environment, but they are also found to be associated with wide range of health hazards. After entering into the human body, they are preferably accumulated in the liver, kidney and pancreas where they exhibit deleterious effects on carbohydrate metabolism pathways notably glycolysis, glucogenesis and gluconeogenesis through the modification and impairment of relevant key enzymes activity. Impairment of hepatic glucose homeostasis plays a crucial role in the pathogenesis of DM. Along with compromised function of pancreas and muscles, diminished liver and kidney functions also contribute considerably to increase the blood glucose level. These metals have potential to bring conformational changes in these enzymes and make them inactive. Additionally, these metals also disturb the hormonal balance, such as insulin, glucocorticoids and catecholamines; by damaging pancreas and adrenal gland, respectively. Moreover, these metals also enhance the production of reactive oxygen species and depress the anti-oxidative defense mechanism with subsequent disruption of multiple organs. In this article, we have briefly highlighted the impact of arsenic and cadmium on the metabolism of carbohydrates and the enzymes that are involved in carbohydrate metabolism and glucose homeostasis.
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Affiliation(s)
- Shakila Sabir
- Department of Pharmaceutical Chemistry, Government College University Faisalabad, Pakistan; Department of Pharmacology, Government College University Faisalabad, Pakistan
| | | | - Fareeha Fiayyaz
- Department of Pharmaceutical Chemistry, Government College University Faisalabad, Pakistan; Department of Microbiology, Government College University Faisalabad, Pakistan
| | - Uzma Saleem
- Department of Pharmacology, Government College University Faisalabad, Pakistan
| | | | - Kanwal Rehman
- Institute of Pharmacy, Physiology and Pharmacy, University of Agriculture, Faisalabad, Pakistan.
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Kulabas SS, Ipek H, Tufekci AR, Arslan S, Demirtas I, Ekren R, Sezerman U, Tumer TB. Ameliorative potential of Lavandula stoechas in metabolic syndrome via multitarget interactions. JOURNAL OF ETHNOPHARMACOLOGY 2018; 223:88-98. [PMID: 29729383 DOI: 10.1016/j.jep.2018.04.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 04/19/2018] [Accepted: 04/28/2018] [Indexed: 06/08/2023]
Abstract
ETHNOPHARMACOLOGICAL IMPORTANCE Decoction and infusion prepared from aerial parts of Lavandula stoechas L. (L. stoechas) have been traditionally used as remedy against several components of metabolic syndrome (MetS) and associated disorders including type II diabetes and cardiovascular diseases by Anatolian people. AIM OF THE STUDY The aim is to elucidate the potential ameliorative effects of L. stoechas aqueous extracts on insulin resistance and inflammation models through multitarget in vitro approaches and also to elucidate mechanism of action by analyzing transcriptional and metabolic responses. MATERIALS AND METHODS An aqueous extract was prepared and fractionated to give rise to ethyl acetate (EE) and butanol (BE) extracts. The anti-insulin resistance effects of BE and EE were evaluated on palmitate induced insulin resistance model of H4IIE, C2C12 and 3T3L1 cells by using several metabolic parameters. Specifically, whole genome transcriptome analysis was performed by using microarray over 55.000 genes in control, insulin resistant and EE (25 µg/mL) treated insulin resistant H4IIE cells. Anti-inflammatory effects of both extracts were analyzed in LPS-stimulated RAW264.7 macrophages. RESULTS Both EE and BE at low doses (25-50 µg/mL) significantly decreased hepatic gluconeogenesis in H4IIE cell line by suppressing the expression of PEPCK and G6Pase. In C2C12 myotubes, both extracts increased the insulin stimulated glucose uptake more effectively than metformin. Both extracts decreased the isoproterenol induced lipolysis in 3T3L1 cell line. Moreover, they also effectively increased the expression of lipoprotein lipase protein level in insulin resistant myotubes at low doses. EE increased the protein level of PPARγ and stimulated the activation AKT in insulin resistant H4IIE and C2C12 cell lines. The results obtained from biochemical assays, mRNA/protein studies and whole genome transcriptome analyses were found to be complementary and provided support for the hypothesis that EE might be biologically active against insulin resistance and act through the inhibition of liver gluconeogenesis and AKT activation. Besides, LPS induced inflammation in RAW264.7 macrophages was mainly inhibited by EE through suppression of iNOS/NO signaling, IL1β and COX-2 genes. HPLC-TOF/MS analysis of EE of L. stoechas mainly resulted in caffeic acid, apigenin, luteolin, rosmarinic acid and its methyl ester, 4-hydroxybenzoic acid, vanillic acid, ferrulic acid and salicylic acid. CONCLUSION Data suggest that EE of L. stoechas contains phytochemicals that can be effective in the treatment/prevention of insulin resistance and inflammation. These results validate the traditional use of L. stoechas in Anatolia against several metabolic disorders including metabolic syndrome.
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Affiliation(s)
- S S Kulabas
- Graduate Program of Biology, Institute of Natural and Applied Sciences, Çanakkale Onsekiz Mart University, 17100 Çanakkale, Turkey
| | - H Ipek
- Graduate Program of Bioengineering, Institute of Natural and Applied Sciences, Çanakkale Onsekiz Mart University, 17100 Çanakkale, Turkey
| | - A R Tufekci
- Department of Chemistry, Faculty of Sciences, Çankırı Karatekin University 18200 Çankırı Turkey
| | - S Arslan
- Department of Biology, Faculty of Art and Science, Pamukkale University, 20160 Denizli, Turkey
| | - I Demirtas
- Department of Chemistry, Faculty of Sciences, Çankırı Karatekin University 18200 Çankırı Turkey
| | - R Ekren
- Graduate Program of Medical Biotechnology, Institute of Health Sciences, Acıbadem Mehmet Ali Aydınlar University, 34752 İstanbul, Turkey
| | - U Sezerman
- Department of Biostatistics and Medical Informatics, Institute of Health Sciences, Acıbadem Mehmet Ali Aydınlar University, 34752 İstanbul, Turkey
| | - T B Tumer
- Department of Molecular Biology and Genetics, Faculty of Art and Science, Çanakkale Onsekiz Mart University, 17100 Çanakkale, Turkey.
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18
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Wu S, Li N, Yang C, Yan L, Liang X, Ren M, Yang L. Synthesis of cationic branched tea polysaccharide derivatives for targeted delivery of siRNA to hepatocytes. Int J Biol Macromol 2018; 118:808-815. [PMID: 29857104 DOI: 10.1016/j.ijbiomac.2018.05.221] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 05/20/2018] [Accepted: 05/28/2018] [Indexed: 01/01/2023]
Abstract
The cationic branched tea polysaccharide (CTPSA) derivative bearing N-acylurea and 3-(dimethylamino)-1-propylamine residues was synthesized and characterized using FTIR and 1H NMR spectroscopy. A nonspecific siRNA (NsiRNA) was used as a model molecule of functional siRNA that could downregulate over-expressed glycometabolism enzymes in the liver. The result from the agarose gel electrophoresis confirmed that the CTPSA and NsiRNA could form stable complexes when their weight ratio was larger than 18. The zeta potentials and sizes of the complexes were in the range of +8-+15 mv and 120-150 nm, respectively. The CTPSA/NsiRNA complex was observed as nanoparticles with a spherical shape of approximately 100 nm using scanning electron microscopy. The CTPSA derivative and the CTPSA/NsiRNA complexes exhibited lower cytotoxicity in HL-7702 cells when compared with the branched PEI (bPEI) and bPEI/NsiRNA complexes assessed by the Cell Counting Kit-8 assay. The results of flow cytometric analysis and laser confocal microscopy indicated that the CTPSA derivative could effectively target the transfer of the NsiRNA to HL-7702 cells. This work provides a potential approach to promote the CTPSA derivative as a nonviral vector for targeted delivery of functional siRNA to hepatocytes.
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Affiliation(s)
- Shuyun Wu
- Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-based Composites, Sun Yat-Sen University, Guangzhou 510275, China
| | - Na Li
- Department of Endocrinology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Chuan Yang
- Department of Endocrinology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Li Yan
- Department of Endocrinology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China
| | - Xuan Liang
- Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-based Composites, Sun Yat-Sen University, Guangzhou 510275, China
| | - Meng Ren
- Department of Endocrinology, Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China.
| | - Liqun Yang
- Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-based Composites, Sun Yat-Sen University, Guangzhou 510275, China.
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19
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Lin X, Shi H, Cui Y, Wang X, Zhang J, Yu W, Wei M. Dendrobium mixture regulates hepatic gluconeogenesis in diabetic rats via the phosphoinositide-3-kinase/protein kinase B signaling pathway. Exp Ther Med 2018; 16:204-212. [PMID: 29896241 PMCID: PMC5995077 DOI: 10.3892/etm.2018.6194] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 01/22/2018] [Indexed: 01/07/2023] Open
Abstract
The present study aimed to evaluate the impact of dendrobium mixture (DMix) on the gene and protein expression of insulin signaling pathway-associated factors in the livers of diabetic rats. The molecular mechanisms by which DMix inhibits gluconeogenesis were also investigated. A total of 47 female Wistar rats were used in the present study. Of these, 11 rats were randomly selected as healthy controls and diabetes was induced in the remaining 36 rats by administering a high-fat and high-sugar diet for 6 weeks, followed by two intraperitoneal injections of streptozotocin. The 36 rats were screened for diabetes and then randomly divided into three groups: Model, metformin and DMix groups. Following 12 weeks of treatment, the fasting blood glucose (FBG), glycosylated serum protein (GSP), serum insulin, blood lipids [total cholesterol (Tch) and triglycerides (TG)], alanine transaminase (ALT) and aspartate transaminase (AST) were assessed. In addition, hematoxylin and eosin staining was used for histomorphological examination of the liver tissues. The mRNA expression of insulin receptor (InsR), forkhead box protein O1 (FoxO1), phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase) in the liver was measured with reverse transcription-quantitative polymerase chain reaction and the protein expression of InsR, phosphoinositide-3-kinase (PI3K), phosphorylated (p)-PI3K, protein kinase B (Akt), p-Akt, FoxO1, PEPCK and G6Pase in the liver was measured by western blot analysis. The FBG, GSP, InsR, Tch, TG, ALT and AST levels were significantly lower in the DMix-treated group compared with the model group (P<0.05). In addition, DMix treatment notably improved liver histopathology and significantly increased the gene and protein expression of InsR, PI3K and Akt (P<0.05). DMix treatment also significantly reduced the gene and protein expression of FoxO1, PEPCK and G6Pase (P<0.05). DMix effectively reduced FBG and blood lipids and significantly improved liver function and insulin resistance in diabetic rats, possibly by regulating the gene and protein expression of molecules associated with the PI3K/Akt signaling pathway.
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Affiliation(s)
- Xinjun Lin
- Institute of Integrated Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Hong Shi
- Institute of Integrated Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Yi Cui
- Department of Ophthalmology, Fujian Medical University Union Hospital, Fuzhou, Fujian 350001, P.R. China
| | - Xiaoning Wang
- Institute of Integrated Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Jieping Zhang
- Institute of Integrated Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Wenzhen Yu
- Institute of Integrated Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
| | - Min Wei
- Institute of Integrated Chinese and Western Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China
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Kerru N, Singh-Pillay A, Awolade P, Singh P. Current anti-diabetic agents and their molecular targets: A review. Eur J Med Chem 2018; 152:436-488. [PMID: 29751237 DOI: 10.1016/j.ejmech.2018.04.061] [Citation(s) in RCA: 185] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 04/17/2018] [Accepted: 04/30/2018] [Indexed: 12/22/2022]
Abstract
Diabetes mellitus is a medical condition characterized by the body's loss of control over blood sugar. The frequency of diagnosed cases and consequential increases in medical costs makes it a rapidly growing chronic disease that threatens human health worldwide. In addition, its unnerving statistical projections are perilous to both the economy of the nation and man's life expectancy. Type-I and type-II diabetes are the two clinical forms of diabetes mellitus. Type-II diabetes mellitus (T2DM) is illustrated by the abnormality of glucose homeostasis in the body, resulting in hyperglycemia. Although significant research attention has been devoted to the development of diabetes regimens, which demonstrates success in lowering blood glucose levels, their efficacies are unsustainable due to undesirable side effects such as weight gain and hypoglycemia. Over the years, heterocyclic scaffolds have been the basis of anti-diabetic chemotherapies; hence, in this review we consolidate the use of bioactive scaffolds, which have been evaluated for their biological response as inhibitors against their respective anti-diabetic molecular targets over the past five years (2012-2017). Our investigation reveals a diverse target set which includes; protein tyrosine phosphatase 1 B (PTP1B), dipeptidly peptidase-4 (DPP-4), free fatty acid receptors 1 (FFAR1), G protein-coupled receptors (GPCR), peroxisome proliferator activated receptor-γ (PPARγ), sodium glucose co-transporter-2 (SGLT2), α-glucosidase, aldose reductase, glycogen phosphorylase (GP), fructose-1,6-bisphosphatase (FBPase), glucagon receptor (GCGr) and phosphoenolpyruvate carboxykinase (PEPCK). This review offers a medium on which future drug design and development toward diabetes management may be modelled (i.e. optimization via structural derivatization), as many of the drug candidates highlighted show promise as an effective anti-diabetic chemotherapy.
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Affiliation(s)
- Nagaraju Kerru
- School of Chemistry and Physics, University of KwaZulu-Natal, P/Bag X54001, Westville, Durban, South Africa
| | - Ashona Singh-Pillay
- School of Chemistry and Physics, University of KwaZulu-Natal, P/Bag X54001, Westville, Durban, South Africa.
| | - Paul Awolade
- School of Chemistry and Physics, University of KwaZulu-Natal, P/Bag X54001, Westville, Durban, South Africa
| | - Parvesh Singh
- School of Chemistry and Physics, University of KwaZulu-Natal, P/Bag X54001, Westville, Durban, South Africa.
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21
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Sun H, Zuo X, Sun L, Yan P, Zhang F, Xue H, Li E, Zhou Y, Wu R, Wu X. Insights into the seasonal adaptive mechanisms of Chinese alligators (Alligator sinensis) from transcriptomic analyses. AUST J ZOOL 2018. [DOI: 10.1071/zo18005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The Chinese alligator (Alligator sinensis) is an endemic and rare species in China, and is considered to be one of the most endangered vertebrates in the world. It is known to hibernate, an energy-saving strategy against cold temperatures and food deprivation. Changes in gene expression during hibernation remain largely unknown. To understand these complex seasonal adaptive mechanisms, we performed a comprehensive survey of differential gene expression in heart, skeletal muscle, and kidney of hibernating and active Chinese alligators using RNA-Sequencing. In total, we identified 4780 genes differentially expressed between the active and hibernating periods. GO and KEGG pathway analysis indicated the likely role of these differentially expressed genes (DEGs). The upregulated DEGs in the active Chinese alligator, CSRP3, MYG and PCKGC, may maintain heart and skeletal muscle contraction, transport and storage of oxygen, and enhance the body’s metabolism, respectively. The upregulated DEGs in the dormant Chinese alligator, ADIPO, CIRBP and TMM27, may improve insulin sensitivity and glucose/lipid metabolism, protect cells against harmful effects of cold temperature and hypoxia, regulate amino acid transport and uptake, and stimulate the proliferation of islet cells and the secretion of insulin. These results provide a foundation for understanding the molecular mechanisms of the seasonal adaptation required for hibernation in Chinese alligators, as well as effective information for other non-model organisms research.
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22
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Dkhar B, Khongsti K, Thabah D, Syiem D, Satyamoorthy K, Das B. Genistein represses PEPCK-C expression in an insulin-independent manner in HepG2 cells and in alloxan-induced diabetic mice. J Cell Biochem 2017; 119:1953-1970. [PMID: 28816409 DOI: 10.1002/jcb.26356] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 08/15/2017] [Indexed: 12/14/2022]
Abstract
Genistein has been reported to exert beneficial effects on type 2 diabetes mellitus (T2DM); however, the underlying molecular mechanisms involved therein have not been clearly elucidated. To address this question, the effect of genistein on the expression of phosphoenolpyruvate carboxykinase (PEPCK), and glucose production in HepG2 cells and in alloxan-induced diabetic mice was investigated. HepG2 cells were exposed to different concentration of genistein in presence or absence of modulators, and the expression of cytosolic PEPCK (PEPCK-C) and the signaling pathways was studied. Further, the biological relevance of the in vitro study was tested in alloxan-induced diabetic mice. Genistein lowered PEPCK-C expression and glucose production in HepG2 cells accompanied with increased in phosphorylation states of AMPK, MEK½, ERK½, and CRTC2. Treatment with the AMPK inhibitor (compound C) enhanced genistein-induced MEK½ and ERK½ activity indicating a potential cross-talk between the two signaling pathways. In vivo, genistein also reduced fasting glucose levels accompanied with reduced PEPCK-C expression and increased in AMPK and ERK½ phosphorylation states in the liver of genistein-treated alloxan-induced diabetic mice. Genistein fulfills the criteria of a suitable anti-diabetic agent by reducing glucose production and inhibiting PEPCK-C expression in HepG2 cells and also in alloxan-induced diabetic mice. These results indicate that genistein is an effective candidate for preventing T2DM through the modulation of AMPK-CRTC2 and MEK/ERK signaling pathways, which may allow a novel approach to modulate dysfunction in hepatic gluconeogenesis in T2DM.
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Affiliation(s)
- Barilin Dkhar
- Department of Zoology, North-Eastern Hill University, Shillong, India
| | | | - Daiahun Thabah
- Department of Biochemistry, North-Eastern Hill University, Shillong, India
| | - Donkupar Syiem
- Department of Biochemistry, North-Eastern Hill University, Shillong, India
| | - Kapaettu Satyamoorthy
- Department of Biotechnology, School of Life Sciences, Manipal University, Manipal, Karnataka, India
| | - Bidyadhar Das
- Department of Zoology, North-Eastern Hill University, Shillong, India
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23
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Tang W, Li S, Liu Y, Wu JC, Pan MH, Huang MT, Ho CT. Anti-diabetic activities ofcis- andtrans-2,3,5,4′-tetrahydroxystilbene 2-O-β-glucopyranoside fromPolygonum multiflorum. Mol Nutr Food Res 2017; 61. [DOI: 10.1002/mnfr.201600871] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/25/2016] [Accepted: 12/30/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Wenping Tang
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains; Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization; College of Life Science; Huanggang Normal University; Huanggang China
- Department of Food Science; Rutgers-The State University of New Jersey; New Brunswick NJ USA
| | - Shiming Li
- Hubei Collaborative Innovation Center for the Characteristic Resources Exploitation of Dabie Mountains; Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization; College of Life Science; Huanggang Normal University; Huanggang China
| | - Yue Liu
- Department of Chemical Biology; Rutgers-The State University of New Jersey; Piscataway NJ USA
| | - Jia-Ching Wu
- Institute of Food Science and Technology; National Taiwan University; Taipei Taiwan
| | - Min-Hsiung Pan
- Institute of Food Science and Technology; National Taiwan University; Taipei Taiwan
| | - Mou-Tuan Huang
- Department of Chemical Biology; Rutgers-The State University of New Jersey; Piscataway NJ USA
| | - Chi-Tang Ho
- Department of Food Science; Rutgers-The State University of New Jersey; New Brunswick NJ USA
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Shao J, Zeng S, Zhou B, Xu H, Bian Y, Xu Y. Angiogenic factor with G patch and FHA domains 1 (Aggf1) promotes hepatic steatosis in mice. Biochem Biophys Res Commun 2016; 482:134-140. [PMID: 27865839 DOI: 10.1016/j.bbrc.2016.10.071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 11/18/2022]
Abstract
Increased uptake of nutrients coupled with reduced activity leads to the development of a host of metabolic disorders in humans. In the present study we examined the role of angiogenic factor with G patch and FHA domains 1 (Aggf1) in the pathogenesis of steatosis, characterized by accumulation of lipids in the liver and consequently hepatic insulin resistance. We report here that Aggf1 expression was up-regulated in the liver in both genetically predisposed and diet-induced mouse model of steatosis. Aggf1 expression was also stimulated by free fatty acids in primary hepatocytes. Over-expression of Aggf1 in mice promoted steatosis. On the contrary, Aggf1 depletion ameliorated steatosis in mice. Mechanistically, Aggf1 activated the expression of gluconeogenesis gene and skewed the insulin signaling pathway to induce insulin resistance. Taken together, our data suggest that Aggf1 plays a role in steatosis in vivo and as such may be a new target in the development of therapeutics solutions against steatosis.
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Affiliation(s)
- Jing Shao
- College of Basic Medical Sciences, Nanjing University of Chinese Medicine, Nanjing, China
| | - Sheng Zeng
- Department of Pathophysiology, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, China
| | - Bisheng Zhou
- Department of Pathophysiology, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, China.
| | - Huihui Xu
- Department of Pathophysiology, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, China
| | - Yaoyao Bian
- School of Nursing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yong Xu
- Department of Pathophysiology, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, China.
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Rines AK, Sharabi K, Tavares CDJ, Puigserver P. Targeting hepatic glucose metabolism in the treatment of type 2 diabetes. Nat Rev Drug Discov 2016; 15:786-804. [PMID: 27516169 DOI: 10.1038/nrd.2016.151] [Citation(s) in RCA: 215] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Type 2 diabetes mellitus is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycaemia. Although current diabetes treatments have exhibited some success in lowering blood glucose levels, their effect is not always sustained and their use may be associated with undesirable side effects, such as hypoglycaemia. Novel antidiabetic drugs, which may be used in combination with existing therapies, are therefore needed. The potential of specifically targeting the liver to normalize blood glucose levels has not been fully exploited. Here, we review the molecular mechanisms controlling hepatic gluconeogenesis and glycogen storage, and assess the prospect of therapeutically targeting associated pathways to treat type 2 diabetes.
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Affiliation(s)
- Amy K Rines
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Kfir Sharabi
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Clint D J Tavares
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Pere Puigserver
- Department of Cancer Biology, Dana-Farber Cancer Institute, and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Sadewa AH. Effect of 7-Hydroxy-2-(4-Hydroxy-3-Methoxy-Phenyl)-Chroman-4-One (Swietenia Macrophylla King Seed) on Retinol Binding Protein-4 and Phosphoenolpyruvate Carboxykinase Gene Expression in Type 2 Diabetic Rats. ROMANIAN JOURNAL OF DIABETES NUTRITION AND METABOLIC DISEASES 2016. [DOI: 10.1515/rjdnmd-2016-0030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Satapati S, Kucejova B, Duarte JAG, Fletcher JA, Reynolds L, Sunny NE, He T, Nair LA, Livingston KA, Fu X, Merritt ME, Sherry AD, Malloy CR, Shelton JM, Lambert J, Parks EJ, Corbin I, Magnuson MA, Browning JD, Burgess SC. Mitochondrial metabolism mediates oxidative stress and inflammation in fatty liver. J Clin Invest 2015; 125:4447-62. [PMID: 26571396 DOI: 10.1172/jci82204] [Citation(s) in RCA: 273] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/08/2015] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are critical for respiration in all tissues; however, in liver, these organelles also accommodate high-capacity anaplerotic/cataplerotic pathways that are essential to gluconeogenesis and other biosynthetic activities. During nonalcoholic fatty liver disease (NAFLD), mitochondria also produce ROS that damage hepatocytes, trigger inflammation, and contribute to insulin resistance. Here, we provide several lines of evidence indicating that induction of biosynthesis through hepatic anaplerotic/cataplerotic pathways is energetically backed by elevated oxidative metabolism and hence contributes to oxidative stress and inflammation during NAFLD. First, in murine livers, elevation of fatty acid delivery not only induced oxidative metabolism, but also amplified anaplerosis/cataplerosis and caused a proportional rise in oxidative stress and inflammation. Second, loss of anaplerosis/cataplerosis via genetic knockdown of phosphoenolpyruvate carboxykinase 1 (Pck1) prevented fatty acid-induced rise in oxidative flux, oxidative stress, and inflammation. Flux appeared to be regulated by redox state, energy charge, and metabolite concentration, which may also amplify antioxidant pathways. Third, preventing elevated oxidative metabolism with metformin also normalized hepatic anaplerosis/cataplerosis and reduced markers of inflammation. Finally, independent histological grades in human NAFLD biopsies were proportional to oxidative flux. Thus, hepatic oxidative stress and inflammation are associated with elevated oxidative metabolism during an obesogenic diet, and this link may be provoked by increased work through anabolic pathways.
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Sandoval DA, D'Alessio DA. Physiology of proglucagon peptides: role of glucagon and GLP-1 in health and disease. Physiol Rev 2015; 95:513-48. [PMID: 25834231 DOI: 10.1152/physrev.00013.2014] [Citation(s) in RCA: 286] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The preproglucagon gene (Gcg) is expressed by specific enteroendocrine cells (L-cells) of the intestinal mucosa, pancreatic islet α-cells, and a discrete set of neurons within the nucleus of the solitary tract. Gcg encodes multiple peptides including glucagon, glucagon-like peptide-1, glucagon-like peptide-2, oxyntomodulin, and glicentin. Of these, glucagon and GLP-1 have received the most attention because of important roles in glucose metabolism, involvement in diabetes and other disorders, and application to therapeutics. The generally accepted model is that GLP-1 improves glucose homeostasis indirectly via stimulation of nutrient-induced insulin release and by reducing glucagon secretion. Yet the body of literature surrounding GLP-1 physiology reveals an incompletely understood and complex system that includes peripheral and central GLP-1 actions to regulate energy and glucose homeostasis. On the other hand, glucagon is established principally as a counterregulatory hormone, increasing in response to physiological challenges that threaten adequate blood glucose levels and driving glucose production to restore euglycemia. However, there also exists a potential role for glucagon in regulating energy expenditure that has recently been suggested in pharmacological studies. It is also becoming apparent that there is cross-talk between the proglucagon derived-peptides, e.g., GLP-1 inhibits glucagon secretion, and some additive or synergistic pharmacological interaction between GLP-1 and glucagon, e.g., dual glucagon/GLP-1 agonists cause more weight loss than single agonists. In this review, we discuss the physiological functions of both glucagon and GLP-1 by comparing and contrasting how these peptides function, variably in concert and opposition, to regulate glucose and energy homeostasis.
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Affiliation(s)
- Darleen A Sandoval
- Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - David A D'Alessio
- Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio
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Kokil GR, Veedu RN, Ramm GA, Prins JB, Parekh HS. Type 2 diabetes mellitus: limitations of conventional therapies and intervention with nucleic acid-based therapeutics. Chem Rev 2015; 115:4719-43. [PMID: 25918949 DOI: 10.1021/cr5002832] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Ganesh R Kokil
- †School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Brisbane, QLD 4102, Australia
| | - Rakesh N Veedu
- §Center for Comparative Genomics, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.,∥Western Australian Neuroscience Research Institute, Perth, WA 6150, Australia.,‡School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane QLD 4072 Australia
| | - Grant A Ramm
- ⊥The Hepatic Fibrosis Group, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia.,#Faculty of Medicine and Biomedical Sciences, The University of Queensland, Brisbane, QLD 4006, Australia
| | - Johannes B Prins
- ∇Mater Research Institute, The University of Queensland, Brisbane, QLD 4101, Australia
| | - Harendra S Parekh
- †School of Pharmacy, Pharmacy Australia Centre of Excellence, The University of Queensland, Brisbane, QLD 4102, Australia
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Elevated hepatic 11β-hydroxysteroid dehydrogenase type 1 induces insulin resistance in uremia. Proc Natl Acad Sci U S A 2014; 111:3817-22. [PMID: 24569863 DOI: 10.1073/pnas.1312436111] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Insulin resistance and associated metabolic sequelae are common in chronic kidney disease (CKD) and are positively and independently associated with increased cardiovascular mortality. However, the pathogenesis has yet to be fully elucidated. 11β-Hydroxysteroid dehydrogenase type 1 (11βHSD1) catalyzes intracellular regeneration of active glucocorticoids, promoting insulin resistance in liver and other metabolic tissues. Using two experimental rat models of CKD (subtotal nephrectomy and adenine diet) which show early insulin resistance, we found that 11βHSD1 mRNA and protein increase in hepatic and adipose tissue, together with increased hepatic 11βHSD1 activity. This was associated with intrahepatic but not circulating glucocorticoid excess, and increased hepatic gluconeogenesis and lipogenesis. Oral administration of the 11βHSD inhibitor carbenoxolone to uremic rats for 2 wk improved glucose tolerance and insulin sensitivity, improved insulin signaling, and reduced hepatic expression of gluconeogenic and lipogenic genes. Furthermore, 11βHSD1(-/-) mice and rats treated with a specific 11βHSD1 inhibitor (UE2316) were protected from metabolic disturbances despite similar renal dysfunction following adenine experimental uremia. Therefore, we demonstrate that elevated hepatic 11βHSD1 is an important contributor to early insulin resistance and dyslipidemia in uremia. Specific 11βHSD1 inhibitors potentially represent a novel therapeutic approach for management of insulin resistance in patients with CKD.
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Guo P, You JO, Yang J, Jia D, Moses MA, Auguste DT. Inhibiting metastatic breast cancer cell migration via the synergy of targeted, pH-triggered siRNA delivery and chemokine axis blockade. Mol Pharm 2014; 11:755-65. [PMID: 24467226 PMCID: PMC3993942 DOI: 10.1021/mp4004699] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Because breast cancer patient survival inversely correlates with metastasis, we engineered vehicles to inhibit both the C-X-C chemokine receptor type 4 (CXCR4) and lipocalin-2 (Lcn2) mediated migratory pathways. pH-responsive liposomes were designed to protect and trigger the release of Lcn2 siRNA. Liposomes were modified with anti-CXCR4 antibodies to target metastatic breast cancer (MBC) cells and block migration along the CXCR4-CXCL12 axis. This synergistic approach--coupling the CXCR4 axis blockade with Lcn2 silencing--significantly reduced migration in triple-negative human breast cancer cells (88% for MDA-MB-436 and 92% for MDA-MB-231). The results suggested that drug delivery vehicles engineered to attack multiple migratory pathways may effectively slow progression of MBC.
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Affiliation(s)
- Peng Guo
- Department of Biomedical Engineering, The City College of New York , 160 Convent Avenue, New York, New York 10031, United States
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Niu CS, Chen LJ, Niu HS. Antihyperglycemic action of rhodiola-aqeous extract in type1-like diabetic rats. Altern Ther Health Med 2014; 14:20. [PMID: 24417880 PMCID: PMC3897963 DOI: 10.1186/1472-6882-14-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 01/09/2014] [Indexed: 12/21/2022]
Abstract
Background Rhodiola rosea (Rhodiola) is a plant in the Crassulaceae family that grows in cold regions of the world. It is mainly used in clinics as an adaptogen. Recently, it has been mentioned that Rhodiola increases plasma β-endorphin to lower blood pressure. Thus, the present study aims to investigate the antidiabetic action of Rhodiola in relation to opioids in streptozotocin-induced diabetic rats (STZ-diabetic rats). Methods In the present study, the plasma glucose was analyzed with glucose oxidase method, and the determination of plasma β-endorphin was carried out using a commercially available enzyme-linked immunosorbent assay. The adrenalectomy of STZ-diabetic rats was used to evaluate the role of β-endorphin. In addition, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting analysis were performed to investigate mRNA and protein expressions. Results Rhodiola-water extract dose-dependently lowered the plasma glucose in STZ-diabetic rats and this action was reversed by blockade of opioid μ-receptors using cyprodime. An increase of plasma β-endorphin by rhodiola-water extract was also observed in same manner. The plasma glucose lowering action of rhodiola-water extract was attenuated in bilateral adrenalectomized rats. In addition, continuous administration of rhodiola-water extract for 3 days in STZ-diabetic rats resulted in an increased expression of glucose transporter subtype 4 (GLUT 4) in skeletal muscle and a marked reduction of phosphoenolpyruvate carboxykinase (PEPCK) expression in liver. These effects were also reversed by blockade of opioid μ-receptors. Conclusions Taken together, rhodiola-water extract improves hyperglycemia via an increase of β-endorphin secretion from adrenal gland to activate opioid μ-receptors in STZ-diabetic rats.
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Pan D, Zhang D, Wu J, Chen C, Xu Z, Yang H, Zhou P. Antidiabetic, antihyperlipidemic and antioxidant activities of a novel proteoglycan from ganoderma lucidum fruiting bodies on db/db mice and the possible mechanism. PLoS One 2013; 8:e68332. [PMID: 23874589 PMCID: PMC3708940 DOI: 10.1371/journal.pone.0068332] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 05/28/2013] [Indexed: 11/25/2022] Open
Abstract
Previously, we screened a proteoglycan for anti-hyperglycemic, named FYGL, from Ganoderma Lucidum. For further research of the antidiabetic mechanisms of FYGL in vivo, the glucose homeostasis, activities of insulin-sensitive enzymes, glucose transporter expression and pancreatic function were analyzed using db/db mice as diabetic models in the present work. FYGL not only lead to a reduction in glycated hemoglobin level, but also an increase in insulin and C-peptide level, whereas a decrease in glucagons level and showed a potential for the remediation of pancreatic islets. FYGL also increased the glucokinase activities, and simultaneously lowered the phosphoenol pyruvate carboxykinase activities, accompanied by a reduction in the expression of hepatic glucose transporter protein 2, while the expression of adipose and skeletal glucose transporter protein 4 was increased. Moreover, the antioxidant enzyme activities were also increased by FYGL treatment. Thus, FYGL was an effective antidiabetic agent by enhancing insulin secretion and decreasing hepatic glucose output along with increase of adipose and skeletal muscle glucose disposal in the late stage of diabetes. Furthermore, FYGL is beneficial against oxidative stress, thereby being helpful in preventing the diabetic complications.
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Affiliation(s)
- Deng Pan
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
| | - Dang Zhang
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, P. R. China
| | - Jiasheng Wu
- Pharmacy College, Shanghai University of Traditional Chinese Medicine, Shanghai, P. R. China
| | - Congheng Chen
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
| | - Zhixue Xu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
| | - Hongjie Yang
- Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, P. R. China
- * E-mail: (PZ); (HY)
| | - Ping Zhou
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, P. R. China
- * E-mail: (PZ); (HY)
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Méndez-Lucas A, Duarte J, Sunny NE, Satapati S, He T, Fu X, Bermúdez J, Burgess SC, Perales JC. PEPCK-M expression in mouse liver potentiates, not replaces, PEPCK-C mediated gluconeogenesis. J Hepatol 2013; 59:105-13. [PMID: 23466304 PMCID: PMC3910155 DOI: 10.1016/j.jhep.2013.02.020] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/15/2013] [Accepted: 02/23/2013] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS Hepatic gluconeogenesis helps maintain systemic energy homeostasis by compensating for discontinuities in nutrient supply. Liver-specific deletion of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) abolishes gluconeogenesis from mitochondrial substrates, deregulates lipid metabolism and affects TCA cycle. While the mouse liver almost exclusively expresses PEPCK-C, humans equally present a mitochondrial isozyme (PEPCK-M). Despite clear relevance to human physiology, the role of PEPCK-M and its gluconeogenic potential remain unknown. Here, we test the significance of PEPCK-M in gluconeogenesis and TCA cycle function in liver-specific PEPCK-C knockout and WT mice. METHODS The effects of the overexpression of PEPCK-M were examined by a combination of tracer studies and molecular biology techniques. Partial PEPCK-C re-expression was used as a positive control. Metabolic fluxes were evaluated in isolated livers by NMR using (2)H and (13)C tracers. Gluconeogenic potential, together with metabolic profiling, was investigated in vivo and in primary hepatocytes. RESULTS PEPCK-M expression partially rescued defects in lipid metabolism, gluconeogenesis and TCA cycle function impaired by PEPCK-C deletion, while ∼10% re-expression of PEPCK-C normalized most parameters. When PEPCK-M was expressed in the presence of PEPCK-C, the mitochondrial isozyme amplified total gluconeogenic capacity, suggesting autonomous regulation of oxaloacetate to phosphoenolpyruvate fluxes by the individual isoforms. CONCLUSIONS We conclude that PEPCK-M has gluconeogenic potential per se, and cooperates with PEPCK-C to adjust gluconeogenic/TCA flux to changes in substrate or energy availability, hinting at a role in the regulation of glucose and lipid metabolism in the human liver.
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Affiliation(s)
- Andrés Méndez-Lucas
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - João Duarte
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
| | - Nishanth E. Sunny
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
| | - Santhosh Satapati
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
| | - TianTeng He
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
| | - Xiaorong Fu
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
| | - Jordi Bermúdez
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Shawn C. Burgess
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390-8568, USA
- Corresponding Authors. José C. Perales, Ph.D Associate Professor Departament de Ciències Fisiològiques II, Biophysics, University of Barcelona Feixa Llarga, s/n 08907 L'Hospitalet de Llobregat Barcelona, Spain +34 934024295 +34 934024268 (fax) , Shawn C. Burgess, Ph.D Associate Professor Department of Pharmacology and The Advanced Imaging Research Center 5323 Harry Hines Blvd. Dallas, Texas 75390-8568 +1 (214)645-2728 +1 (214)645-2744 (fax)
| | - Jose C. Perales
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
- Corresponding Authors. José C. Perales, Ph.D Associate Professor Departament de Ciències Fisiològiques II, Biophysics, University of Barcelona Feixa Llarga, s/n 08907 L'Hospitalet de Llobregat Barcelona, Spain +34 934024295 +34 934024268 (fax) , Shawn C. Burgess, Ph.D Associate Professor Department of Pharmacology and The Advanced Imaging Research Center 5323 Harry Hines Blvd. Dallas, Texas 75390-8568 +1 (214)645-2728 +1 (214)645-2744 (fax)
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Duan J, Shao F, Shao Y, Li J, Ling Y, Teng K, Li H, Wu C. Androgen inhibits abdominal fat accumulation and negatively regulates the PCK1 gene in male chickens. PLoS One 2013; 8:e59636. [PMID: 23544081 PMCID: PMC3609855 DOI: 10.1371/journal.pone.0059636] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 02/16/2013] [Indexed: 01/14/2023] Open
Abstract
Capons are male chickens whose testes have been surgically incised. Capons show a significant increase in fat accumulation compared to intact male chickens. However, while caponization leads to a significant reduction in androgen levels in roosters, little is known about the molecular mechanisms through which androgen status affects lipogenesis in avian species. Therefore, investigation of the influence of androgens on fat accumulation in the chicken will provide insights into this process. In this study, Affymetrix microarray technology was used to analyze the gene expression profiles of livers from capons and intact male chickens because the liver is the major site of lipogenesis in avian species. Through gene ontology, we found that genes involved in hepatic lipogenic biosynthesis were the most highly enriched. Interestingly, among the upregulated genes, the cytosolic form of the phosphoenolpyruvate carboxykinase (PCK1) gene showed the greatest fold change. Additionally, in conjunction with quantitative real-time PCR data, our results suggested that androgen status negatively regulated the PCK1 gene in male chickens.
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Affiliation(s)
- Jinlin Duan
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Fan Shao
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yonggang Shao
- College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, China
| | - Junying Li
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yao Ling
- College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Kedao Teng
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hongwei Li
- College of Animal Science and Technology, China Agricultural University, Beijing, China
- College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Changxin Wu
- College of Animal Science and Technology, China Agricultural University, Beijing, China
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Hsu FL, Huang CF, Chen YW, Yen YP, Wu CT, Uang BJ, Yang RS, Liu SH. Antidiabetic effects of pterosin A, a small-molecular-weight natural product, on diabetic mouse models. Diabetes 2013; 62:628-38. [PMID: 23069626 PMCID: PMC3554375 DOI: 10.2337/db12-0585] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The therapeutic effect of pterosin A, a small-molecular-weight natural product, on diabetes was investigated. Pterosin A, administered orally for 4 weeks, effectively improved hyperglycemia and glucose intolerance in streptozotocin, high-fat diet-fed, and db/db diabetic mice. There were no adverse effects in normal or diabetic mice treated with pterosin A for 4 weeks. Pterosin A significantly reversed the increased serum insulin and insulin resistance (IR) in dexamethasone-IR mice and in db/db mice. Pterosin A significantly reversed the reduced muscle GLUT-4 translocation and the increased liver phosphoenolpyruvate carboxyl kinase (PEPCK) expression in diabetic mice. Pterosin A also significantly reversed the decreased phosphorylations of AMP-activated protein kinase (AMPK) and Akt in muscles of diabetic mice. The decreased AMPK phosphorylation and increased p38 phosphorylation in livers of db/db mice were effectively reversed by pterosin A. Pterosin A enhanced glucose uptake and AMPK phosphorylation in cultured human muscle cells. In cultured liver cells, pterosin A inhibited inducer-enhanced PEPCK expression, triggered the phosphorylations of AMPK, acetyl CoA carboxylase, and glycogen synthase kinase-3, decreased glycogen synthase phosphorylation, and increased the intracellular glycogen level. These findings indicate that pterosin A may be a potential therapeutic option for diabetes.
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Affiliation(s)
- Feng-Lin Hsu
- Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan
| | - Chun-Fa Huang
- Graduate Institute of Chinese Medical Science, School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Ya-Wen Chen
- Department of Physiology, China Medical University, Taichung, Taiwan
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Yuan-Peng Yen
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Cheng-Tien Wu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Biing-Jiun Uang
- Department of Chemistry, College of Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Rong-Sen Yang
- Department of Orthopaedics, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Urology, College of Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Corresponding author: Shing-Hwa Liu,
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Decrease of Plasma Glucose by Hibiscus taiwanensisin Type-1-Like Diabetic Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:356705. [PMID: 23690841 PMCID: PMC3652199 DOI: 10.1155/2013/356705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/18/2013] [Accepted: 03/30/2013] [Indexed: 11/18/2022]
Abstract
Hibiscus taiwanensis (Malvaceae) is widely used as an alternative herb to treat disorders in Taiwan. In the present study, it is used to screen the effect on diabetic hyperglycemia in streptozotocin-induced diabetic rats (STZ-diabetic rats). The extract of Hibiscus taiwanensis showed a significant plasma glucose-lowering action in STZ-diabetic rats. Stems of Hibiscus taiwanensis are more effective than other parts to decrease the plasma glucose in a dose-dependent manner. Oral administration of Hibiscus taiwanensis three times daily for 3 days into STZ-diabetic rats increased the sensitivity to exogenous insulin showing an increase in insulin sensitivity. Moreover, similar repeated administration of Hibiscus taiwanensis for 3 days in STZ-diabetic rats produced a marked reduction of phosphoenolpyruvate carboxykinase (PEPCK) expression in liver and an increased expression of glucose transporter subtype 4 (GLUT 4) in skeletal muscle. Taken together, our results suggest that Hibiscus taiwanensis has the ability to lower plasma glucose through an increase in glucose utilization via elevation of skeletal GLUT 4 and decrease of hepatic PEPCK in STZ-diabetic rats.
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Citrus unshiu peel extract ameliorates hyperglycemia and hepatic steatosis by altering inflammation and hepatic glucose- and lipid-regulating enzymes in db/db mice. J Nutr Biochem 2012; 24:419-27. [PMID: 22694954 DOI: 10.1016/j.jnutbio.2011.12.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 12/15/2011] [Accepted: 12/22/2011] [Indexed: 12/15/2022]
Abstract
Insulin resistance in Type 2 diabetes leads to hepatic steatosis that can accompanied by progressive inflammation of the liver. Citrus unshiu peel is a rich source of citrus flavonoids that possess anti-inflammatory, anti-diabetic and lipid-lowering effects. However, the ability of citrus unshiu peel ethanol extract (CPE) to improve hyperglycemia, adiposity and hepatic steatosis in Type 2 diabetes is unknown. Thus, we evaluated the effects of CPE on markers for glucose, lipid metabolism and inflammation in Type 2 diabetic mice. Male C57BL/KsJ-db/db mice were fed a normal diet with CPE (2 g/100 g diet) or rosiglitazone (0.001 g/100 g diet) for 6 weeks. Mice supplemented with the CPE showed a significant decrease in body weight gain, body fat mass and blood glucose level. The antihyperglycemic effect of CPE appeared to be partially mediated through the inhibition of hepatic gluconeogenic phosphoenolpyruvate carboxykinase mRNA expression and its activity and through the induction of insulin/glucagon secretion. CPE also ameliorated hepatic steatosis and hypertriglyceridemia via the inhibition of gene expression and activities of the lipogenic enzymes and the activation of fatty acid oxidation in the liver. These beneficial effects of CPE may be related to increased levels of anti-inflammatory adiponectin and interleukin (IL)-10, and decreased levels of pro-inflammatory markers (IL-6, monocyte chemotactic protein-1, interferon-γ and tumor necrosis factor-α) in the plasma or liver. Taken together, we suggest that CPE has the potential to improve both hyperglycemia and hepatic steatosis in Type 2 diabetes.
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Vidal-Alabró A, Gómez-Valadés AG, Méndez-Lucas A, Llorens J, Bartrons R, Bermúdez J, Perales JC. Liver Glucokinase(A456V) Induces Potent Hypoglycemia without Dyslipidemia through a Paradoxical Induction of the Catalytic Subunit of Glucose-6-Phosphatase. Int J Endocrinol 2011; 2011:707928. [PMID: 22194744 PMCID: PMC3238378 DOI: 10.1155/2011/707928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 09/09/2011] [Indexed: 01/07/2023] Open
Abstract
Recent reports point out the importance of the complex GK-GKRP in controlling glucose and lipid homeostasis. Several GK mutations affect GKRP binding, resulting in permanent activation of the enzyme. We hypothesize that hepatic overexpression of a mutated form of GK, GK(A456V), described in a patient with persistent hyperinsulinemic hypoglycemia of infancy (PHHI) and could provide a model to study the consequences of GK-GKRP deregulation in vivo. GK(A456V) was overexpressed in the liver of streptozotocin diabetic mice. Metabolite profiling in serum and liver extracts, together with changes in key components of glucose and lipid homeostasis, were analyzed and compared to GK wild-type transfected livers. Cell compartmentalization of the mutant but not the wild-type GK was clearly affected in vivo, demonstrating impaired GKRP regulation. GK(A456V) overexpression markedly reduced blood glucose in the absence of dyslipidemia, in contrast to wild-type GK-overexpressing mice. Evidence in glucose utilization did not correlate with increased glycogen nor lactate levels in the liver. PEPCK mRNA was not affected, whereas the mRNA for the catalytic subunit of glucose-6-phosphatase was upregulated ~4 folds in the liver of GK(A456V)-treated animals, suggesting that glucose cycling was stimulated. Our results provide new insights into the complex GK regulatory network and validate liver-specific GK activation as a strategy for diabetes therapy.
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Affiliation(s)
- Anna Vidal-Alabró
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
| | - Alícia G. Gómez-Valadés
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
| | - Andrés Méndez-Lucas
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
| | - Jordi Llorens
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
| | - Ramon Bartrons
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
| | - Jordi Bermúdez
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
| | - Jose C. Perales
- Biophysics Unit, Department of Physiological Sciences II, IDIBELL-University of Barcelona, Campus de Bellvitge, 08907 L'Hospitalet de Llobregat, Spain
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Abstract
RNA interference (RNAi) is a robust gene silencing mechanism that degrades mRNAs complementary to the antisense strands of double-stranded, short interfering RNAs (siRNAs). As a therapeutic strategy, RNAi has an advantage over small-molecule drugs, as virtually all genes are susceptible to targeting by siRNA molecules. This advantage is, however, counterbalanced by the daunting challenge of achieving safe, effective delivery of oligonucleotides to specific tissues in vivo. Lipid-based carriers of siRNA therapeutics can now target the liver in metabolic diseases and are being assessed in clinical trials for the treatment of hypercholesterolemia. For this indication, a chemically modified oligonucleotide that targets endogenous small RNA modulators of gene expression (microRNAs) is also under investigation in clinical trials. Emerging 'self-delivery' siRNAs that are covalently linked to lipophilic moieties show promise for the future development of therapies. Besides the liver, inflammation of the adipose tissue in patients with obesity and type 2 diabetes mellitus may be an attractive target for siRNA therapeutics. Administration of siRNAs encapsulated within glucan microspheres can silence genes in inflammatory phagocytic cells, as can certain lipid-based carriers of siRNA. New technologies that combine siRNA molecules with antibodies or other targeting molecules also appear encouraging. Although still at an early stage, the emergence of RNAi-based therapeutics has the potential to markedly influence our clinical future.
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Affiliation(s)
- Michael P Czech
- University of Massachusetts Medical School, Worcester, MA 01605, USA.
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O'Geen H, Lin YH, Xu X, Echipare L, Komashko VM, He D, Frietze S, Tanabe O, Shi L, Sartor MA, Engel JD, Farnham PJ. Genome-wide binding of the orphan nuclear receptor TR4 suggests its general role in fundamental biological processes. BMC Genomics 2010; 11:689. [PMID: 21126370 PMCID: PMC3019231 DOI: 10.1186/1471-2164-11-689] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Accepted: 12/02/2010] [Indexed: 02/06/2023] Open
Abstract
Background The orphan nuclear receptor TR4 (human testicular receptor 4 or NR2C2) plays a pivotal role in a variety of biological and metabolic processes. With no known ligand and few known target genes, the mode of TR4 function was unclear. Results We report the first genome-wide identification and characterization of TR4 in vivo binding. Using chromatin immunoprecipitation followed by high throughput sequencing (ChIP-seq), we identified TR4 binding sites in 4 different human cell types and found that the majority of target genes were shared among different cells. TR4 target genes are involved in fundamental biological processes such as RNA metabolism and protein translation. In addition, we found that a subset of TR4 target genes exerts cell-type specific functions. Analysis of the TR4 binding sites revealed that less than 30% of the peaks from any of the cell types contained the DR1 motif previously derived from in vitro studies, suggesting that TR4 may be recruited to the genome via interaction with other proteins. A bioinformatics analysis of the TR4 binding sites predicted a cis regulatory module involving TR4 and ETS transcription factors. To test this prediction, we performed ChIP-seq for the ETS factor ELK4 and found that 30% of TR4 binding sites were also bound by ELK4. Motif analysis of the sites bound by both factors revealed a lack of the DR1 element, suggesting that TR4 binding at a subset of sites is facilitated through the ETS transcription factor ELK4. Further studies will be required to investigate the functional interdependence of these two factors. Conclusions Our data suggest that TR4 plays a pivotal role in fundamental biological processes across different cell types. In addition, the identification of cell type specific TR4 binding sites enables future studies of the pathways underlying TR4 action and its possible role in metabolic diseases.
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Affiliation(s)
- Henriette O'Geen
- Genome Center, University of California at Davis, Davis, CA 95616, USA
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Juan YC, Tsai WJ, Lin YL, Wang GJ, Cheng JJ, Yang HY, Hsu CY, Liu HK. The novel anti-hyperglycemic effect of Paeoniae radix via the transcriptional suppression of phosphoenopyruvate carboxykinase (PEPCK). PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2010; 17:626-634. [PMID: 20096551 DOI: 10.1016/j.phymed.2009.12.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 10/30/2009] [Accepted: 12/11/2009] [Indexed: 05/28/2023]
Abstract
The antidiabetic actions of Paeoniae Radix involve stimulating glucose uptake and reducing glucose absorption. However, the importance of this herb in the transcriptional regulation of hepatic gluconeogenesis has not previously been investigated, although hepatic gluconeogenesis contributes the most to fasting hyperglycemia. Using rats with streptozotocin-induced diabetes and db/db mice, the dose- and time-dependent suppressive effects of the ethanol extract of Paeoniae Radix (PR-Et) on diabetic hyperglycemia and phosphoenopyruvate carboxykinase (PEPCK) transcription are first demonstrated. Second, by employing H4IIE cells, the inhibitory action of PR-Et on both dexamethasone- and 8-bromo-cAMP-induced-PEPCK expression was also confirmed without causing any cytotoxicity. In addition, this inhibitory effect could be sustained for over 24 h with repeated treatment. Most importantly, PR-Et's action was unaffected by either insulin desensitization or palmitate stimulation. Finally, paeonol and paeoniflorin, two well-known constituents in Paeoniae Radix, did not suppress PEPCK expression at testing concentration. In conclusion, it was clearly demonstrated that transcriptional inhibition of gluconeogenesis is one of the important antidiabetic actions of Paeoniae Radix. Future development of this herb as a dietary supplement or drug should bring substantial benefits for the diabetic population.
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MESH Headings
- 8-Bromo Cyclic Adenosine Monophosphate
- Acetophenones/isolation & purification
- Acetophenones/pharmacology
- Acetophenones/therapeutic use
- Animals
- Benzoates/isolation & purification
- Benzoates/pharmacology
- Benzoates/therapeutic use
- Bridged-Ring Compounds/isolation & purification
- Bridged-Ring Compounds/pharmacology
- Bridged-Ring Compounds/therapeutic use
- Cell Line
- Dexamethasone
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Dose-Response Relationship, Drug
- Drugs, Chinese Herbal/chemistry
- Drugs, Chinese Herbal/pharmacology
- Drugs, Chinese Herbal/therapeutic use
- Gene Expression/drug effects
- Gluconeogenesis/drug effects
- Gluconeogenesis/genetics
- Glucosides/isolation & purification
- Glucosides/pharmacology
- Glucosides/therapeutic use
- Humans
- Hypoglycemic Agents/isolation & purification
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Insulin/metabolism
- Liver/drug effects
- Liver/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Monoterpenes
- Paeonia/chemistry
- Palmitic Acid/metabolism
- Phosphoenolpyruvate Carboxykinase (GTP)/genetics
- Phosphoenolpyruvate Carboxykinase (GTP)/metabolism
- Phytotherapy
- Plant Roots
- Rats
- Rats, Sprague-Dawley
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Affiliation(s)
- Y-C Juan
- Institute of Pharmacology, University of Yang Ming, Taipei, Taiwan, ROC
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Hsieh CW, Millward CA, DeSantis D, Pisano S, Machova J, Perales JC, Croniger CM. Reduced milk triglycerides in mice lacking phosphoenolpyruvate carboxykinase in mammary gland adipocytes and white adipose tissue contribute to the development of insulin resistance in pups. J Nutr 2009; 139:2257-65. [PMID: 19812223 PMCID: PMC2777474 DOI: 10.3945/jn.109.113092] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Obesity and type 2 diabetes are growing problems worldwide in adults and children. In this study, we focused on understanding the patterning of insulin resistance as a result of altered perinatal nutrition. We analyzed mice in which the binding site for PPARgamma was deleted from the promoter of the cytosolic phosphoenolpyruvate carboxykinase gene (Pck1) (PPARE(-/-)). We analyzed pups from dams with the same genotype as well as fostered and cross-fostered pups. Pck1 expression and triglyceride concentration in the milk were measured. The PPARE mutation reduced Pck1 expression in white adipose tissue (WAT) to 2.2% of wild type (WT) and reduced Pck1 expression in whole mammary gland tissue to 1% of WT. The female PPARE(-/-) mice had reduced lipid storage in mammary gland adipocytes and in WAT, resulting in a 40% reduction of milk triglycerides during lactation. Pups from PPARE(-/-) dams had insulin resistance as early as 14 d after birth, a condition that persisted into adulthood. WT pups fostered by PPARE(-/-) dams had lower body weights and plasma insulin concentrations compared with WT pups reared by WT dams. PPARE(-/-) pups fostered by WT dams had improved glucose clearance compared with pups raised by PPARE(-/-) dams. PPARE(+/-) and PPARE(-/-) dams also patterned newborn pups for reduced growth and insulin resistance in utero. Thus, the in utero environment and altered nutrition during the perinatal period cause epigenetic changes that persist into adulthood and contribute to the development of insulin resistance.
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Affiliation(s)
- Chang-Wen Hsieh
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain
| | - Carrie A. Millward
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain
| | - David DeSantis
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain
| | - Sorana Pisano
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain
| | - Jana Machova
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain
| | - Jose C. Perales
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain
| | - Colleen M. Croniger
- Department of Nutrition, Case Western Reserve University, Cleveland, OH 44106; and Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona 08907, Spain,To whom correspondence should be addressed. E-mail:
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Tsai NP, Huq M, Gupta P, Yamamoto K, Kagechika H, Wei LN. Activation of testicular orphan receptor 4 by fatty acids. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1789:734-40. [PMID: 19800043 DOI: 10.1016/j.bbagrm.2009.09.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 08/29/2009] [Accepted: 09/23/2009] [Indexed: 10/20/2022]
Abstract
Nuclear receptors can be activated by chemicals, metabolites, hormones or environmental compounds to regulate gene expression. Bioassay-guided screening of mouse tissue extracts found that natural fatty acids of a certain carbon length and level of unsaturation could activate the mouse orphan nuclear receptor, testicular orphan receptor 4 (TR4). Subsequent experiments focused on gamma-linoleic acid, a compound identified during screening of mouse tissues that exerts regulatory activity in TR4 transactivation assays. gamma-linoleic acid positively modulates TR4 activity to promote the expression of downstream genes such as apolipoprotein E (ApoE) and phosphoenolpyruvate carboxykinase, and to activate a reporter carrying direct repeat 1 from the ApoE promoter. It also induced the interaction of TR4 with transcription coregulators such as RIP140 and PCAF. Comparisons of transactivation by TR4 and the metabolism-related peroxisome proliferator-activated nuclear receptors indicate that gamma-linoleic acid regulation is specific to TR4. The data suggest that TR4 might exert its physiological function by sensing certain lipids. Identifying these compounds could be useful for examining the physiological pathways in which TR4 and its target genes are involved.
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Affiliation(s)
- Nien-Pei Tsai
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455-0217, USA
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Duran J, Obach M, Navarro-Sabate A, Manzano A, Gómez M, Rosa JL, Ventura F, Perales JC, Bartrons R. Pfkfb3 is transcriptionally upregulated in diabetic mouse liver through proliferative signals. FEBS J 2009; 276:4555-68. [PMID: 19645723 DOI: 10.1111/j.1742-4658.2009.07161.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The ubiquitous isoform of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (uPFK-2), a product of the Pfkfb3 gene, plays a crucial role in the control of glycolytic flux. In this study, we demonstrate that Pfkfb3 gene expression is increased in streptozotocin-induced diabetic mouse liver. The Pfkfb3/-3566 promoter construct linked to the luciferase reporter gene was delivered to the liver via hydrodynamic gene transfer. This promoter was upregulated in streptozotocin-induced diabetic mouse liver compared with transfected healthy cohorts. In addition, increases were observed in Pfkfb3 mRNA and uPFK-2 protein levels, and intrahepatic fructose-2,6-bisphosphate concentration. During streptozotocin-induced diabetes, phosphorylation of both p38 mitogen-activated protein kinase and Akt was detected, together with the overexpression of the proliferative markers cyclin D and E2F. These findings indicate that uPFK-2 induction is coupled to enhanced hepatocyte proliferation in streptozotocin-induced diabetic mouse liver. Expression decreased when hepatocytes were treated with either rapamycin or LY 294002. This shows that uPFK-2 regulation is phosphoinositide 3-kinase-Akt-mammalian target of rapamycin dependent. These results indicate that fructose-2,6-bisphosphate is essential to the maintenance of the glycolytic flux necessary for providing energy and biosynthetic precursors to dividing cells.
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Affiliation(s)
- Joan Duran
- Unitat Bioquímica i Biologia Molecular, Universitat de Barcelona, Spain
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Seto SW, Lam TY, Tam HL, Au ALS, Chan SW, Wu JH, Yu PHF, Leung GPH, Ngai SM, Yeung JHK, Leung PS, Lee SMY, Kwan YW. Novel hypoglycemic effects of Ganoderma lucidum water-extract in obese/diabetic (+db/+db) mice. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2009; 16:426-436. [PMID: 19109000 DOI: 10.1016/j.phymed.2008.10.004] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Revised: 09/08/2008] [Accepted: 10/23/2008] [Indexed: 05/27/2023]
Abstract
In this study, we evaluated the pharmacological effects of Ganoderma lucidum (G. lucidum) (water-extract) (0.003, 0.03 and 0.3g/kg, 4-week oral gavage) consumption using the lean (+db/+m) and the obese/diabetic (+db/+db) mice. Different physiological parameters (plasma glucose and insulin levels, lipoproteins-cholesterol levels, phosphoenolpyruvate carboxykinase (PEPCK), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA reductase) and isolated aorta relaxation of both species were measured and compared. G. lucidum (0.03 and 0.3g/kg) lowered the serum glucose level in +db/+db mice after the first week of treatment whereas a reduction was observed in +db/+m mice only fed with 0.3g/kg of G. lucidum at the fourth week. A higher hepatic PEPCK gene expression was found in +db/+db mice. G. lucidum (0.03 and 0.3g/kg) markedly reduced the PEPCK expression in +db/+db mice whereas the expression of PEPCK was attenuated in +db/+m mice (0.3g/kg G. lucidum). HMG CoA reductase protein expression (in both hepatic and extra-hepatic organs) and the serum insulin level were not altered by G. lucidum. These data demonstrate that G. lucidum consumption can provide beneficial effects in treating type 2 diabetes mellitus (T2DM) by lowering the serum glucose levels through the suppression of the hepatic PEPCK gene expression.
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Affiliation(s)
- S W Seto
- Institute of Vascular Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
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Dharmarajan L, Case CL, Dunten P, Mukhopadhyay B. Tyr235 of human cytosolic phosphoenolpyruvate carboxykinase influences catalysis through an anion-quadrupole interaction with phosphoenolpyruvate carboxylate. FEBS J 2009; 275:5810-9. [PMID: 19021757 DOI: 10.1111/j.1742-4658.2008.06702.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tyr235 of GTP-dependent phosphoenolpyruvate (PEP) carboxykinase is a fully invariant residue. The aromatic ring of this residue establishes an energetically favorable weak anion-quadrupole interaction with PEP carboxylate. The role of Tyr235 in catalysis was investigated via kinetic analysis of site-directed mutagenesis-derived variants. The Y235F change lowered the apparent K(m) for PEP by about six-fold, raised the apparent K(m) for Mn(2+) by about 70-fold, and decreased oxaloacetate (OAA)-forming activity by about 10-fold. These effects were due to an enhanced anion-quadrupole interaction between the aromatic side chain at position 235, which now lacked a hydroxyl group, and PEP carboxylate, which probably increased the distance between PEP and Mn(2+) and consequently affected the phosphoryl transfer step and overall catalysis. For the Y235A and Y235S changes, an elimination of the favorable edge-on interaction increased the apparent K(m) for PEP by four- and six-fold, respectively, and the apparent K(m) for Mn(2+) by eight- and six-fold, respectively. The pyruvate kinase-like activity, representing the PEP dephosphorylation step of the OAA-forming reaction, was affected by the substitutions in a similar way to the complete reaction. These observations indicate that the aromatic ring of Tyr235 helps to position PEP in the active site and the hydroxyl group allows an optimal PEP-Mn(2+) distance for efficient phosphoryl transfer and overall catalysis. The Y235A and Y235S changes drastically reduced the PEP-forming and OAA decarboxylase activities, probably due to the elimination of the stabilizing interaction between Tyr235 and the respective products, PEP and pyruvate.
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Affiliation(s)
- Lakshmi Dharmarajan
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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Abstract
As an important part of glucose metabolism in liver, hepatic gluconeogenesis is regulated by a series of transcription factors. FoxO1, CREB and PGC-1α cross talk with insulin- or glucagon-responsive transcription genes encoding the rate-limiting enzymes such as glucose-6-phosphatase (G-6-Pase) and phosphoenolpyruvate carboxykinase (PEPCK), which stimulate hepatic gluconeogenesis. In addition, many regulators such as orphan nuclear receptor Nur77 and TR4, cytokines resistin and adiponectin, free fatty acids, directly bound to transcription factors, repress or enhance their activity, hence affect the transcription. In insulin-resistance diseases, high blood glucose is often induced by the disturbed hepatic gluconeogenesis, and the transcription factors in gluconeogeneic signal pathways are potential therapeutic target. So controlling these transcription factors can decrease hepatic glucose production and effectively treat insulin-resistance syndrome.
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Gómez-Valadés AG, Méndez-Lucas A, Vidal-Alabró A, Blasco FX, Chillon M, Bartrons R, Bermúdez J, Perales JC. Pck1 gene silencing in the liver improves glycemia control, insulin sensitivity, and dyslipidemia in db/db mice. Diabetes 2008; 57:2199-210. [PMID: 18443203 PMCID: PMC2494684 DOI: 10.2337/db07-1087] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C; encoded by Pck1) catalyzes the first committed step in gluconeogenesis. Extensive evidence demonstrates a direct correlation between PEPCK-C activity and glycemia control. Therefore, we aimed to evaluate the metabolic impact and their underlying mechanisms of knocking down hepatic PEPCK-C in a type 2 diabetic model. RESEARCH DESIGN AND METHODS PEPCK-C gene targeting was achieved using adenovirus-transduced RNAi. The study assessed several clinical symptoms of diabetes and insulin signaling in peripheral tissues, in addition to changes in gene expression, protein, and metabolites in the liver. Liver bioenergetics was also evaluated. RESULTS Treatment resulted in reduced PEPCK-C mRNA and protein. After treatment, improved glycemia and insulinemia, lower triglyceride, and higher total and HDL cholesterol were measured. Unsterified fatty acid accumulation was observed in the liver, in the absence of de novo lipogenesis. Despite hepatic lipidosis, treatment resulted in improved insulin signaling in the liver, muscle, and adipose tissue. O(2) consumption measurements in isolated hepatocytes demonstrated unaltered mitochondrial function and a consequent increased cellular energy charge. Key regulatory factors (FOXO1, hepatocyte nuclear factor-4alpha, and peroxisome proliferator-activated receptor-gamma coactivator [PGC]-1alpha) and enzymes (G6Pase) implicated in gluconeogenesis were downregulated after treatment. Finally, the levels of Sirt1, a redox-state sensor that modulates gluconeogenesis through PGC-1alpha, were diminished. CONCLUSIONS Our observations indicate that silencing PEPCK-C has direct impact on glycemia control and energy metabolism and provides new insights into the potential significance of the enzyme as a therapeutic target for the treatment of diabetes.
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Affiliation(s)
- Alicia G Gómez-Valadés
- Biophysics Unit, Department de Ciències Fisiològuiques II, IDIBELL-University of Barcelona, Barcelona, Spain
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50
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Triggered release of siRNA from poly(ethylene glycol)-protected, pH-dependent liposomes. J Control Release 2008; 130:266-74. [PMID: 18601962 DOI: 10.1016/j.jconrel.2008.06.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 05/28/2008] [Accepted: 06/06/2008] [Indexed: 11/21/2022]
Abstract
The ability of small interfering RNA (siRNA) to regulate gene expression has potential therapeutic applications, but its use is limited by inefficient delivery. Triggered release of adsorbed poly(ethylene glycol) (PEG)-b-polycation polymers from pH-dependent (PD) liposomes enables protection from immune recognition during circulation (pH 7.4) and subsequent intracellular delivery of siRNA within the endosome (pH ~5.5). Polycationic blocks, based on either poly[2-(dimethylamino)ethyl methacrylate] (31 or 62 DMA repeat units) or polylysine (21 K repeat units), act as anchors for a PEG (113 ethylene glycol repeat units) protective block. Incorporation of 1,2-dioleoyl-3-dimethylammonium-propane (DAP), a titratable lipid, increases the liposome's net cationic character within acidic environments, resulting in polymer desorption and membrane fusion. Liposomes encapsulating siRNA demonstrate green fluorescent protein (GFP) silencing in genetically-modified, GFP-expressing HeLa cells and glyceraldehyde-3-phosphate dehydrogenase (GAPD) knockdown in human umbilical vein endothelial cells (HUVEC). Bare and PD liposomes coated with PEG113-DMA31 exhibit a 0.16+/-0.2 and 0.32+/-0.3 fraction of GFP knockdown, respectively. In contrast, direct siRNA administration and Oligofectamine complexed siRNA reduce GFP expression by 0.06+/-0.02 and 0.14+/-0.02 fractions, respectively. Our in vitro data indicates that polymer desorption from PD liposomes enhances siRNA-mediated gene knockdown.
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