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Den Hartogh DJ, Vlavcheski F, Tsiani E. Muscle Cell Insulin Resistance Is Attenuated by Rosmarinic Acid: Elucidating the Mechanisms Involved. Int J Mol Sci 2023; 24:ijms24065094. [PMID: 36982168 PMCID: PMC10049470 DOI: 10.3390/ijms24065094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/16/2023] [Accepted: 01/26/2023] [Indexed: 03/30/2023] Open
Abstract
Obesity and elevated blood free fatty acid (FFA) levels lead to impaired insulin action causing insulin resistance in skeletal muscle, and contributing to the development of type 2 diabetes mellitus (T2DM). Mechanistically, insulin resistance is associated with increased serine phosphorylation of the insulin receptor substrate (IRS) mediated by serine/threonine kinases including mTOR and p70S6K. Evidence demonstrated that activation of the energy sensor AMP-activated protein kinase (AMPK) may be an attractive target to counteract insulin resistance. We reported previously that rosemary extract (RE) and the RE polyphenol carnosic acid (CA) activated AMPK and counteracted the FFA-induced insulin resistance in muscle cells. The effect of rosmarinic acid (RA), another polyphenolic constituent of RE, on FFA-induced muscle insulin resistance has never been examined and is the focus of the current study. Muscle cell (L6) exposure to FFA palmitate resulted in increased serine phosphorylation of IRS-1 and reduced insulin-mediated (i) Akt activation, (ii) GLUT4 glucose transporter translocation, and (iii) glucose uptake. Notably, RA treatment abolished these effects, and restored the insulin-stimulated glucose uptake. Palmitate treatment increased the phosphorylation/activation of mTOR and p70S6K, kinases known to be involved in insulin resistance and RA significantly reduced these effects. RA increased the phosphorylation of AMPK, even in the presence of palmitate. Our data indicate that RA has the potential to counteract the palmitate-induced insulin resistance in muscle cells, and further studies are required to explore its antidiabetic properties.
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Affiliation(s)
- Danja J Den Hartogh
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Filip Vlavcheski
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Evangelia Tsiani
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada
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2
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Rachubik P, Rogacka D, Audzeyenka I, Szrejder M, Topolewska A, Rychłowski M, Piwkowska A. The Role of PKGIα and AMPK Signaling Interplay in the Regulation of Albumin Permeability in Cultured Rat Podocytes. Int J Mol Sci 2023; 24:ijms24043952. [PMID: 36835364 PMCID: PMC9964913 DOI: 10.3390/ijms24043952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023] Open
Abstract
The permeability of the glomerular filtration barrier (GFB) is mainly regulated by podocytes and their foot processes. Protein kinase G type Iα (PKGIα) and adenosine monophosphate-dependent kinase (AMPK) affect the contractile apparatus of podocytes and influence the permeability of the GFB. Therefore, we studied the interplay between PKGIα and AMPK in cultured rat podocytes. The glomerular permeability to albumin and transmembrane FITC-albumin flux decreased in the presence of AMPK activators and increased in the presence of PKG activators. The knockdown of PKGIα or AMPK with small-interfering RNA (siRNA) revealed a mutual interaction between PKGIα and AMPK and influenced podocyte permeability to albumin. Moreover, PKGIα siRNA activated the AMPK-dependent signaling pathway. AMPKα2 siRNA increased basal levels of phosphorylated myosin phosphate target subunit 1 and decreased the phosphorylation of myosin light chain 2. Podocytes that were treated with AMPK or PKG activators were characterized by the different organization of actin filaments within the cell. Our findings suggest that mutual interactions between PKGIα and AMPKα2 regulate the contractile apparatus and permeability of the podocyte monolayer to albumin. Understanding this newly identified molecular mechanism in podocytes provides further insights into the pathogenesis of glomerular disease and novel therapeutic targets for glomerulopathies.
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Affiliation(s)
- Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Correspondence: ; Tel.: +48-585235486
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Maria Szrejder
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Anna Topolewska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
| | - Michał Rychłowski
- Intercollegiate Faculty of Biotechnology, University of Gdansk, Medical University of Gdansk, Abrahama 58 St., 80-307 Gdansk, Poland
| | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Wita Stwosza 63 St., 80-308 Gdansk, Poland
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63 St., 80-308 Gdansk, Poland
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3
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Tawfik SM, Abdollah MRA, Elmazar MM, El-Fawal HAN, Abdelnaser A. Effects of Metformin Combined With Antifolates on HepG2 Cell Metabolism and Cellular Proliferation. Front Oncol 2022; 12:828988. [PMID: 35186762 PMCID: PMC8851913 DOI: 10.3389/fonc.2022.828988] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/11/2022] [Indexed: 11/16/2022] Open
Abstract
Hepatocellular carcinoma (HCC), one of the most prevalent types of cancers worldwide, continues to maintain high levels of resistance to standard therapy. As clinical data revealed poor response rates, the need for developing new methods has increased to improve the overall wellbeing of patients with HCC. Furthermore, a growing body of evidence shows that cancer metabolic changes are a key feature of many types of human malignancies. Metabolic reprogramming refers to cancer cells’ ability to change their metabolism in order to meet the increased energy demand caused by continuous growth, rapid proliferation, and other neoplastic cell characteristics. For these reasons, metabolic pathways may become new therapeutic and chemopreventive targets. The aim of this study was to investigate the metabolic alterations associated with metformin (MET), an anti-diabetic agent when combined with two antifolate drugs: trimethoprim (TMP) or methotrexate (MTX), and how metabolic changes within the cancer cell may be used to increase cellular death. In this study, single drugs and combinations were investigated using in vitro assays including cytotoxicity assay (MTT), RT-qPCR, annexin V/PI apoptosis assay, scratch wound assay and Seahorse XF analysis, on a human HCC cell line, HepG2. The cytotoxicity assay showed that the IC50 of MET as single therapy was 44.08 mM that was reduced to 22.73 mM and 29.29 mM when combined with TMP and MTX, respectively. The co-treatment of both drugs increased p53 and Bax apoptotic markers, while decreased the anti-apoptotic marker; Bcl-2. Both combinations increased the percentage of apoptotic cells and halted cancer cell migration when compared to MET alone. Furthermore, both combinations decreased the MET-induced increase in glycolysis, while also inducing mitochondrial damage, altering cancer cell bioenergetics. These findings provide an exciting insight into the anti-proliferative and apoptotic effects of MET and anti-folates on HepG2 cells, and how in combination, may potentially combat the aggressiveness of HCC.
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Affiliation(s)
- Sherouk M Tawfik
- Department of Chemistry, School of Sciences and Engineering, The American University in Cairo, Cairo, Egypt.,Department of Pharmacology and Biochemistry, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt.,The Center for Drug Research and Development (CDRD), Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Maha R A Abdollah
- Department of Pharmacology and Biochemistry, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt.,The Center for Drug Research and Development (CDRD), Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Mohey M Elmazar
- Department of Pharmacology and Biochemistry, Faculty of Pharmacy, The British University in Egypt (BUE), Cairo, Egypt
| | - Hassan A N El-Fawal
- Institute of Global Public Health, School of Sciences and Engineering, The American University in Cairo, Cairo, Egypt
| | - Anwar Abdelnaser
- Institute of Global Public Health, School of Sciences and Engineering, The American University in Cairo, Cairo, Egypt
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4
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Noser AA, Abdelmonsef AH, El-Naggar M, Salem MM. New Amino Acid Schiff Bases as Anticancer Agents via Potential Mitochondrial Complex I-Associated Hexokinase Inhibition and Targeting AMP-Protein Kinases/mTOR Signaling Pathway. Molecules 2021; 26:molecules26175332. [PMID: 34500765 PMCID: PMC8434356 DOI: 10.3390/molecules26175332] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/27/2021] [Accepted: 08/31/2021] [Indexed: 12/12/2022] Open
Abstract
Two series of novel amino acid Schiff base ligands containing heterocyclic moieties, such as quinazolinone 3–11 and indole 12–20 were successfully synthesized and confirmed by spectroscopic techniques and elemental analysis. Furthermore, all compounds were investigated in silico for their ability to inhibit mitochondrial NADH: ubiquinone oxidoreductase (complex I) by targeting the AMPK/mTOR signaling pathway and inhibiting hexokinase, a key glycolytic enzyme to prevent the Warburg effect in cancer cells. This inhibitory pathway may be an effective strategy to cause cancer cell death due to an insufficient amount of ATP. Our results revealed that, out of 18 compounds, two (11 and 20) were top-ranked as they exhibited the highest binding energies of −8.8, −13.0, −7.9, and −10.0 kcal/mol in the docking analysis, so they were then selected for in vitro assessment. Compound 11 promoted the best cytotoxic effect on MCF-7 with IC50 = 64.05 ± 0.14 μg/mL (0.135 mM) while compound 20 exhibited the best cytotoxic effect on MDA-231 with IC50 = 46.29 ± 0.09 μg/mL (0.166 mM) Compounds 11 and 20 showed significant activation of AMPK protein and oxidative stress, which led to elevated expression of p53 and Bax, reduced Bcl-2 expression, and caused cell cycle arrest at the sub-G0/G1 phase. Moreover, compounds 11 and 20 showed significant inhibition of the mTOR protein, which led to the activation of aerobic glycolysis for survival. This alternative pathway was also blocked as compounds 11 and 20 showed significant inhibitory effects on the hexokinase enzyme. These findings demonstrate that compounds 11 and 20 obeyed Lipinski’s rule of five and could be used as privileged scaffolds for cancer therapy via their potential inhibition of mitochondrial complex I-associated hexokinase.
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Affiliation(s)
- Ahmed A. Noser
- Organic Chemistry Division, Chemistry Department, Faculty of Science, Tanta University, Tanta 31527, Egypt;
| | - Aboubakr H. Abdelmonsef
- Chemistry Department, Faculty of Science, South Valley University, Qena 83523, Egypt
- Correspondence: ; Tel.: +20-10-989-65494
| | - Mohamed El-Naggar
- Chemistry Department, Faculty of Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates;
| | - Maha M. Salem
- Biochemistry Division, Chemistry Department, Faculty of Science, Tanta University, Tanta 31527, Egypt;
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5
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Alghamdi F, Alshuweishi Y, Salt IP. Regulation of nutrient uptake by AMP-activated protein kinase. Cell Signal 2020; 76:109807. [DOI: 10.1016/j.cellsig.2020.109807] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 02/07/2023]
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6
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Soliman A, De Sanctis V, Alaaraj N, Hamed N. The clinical application of metformin in children and adolescents: A short update. ACTA BIO-MEDICA : ATENEI PARMENSIS 2020; 91:e2020086. [PMID: 32921782 PMCID: PMC7717009 DOI: 10.23750/abm.v91i3.10127] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/25/2022]
Abstract
Metformin is a widely used drug that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The global increase in the prevalence of obesity among children and adolescents is accompanied by the appearance and increasing prevalence of insulin resistance, prediabetes, and type 2 diabetes mellitus (T2DM). In addition, children, and adolescents with premature pubarche and polycystic ovary have considerable degree of insulin resistance. The insulin sensitizing actions of metformin encouraged many investigators and physician to use it as the key drug in these conditions for both prevention and treatment. However, long term-controlled studies are still required to assess the degree and duration of effectiveness and safety of using metformin. This review tries to update physicians about the main and the new therapeutic perspectives of this drug.
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Affiliation(s)
- Ashraf Soliman
- Department of Pediatrics, Division of Endocrinology, Hamad General Hospital, Doha, Qatar.
| | - Vincenzo De Sanctis
- Pediatric and Adolescent Outpatient Clinic, Quisisana Hospital, Ferrara, Italy.
| | - Nada Alaaraj
- Department of Pediatrics, Division of Endocrinology, Hamad General Hospital, Doha, Qatar.
| | - Noor Hamed
- Department of Pediatrics, Division of Endocrinology, Hamad General Hospital, Doha, Qatar.
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7
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Metformin reduces TRPC6 expression through AMPK activation and modulates cytoskeleton dynamics in podocytes under diabetic conditions. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165610. [DOI: 10.1016/j.bbadis.2019.165610] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 11/20/2022]
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8
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Attenuation of Free Fatty Acid-Induced Muscle Insulin Resistance by Rosemary Extract. Nutrients 2018; 10:nu10111623. [PMID: 30400151 PMCID: PMC6267446 DOI: 10.3390/nu10111623] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/24/2018] [Accepted: 10/29/2018] [Indexed: 12/13/2022] Open
Abstract
Elevated blood free fatty acids (FFAs), as seen in obesity, impair muscle insulin action leading to insulin resistance and Type 2 diabetes mellitus. Serine phosphorylation of the insulin receptor substrate (IRS) is linked to insulin resistance and a number of serine/threonine kinases including JNK, mTOR and p70 S6K have been implicated in this process. Activation of the energy sensor AMP-activated protein kinase (AMPK) increases muscle glucose uptake, and in recent years AMPK has been viewed as an important target to counteract insulin resistance. We reported recently that rosemary extract (RE) increased muscle cell glucose uptake and activated AMPK. However, the effect of RE on FFA-induced muscle insulin resistance has never been examined. In the current study, we investigated the effect of RE in palmitate-induced insulin resistant L6 myotubes. Exposure of myotubes to palmitate reduced the insulin-stimulated glucose uptake, increased serine phosphorylation of IRS-1, and decreased the insulin-stimulated phosphorylation of Akt. Importantly, exposure to RE abolished these effects and the insulin-stimulated glucose uptake was restored. Treatment with palmitate increased the phosphorylation/activation of JNK, mTOR and p70 S6K whereas RE completely abolished these effects. RE increased the phosphorylation of AMPK even in the presence of palmitate. Our data indicate that rosemary extract has the potential to counteract the palmitate-induced muscle cell insulin resistance and further studies are required to explore its antidiabetic properties.
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9
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Dolinar K, Jan V, Pavlin M, Chibalin AV, Pirkmajer S. Nucleosides block AICAR-stimulated activation of AMPK in skeletal muscle and cancer cells. Am J Physiol Cell Physiol 2018; 315:C803-C817. [PMID: 30230919 DOI: 10.1152/ajpcell.00311.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
AMP-activated kinase (AMPK) is a major regulator of energy metabolism and a promising target for development of new treatments for type 2 diabetes and cancer. 5-Aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), an adenosine analog, is a standard positive control for AMPK activation in cell-based assays. Some broadly used cell culture media, such as minimal essential medium α (MEMα), contain high concentrations of adenosine and other nucleosides. We determined whether such media alter AICAR action in skeletal muscle and cancer cells. In nucleoside-free media, AICAR stimulated AMPK activation, increased glucose uptake, and suppressed cell proliferation. Conversely, these effects were blunted or completely blocked in MEMα that contains nucleosides. Addition of adenosine or 2'-deoxyadenosine to nucleoside-free media also suppressed AICAR action. MEMα with nucleosides blocked AICAR-stimulated AMPK activation even in the presence of methotrexate, which normally markedly enhances AICAR action by reducing its intracellular clearance. Other common media components, such as vitamin B-12, vitamin C, and α-lipoic acid, had a minor modulatory effect on AICAR action. Our findings show that nucleoside-containing media, commonly used in AMPK research, block action of the most widely used pharmacological AMPK activator AICAR. Results of cell-based assays in which AICAR is used for AMPK activation therefore critically depend on media formulation. Furthermore, our findings highlight a role for extracellular nucleosides and nucleoside transporters in regulation of AMPK activation.
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Affiliation(s)
- Klemen Dolinar
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana , Ljubljana , Slovenia.,Group for Nano and Biotechnological Applications, Faculty of Electrical Engineering, University of Ljubljana , Ljubljana , Slovenia
| | - Vid Jan
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana , Ljubljana , Slovenia
| | - Mojca Pavlin
- Group for Nano and Biotechnological Applications, Faculty of Electrical Engineering, University of Ljubljana , Ljubljana , Slovenia.,Institute of Biophysics, Faculty of Medicine, University of Ljubljana , Ljubljana , Slovenia
| | - Alexander V Chibalin
- Department of Molecular Medicine and Surgery, Integrative Physiology, Karolinska Institutet , Stockholm , Sweden.,National Research Tomsk State University , Tomsk , Russia
| | - Sergej Pirkmajer
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana , Ljubljana , Slovenia
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10
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Migdadi EM, Courtenay AJ, Tekko IA, McCrudden MTC, Kearney MC, McAlister E, McCarthy HO, Donnelly RF. Hydrogel-forming microneedles enhance transdermal delivery of metformin hydrochloride. J Control Release 2018; 285:142-151. [PMID: 29990526 PMCID: PMC6141810 DOI: 10.1016/j.jconrel.2018.07.009] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 07/03/2018] [Accepted: 07/04/2018] [Indexed: 11/22/2022]
Abstract
We investigated, for the first time, the potential for a hydrogel-forming microneedle (MN) patch to deliver the high-dose drug metformin HCl transdermally in a sustained manner. This may minimize some gastrointestinal side effects and small intestine absorption variations associated with oral delivery. Patches (two layers) were assembled from a lyophilised drug reservoir layer, with the MN layer made from aqueous blend of 20% w/w poly (methylvinylether-co-maleic acid) crosslinked by esterification with 7.5% w/w poly (ethylene glycol) 10,000 Da. >90% of metformin was recovered from homogeneous drug reservoirs. Drug reservoir dissolution time in PBS (pH 7.4) was <10 min. MN penetrated a validated skin model Parafilm® M consistently. Permeation of metformin HCl across dermatomed neonatal porcine skin in vitro was enhanced by using MN. The combined MN and metformin HCl reservoir patch (containing 75 mg or 50 mg metformin HCl, respectively) delivered 9.71 ± 2.22 mg and 10.04 ± 1.92 mg at 6 h, respectively, and 28.15 ± 2.37 mg and 23.25 ± 3.58 mg at 24 h, respectively.In comparison, 0.34 ± 0.39 mg and 0.85 ± 0.68 mg was delivered at 6 h, respectively, and 0.39 ± 0.39 mg and 1.01 ± 0.84 mg was delivered at 24 h, respectively, from a control set-up employing only the drug reservoirs. In vivo, metformin HCl was detected in rat plasma at 1 h post MN application at a concentration of 0.62 ± 0.51 μg/mL, increasing to 3.76 ± 2.58 μg/ml at 3 h. A maximal concentration of 3.77 ± 2.09 μg/ml was achieved at 24 h. Css was 3.2 μg/mL. Metformin transdermal bioavailability using MNs was estimated as 30%.Hydrogel-forming MN are a promising technology that has demonstrated successful transdermal delivery of metformin HCl. Potential clearly exists for administration of other high-dose drugs using this system.
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Affiliation(s)
- Eman M Migdadi
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; School of Pharmacy, Applied Science Private University, Amman, Jordan
| | - Aaron J Courtenay
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Ismaiel A Tekko
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; School of Pharmacy, University of Aleppo, Aleppo, Syria
| | | | - Mary-Carmel Kearney
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Emma McAlister
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Helen O McCarthy
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Ryan F Donnelly
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
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11
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Short-term treatment with metformin reduces hepatic lipid accumulation but induces liver inflammation in obese mice. Inflammopharmacology 2018; 26:1103-1115. [PMID: 29450671 DOI: 10.1007/s10787-018-0443-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 01/12/2018] [Indexed: 12/11/2022]
Abstract
The study aimed to evaluate the metabolic and inflammatory effects of short-term treatments (10 days) with metformin (MET) on the NAFLD caused by a high-fat diet (HFD) in C57BL/6 mice. After the treatment, histological liver slices were obtained, hepatocytes and macrophages were extracted and cultured with phosphate buffered saline, LPS (2.5 µg/mL) and MET (1 µM) for 24 h. Cytokine levels were determined by ELISA. NAFLD caused by the HFD was partially reduced by MET. The lipid accumulation induced by the HFD was not associated with liver inflammation; however, MET seemed to promote pro-inflammatory effects in liver, since it increased hepatic concentration of IL-1β, TNF-α, IL-6, MCP-1 and IFN-γ. Similarly, MET increased the concentration of IL-1β, IL-6 in hepatocyte cultures. However, in macrophages culture, MET lowered levels of IL-1β, IL-6 and TNF-α stimulated by LPS. Overall, MET reduced liver NAFLD but promoted hepatocyte increase in pro-inflammatory cytokines, thus, leading to liver inflammation.
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12
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Rogacka D, Audzeyenka I, Rychłowski M, Rachubik P, Szrejder M, Angielski S, Piwkowska A. Metformin overcomes high glucose-induced insulin resistance of podocytes by pleiotropic effects on SIRT1 and AMPK. Biochim Biophys Acta Mol Basis Dis 2018; 1864:115-125. [DOI: 10.1016/j.bbadis.2017.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/08/2017] [Accepted: 10/11/2017] [Indexed: 01/09/2023]
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13
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Andrzejewski S, Siegel PM, St-Pierre J. Metabolic Profiles Associated With Metformin Efficacy in Cancer. Front Endocrinol (Lausanne) 2018; 9:372. [PMID: 30186229 PMCID: PMC6110930 DOI: 10.3389/fendo.2018.00372] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/21/2018] [Indexed: 12/18/2022] Open
Abstract
Metformin is one of the most commonly prescribed medications for the treatment of type 2 diabetes. Numerous reports have suggested potential anti-cancerous and cancer preventive properties of metformin, although these findings vary depending on the intrinsic properties of the tumor, as well as the systemic physiology of patients. These intriguing studies have led to a renewed interest in metformin use in the oncology setting, and fueled research to unveil its elusive mode of action. It is now appreciated that metformin inhibits complex I of the electron transport chain in mitochondria, causing bioenergetic stress in cancer cells, and rendering them dependent on glycolysis for ATP production. Understanding the mode of action of metformin and the consequences of its use on cancer cell bioenergetics permits the identification of cancer types most susceptible to metformin action. Such knowledge may also shed light on the varying results to metformin usage that have been observed in clinical trials. In this review, we discuss metabolic profiles of cancer cells that are associated with metformin sensitivity, and rationalize combinatorial treatment options. We use the concept of bioenergetic flexibility, which has recently emerged in the field of cancer cell metabolism, to further understand metabolic rearrangements that occur upon metformin treatment. Finally, we advance the notion that metabolic fitness of cancer cells increases during progression to metastatic disease and the emergence of therapeutic resistance. As a result, sophisticated combinatorial approaches that prevent metabolic compensatory mechanisms will be required to effectively manage metastatic disease.
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Affiliation(s)
- Sylvia Andrzejewski
- Department of Biochemistry, McGill University, Montreal, QC, Canada
- Goodman Cancer Research Centre, McGill University, Montreal, QC, Canada
| | - Peter M. Siegel
- Department of Biochemistry, McGill University, Montreal, QC, Canada
- Goodman Cancer Research Centre, McGill University, Montreal, QC, Canada
| | - Julie St-Pierre
- Department of Biochemistry, Microbiology and Immunology, and Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
- *Correspondence: Julie St-Pierre
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Lopez-Carmona MD, Plaza-Seron MC, Vargas-Candela A, Tinahones FJ, Gomez-Huelgas R, Bernal-Lopez MR. CD36 overexpression: a possible etiopathogenic mechanism of atherosclerosis in patients with prediabetes and diabetes. Diabetol Metab Syndr 2017; 9:55. [PMID: 28729885 PMCID: PMC5516302 DOI: 10.1186/s13098-017-0253-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 07/12/2017] [Indexed: 01/28/2023] Open
Abstract
RATIONALE CD36 is a scavenger receptor located on monocytes which is involved in foam cell transformation. AIM To evaluate CD36 expression under different glycemic states in both healthy subjects and in atherosclerotic patients. SUBJECTS AND METHODS In order to evaluate the possible effects of hyperglycemia on CD36 expression in healthy subjects, an in vitro experiment was carried out using monocyte in three different conditions: extreme hyperglycemia (HG), euglycemia (EG) and in the absence of glucose. On the other hand, three groups of atherosclerotic patients were evaluated according to their glycemic conditions: normoglycemic (NG), prediabetic (preDM) and diabetic (DM) patients. CD36 expression (mRNA, non-glycated and glycated protein) was analyzed in monocytes. RESULTS CD36 mRNA expression in the in vitro experiment peaked at 4 and 24 h under HG conditions. No differences in mRNA levels were found in the EG and control group. The level of non-glycated proteins was higher in HG and EG conditions compared with control group. Glycated protein expression was inhibited by glucose in a sustained manner. In atherosclerotic patients, a significant association was observed when comparing glycated CD36 protein expression in DM with NG patients (p = 0.03). No significant differences were found in mRNA and non-glycated CD36 expression in these patients. Moreover, BMI, insulin, weight and treatment were shown to be related to CD36 expression (mRNA, non-glycated and glycated protein levels, depending of the case) in atherosclerotic patients. CONCLUSIONS Hyperglycemia is an important modulator of CD36 mRNA and non-glycated protein expression in vitro, increasing de novo synthesis in healthy subjects. In atherosclerotic patients, there are progressive increases in CD36 receptors, which may be due to a post-translational stimulus.
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Affiliation(s)
- M. D. Lopez-Carmona
- Internal Medicine Department, Biomedical Institute of Malaga (IBIMA), Regional University Hospital of Malaga (Carlos Haya Hospital), Avda. Hospital Civil s/n, 29009 Malaga, Spain
| | - M. C. Plaza-Seron
- Research Laboratory-Allergy Unit, Biomedical Institute of Malaga (IBIMA), Regional University Hospital of Malaga (Carlos Haya Hospital), Malaga, Spain
| | - A. Vargas-Candela
- Internal Medicine Department, Biomedical Institute of Malaga (IBIMA), Regional University Hospital of Malaga (Carlos Haya Hospital), Avda. Hospital Civil s/n, 29009 Malaga, Spain
| | - F. J. Tinahones
- Endocrinology and Nutrition Department, Biomedical Institute of Malaga (IBIMA), Regional University Hospital of Malaga (Virgen de la Victoria Hospital), Malaga, Spain
- CIBERFisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - R. Gomez-Huelgas
- Internal Medicine Department, Biomedical Institute of Malaga (IBIMA), Regional University Hospital of Malaga (Carlos Haya Hospital), Avda. Hospital Civil s/n, 29009 Malaga, Spain
- CIBERFisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - M. R. Bernal-Lopez
- Internal Medicine Department, Biomedical Institute of Malaga (IBIMA), Regional University Hospital of Malaga (Carlos Haya Hospital), Avda. Hospital Civil s/n, 29009 Malaga, Spain
- CIBERFisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
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Moon JS, Karunakaran U, Elumalai S, Lee IK, Lee HW, Kim YW, Won KC. Metformin prevents glucotoxicity by alleviating oxidative and ER stress-induced CD36 expression in pancreatic beta cells. J Diabetes Complications 2017; 31:21-30. [PMID: 27662780 DOI: 10.1016/j.jdiacomp.2016.09.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/18/2016] [Accepted: 09/05/2016] [Indexed: 12/27/2022]
Abstract
AIM/HYPOTHESIS Cluster determinant 36 (CD36), a fatty acid transporter, was reported to have a pivotal role in glucotoxicity-induced beta cell dysfunction. However, little is known about how glucotoxicity influences CD36 expression, and it is unknown whether this action can be counteracted by metformin. In the present study, we showed that metformin counteracts glucotoxicity by alleviating oxidative and endoplasmic reticulum (ER) stress-induced CD36 expression. METHODS We used primary rat islets as well as INS-1 cells for 72h to 24h with 30mM glucose, respectively. Thapsigargin was used as strong ER stressor, and Sulfo-N-succinimidyl oleate (SSO) and RNA interference were chosen for CD36 inhibition. Free fatty acid uptake was measured by radioisotope tracing technique. RESULTS Exposure of isolated rat islets to high glucose (HG) for 3days decreased insulin and pancreatic duodenal homeobox1 (Pdx1) mRNA expression, with the suppression of glucose-stimulated insulin secretion (GSIS) along with elevation of reactive oxygen species (ROS) levels. Incubation with metformin restored insulin and Pdx1 mRNA expression with significant improvements in GSIS and decrease in ROS production. HG exposure in INS-1 cells increased free fatty acid uptake via induction of CD36 along with impaired insulin and Pdx1 mRNA expression. Moreover, thapsigargin also increased the induction of CD36 expression. Metformin blocked HG- and thapsigargin-induced CD36 expression. In addition, the simultaneous inhibition of intracellular ROS production by metformin or CD36 activation by SSO or CD36 siRNA significantly decreased the apoptotic response in HG-treated INS-1 cells. CONCLUSION/INTERPRETATION In conclusion, metformin conferred protection against HG-induced apoptosis of pancreatic beta cells, largely by interfering with ROS production, and inhibited the CD36-mediated free fatty acid influx. This report provides evidence that the inhibition of CD36 may have potential therapeutic effects against hyperglycemia-induced beta cell damage in diabetes.
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Affiliation(s)
- Jun Sung Moon
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Udayakumar Karunakaran
- Institute of Medical Science, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Suma Elumalai
- Institute of Medical Science, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - In-Kyu Lee
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu
| | - Hyoung Woo Lee
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Yong-Woon Kim
- Department of Physiology, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Kyu Chang Won
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea; Institute of Medical Science, Yeungnam University College of Medicine, Daegu, Republic of Korea.
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Krolopp JE, Thornton SM, Abbott MJ. IL-15 Activates the Jak3/STAT3 Signaling Pathway to Mediate Glucose Uptake in Skeletal Muscle Cells. Front Physiol 2016; 7:626. [PMID: 28066259 PMCID: PMC5167732 DOI: 10.3389/fphys.2016.00626] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/30/2016] [Indexed: 12/19/2022] Open
Abstract
Myokines are specialized cytokines that are secreted from skeletal muscle (SKM) in response to metabolic stimuli, such as exercise. Interleukin-15 (IL-15) is a myokine with potential to reduce obesity and increase lean mass through induction of metabolic processes. It has been previously shown that IL-15 acts to increase glucose uptake in SKM cells. However, the downstream signals orchestrating the link between IL-15 signaling and glucose uptake have not been fully explored. Here we employed the mouse SKM C2C12 cell line to examine potential downstream targets of IL-15-induced alterations in glucose uptake. Following differentiation, C2C12 cells were treated overnight with 100 ng/ml of IL-15. Activation of factors associated with glucose metabolism (Akt and AMPK) and known downstream targets of IL-15 (Jak1, Jak3, STAT3, and STAT5) were assessed with IL-15 stimulation. IL-15 stimulated glucose uptake and GLUT4 translocation to the plasma membrane. IL-15 treatment had no effect on phospho-Akt, phospho-Akt substrates, phospho-AMPK, phospho-Jak1, or phospho-STAT5. However, with IL-15, phospho-Jak3 and phospho-STAT3 levels were increased along with increased interaction of Jak3 and STAT3. Additionally, IL-15 induced a translocation of phospho-STAT3 from the cytoplasm to the nucleus. We have evidence that a mediator of glucose uptake, HIF1α, expression was dependent on IL-15 induced STAT3 activation. Finally, upon inhibition of STAT3 the positive effects of IL-15 on glucose uptake and GLUT4 translocation were abolished. Taken together, we provide evidence for a novel signaling pathway for IL-15 acting through Jak3/STAT3 to regulate glucose metabolism.
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Affiliation(s)
- James E Krolopp
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman University Orange, CA, USA
| | - Shantaé M Thornton
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman University Orange, CA, USA
| | - Marcia J Abbott
- Department of Health Sciences and Kinesiology, Crean College of Health and Behavioral Sciences, Chapman UniversityOrange, CA, USA; Department of Biological Sciences, Human and Evolutionary Biology Section, Dana and David Dornsife College of Letters, Arts and Sciences, University of Southern CaliforniaLos Angeles, CA, USA
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Palmitic acid interferes with energy metabolism balance by adversely switching the SIRT1-CD36-fatty acid pathway to the PKC zeta-GLUT4-glucose pathway in cardiomyoblasts. J Nutr Biochem 2016; 31:137-49. [DOI: 10.1016/j.jnutbio.2016.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 12/24/2015] [Accepted: 01/06/2016] [Indexed: 12/19/2022]
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Rutaecarpine ameliorates hyperlipidemia and hyperglycemia in fat-fed, streptozotocin-treated rats via regulating the IRS-1/PI3K/Akt and AMPK/ACC2 signaling pathways. Acta Pharmacol Sin 2016; 37:483-96. [PMID: 26972495 DOI: 10.1038/aps.2015.167] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 12/10/2015] [Indexed: 12/28/2022] Open
Abstract
AIM We have shown that rutaecarpine extracted from the dried fruit of Chinese herb Evodia rutaecarpa (Juss) Benth (Wu Zhu Yu) promotes glucose consumption and anti-inflammatory cytokine expression in insulin-resistant primary skeletal muscle cells. In this study we investigated whether rutaecarpine ameliorated the obesity profiles, lipid abnormality, glucose metabolism and insulin resistance in rat model of hyperlipidemia and hyperglycemia. METHODS Rats fed on a high-fat diet for 8 weeks, followed by injection of streptozotocin (30 mg/kg, ip) to induce hyperlipidemia and hyperglycemia. One week after streptozotocin injection, the fat-fed, streptozotocin-treated rats were orally treated with rutaecarpine (25 mg·kg(-1)·d(-1)) or a positive control drug metformin (250 mg·kg(-1)·d(-1)) for 7 weeks. The body weight, visceral fat, blood lipid profiles and glucose levels, insulin sensitivity were measured. Serum levels of inflammatory cytokines were analyzed. IRS-1 and Akt/PKB phosphorylation, PI3K and NF-κB protein levels in liver tissues were assessed; pathological changes of livers and pancreases were examined. Glucose uptake and AMPK/ACC2 phosphorylation were studied in cultured rat skeletal muscle cells in vitro. RESULTS Administration of rutaecarpine or metformin significantly decreased obesity, visceral fat accumulation, water consumption, and serum TC, TG and LDL-cholesterol levels in fat-fed, streptozotocin-treated rats. The two drugs also attenuated hyperglycemia and enhanced insulin sensitivity. Moreover, the two drugs significantly decreased NF-κB protein levels in liver tissues and plasma TNF-α, IL-6, CRP and MCP-1 levels, and ameliorated the pathological changes in livers and pancreases. In addition, the two drugs increased PI3K p85 subunit levels and Akt/PKB phosphorylation, but decreased IRS-1 phosphorylation in liver tissues. Treatment of cultured skeletal muscle cells with rutaecarpine (20-180 μmol/L) or metformin (20 μmol/L) promoted the phosphorylation of AMPK and ACC2, and increased glucose uptake. CONCLUSION Rutaecarpine ameliorates hyperlipidemia and hyperglycemia in fat-fed, streptozotocin-treated rats via regulating IRS-1/PI3K/Akt signaling pathway in liver and AMPK/ACC2 signaling pathway in skeletal muscles.
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Cheng F, Zhao L, Wu Y, Huang T, Yang G, Zhang Z, Wu Y, Jia F, Wu J, Chen C, Liu D. Serum vascular endothelial growth factor B is elevated in women with polycystic ovary syndrome and can be decreased with metformin treatment. Clin Endocrinol (Oxf) 2016; 84:386-93. [PMID: 26387747 DOI: 10.1111/cen.12950] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/21/2015] [Accepted: 09/15/2015] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To determine serum vascular endothelial growth factor B (VEGF-B) levels in polycystic ovary syndrome, their association with insulin resistance and β-cell dysfunction, and the effect of metformin on serum VEGF-B levels. DESIGN A cross-sectional, interventional study. PATIENTS We recruited 103 women with polycystic ovary syndrome and 96 age-matched healthy controls. Serum VEGF-B levels were determined in all participants, and 44 polycystic ovary syndrome patients randomly received metformin. MEASUREMENTS We measured VEGF-B levels in healthy controls and women with polycystic ovary syndrome before and after metformin treatment. RESULTS Women with polycystic ovary syndrome had higher serum VEGF-B levels, which decreased with metformin treatment. In the lean and overweight/obese groups, patients with polycystic ovary syndrome had higher plasma VEGF-B levels than did healthy controls (P < 0·05). VEGF-B levels were correlated with body mass index, body fat percentage, M values, homeostasis model assessment of insulin resistance and β-cell function indices. A multiple linear regression analysis showed that VEGF-B level was associated with M values after adjusting for age, body mass index, serum sex hormones and serum lipids in women with polycystic ovary syndrome. CONCLUSIONS Serum VEGF-B is significantly higher in women with polycystic ovary syndrome and is closely and positively related to insulin resistance. Metformin treatment reduces VEGF-B levels and ameliorates insulin resistance.
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Affiliation(s)
- Feifei Cheng
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lu Zhao
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuanyuan Wu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Tiantian Huang
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Gangyi Yang
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhanyu Zhang
- Department of Gynaecology and Obstetrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yijia Wu
- Department of Gynaecology and Obstetrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Fang Jia
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jinlin Wu
- Department of Endocrinology and Metabolism, Chongqing Traditional Chinese Medicine Hospital, Chongqing, China
| | - Chen Chen
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Dongfang Liu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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Chen YP, Tsai CW, Hsieh DJY, Shen CY, Ho TJ, Padma VV, Kuo WW, Huang CY. Tetramethylpyrazine (TMP) switches energy signalling from the PKCζ-GLUT4-glucose pathway back to the SIRT1-CD36-fatty acid pathway similar to resveratrol to ameliorate cardiac myocyte lipotoxicity. J Funct Foods 2015. [DOI: 10.1016/j.jff.2015.09.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
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21
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Yu R, Zhang ZQ, Wang B, Jiang HX, Cheng L, Shen LM. Berberine-induced apoptotic and autophagic death of HepG2 cells requires AMPK activation. Cancer Cell Int 2014; 14:49. [PMID: 24991192 PMCID: PMC4079188 DOI: 10.1186/1475-2867-14-49] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 04/28/2014] [Indexed: 12/23/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC), the primary liver cancer, is one of the most malignant human tumors with extremely poor prognosis. The aim of this study was to investigate the anti-cancer effect of berberine in a human hepatocellular carcinoma cell line (HepG2), and to study the underlying mechanisms by focusing on the AMP-activated protein kinase (AMPK) signaling cascade. Results We found that berberine induced both apoptotic and autophagic death of HepG2 cells, which was associated with a significant activation of AMPK and an increased expression of the inactive form of acetyl-CoA carboxylase (ACC). Inhibition of AMPK by RNA interference (RNAi) or by its inhibitor compound C suppressed berberine-induced caspase-3 cleavage, apoptosis and autophagy in HepG2 cells, while AICAR, the AMPK activator, possessed strong cytotoxic effects. In HepG2 cells, mammalian target of rapamycin complex 1 (mTORC1) activation was important for cell survival, and berberine inhibited mTORC1 via AMPK activation. Conclusions Together, these results suggested that berberine-induced both apoptotic and autophagic death requires AMPK activation in HepG2 cells.
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Affiliation(s)
- Rong Yu
- Department of Oncology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China ; Department of Interventional Radiology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Zhi-Qing Zhang
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Bin Wang
- Department of Oncology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Hong-Xin Jiang
- Department of Oncology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Lei Cheng
- Department of Interventional Radiology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Li-Ming Shen
- Department of Interventional Radiology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
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22
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Kristensen JM, Treebak JT, Schjerling P, Goodyear L, Wojtaszewski JFP. Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle. Am J Physiol Endocrinol Metab 2014; 306:E1099-109. [PMID: 24644243 PMCID: PMC4971810 DOI: 10.1152/ajpendo.00417.2013] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metformin-induced activation of the 5'-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P < 0.01) but not of AMPK KD mice. Insulin signaling at the level of Akt protein expression or Thr(308) and Ser(473) phosphorylation was not changed by metformin treatment. Insulin signaling at the level of Akt and TBC1D4 protein expression as well as Akt Thr(308)/Ser(473) and TBC1D4 Thr(642)/Ser(711) phosphorylation were not changed by metformin treatment. Also, protein expressions of Rab4, GLUT4, and hexokinase II were unaltered after treatment. The acute metformin treatment did not affect glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment.
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Affiliation(s)
- Jonas Møller Kristensen
- Molecular Physiology Group, August Krogh Centre, Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonas T Treebak
- Molecular Physiology Group, August Krogh Centre, Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; and
| | - Laurie Goodyear
- Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Jørgen F P Wojtaszewski
- Molecular Physiology Group, August Krogh Centre, Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark;
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Towler DA. Mitochondrial ROS deficiency and diabetic complications: AMP[K]-lifying the adaptation to hyperglycemia. J Clin Invest 2013; 123:4573-6. [PMID: 24135143 DOI: 10.1172/jci72326] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Global, sustained production of ROS has deleterious effects on tissue structure and function and gives rise to biochemical and physiological changes associated with organ senescence. Specific, localized ROS metabolites generated by mitochondria and NADPH oxidases also transduce homeostatic information in response to metabolic, mechanical, and inflammatory cues. In this issue of the JCI, Dugan and colleagues demonstrate that mitochondrial-derived ROS, which is maintained by a feed-forward AMP kinase activation cascade, is reduced in diabetes and plays an adaptive role in preserving renal glomerular function during hyperglycemia. This enlightened view of mitochondrial ROS biology forces us to reconsider therapeutic approaches to metabolic disease complications such as diabetic nephropathy.
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Ying H, Wang Z, Zhang Y, Yang TY, Ding ZH, Liu SY, Shao J, Liu Y, Fan XB. Capsaicin induces apoptosis in human osteosarcoma cells through AMPK-dependent and AMPK-independent signaling pathways. Mol Cell Biochem 2013; 384:229-37. [PMID: 24005536 DOI: 10.1007/s11010-013-1802-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/23/2013] [Indexed: 12/25/2022]
Abstract
Recent studies have focused on the anti-tumor activity of capsaicin. However, the potential effects of capsaicin in osteosarcoma cells and the underlying mechanisms are not fully understood. In the current study, we observed that capsaicin-induced growth inhibition and apoptosis in cultured osteosarcoma cells (U2OS and MG63), which were associated with a significant AMP-activated protein kinase (AMPK) activation. AMPK inhibition by compound C or RNA interference suppressed capsaicin-induced cytotoxicity, while AMPK activators (AICAR and A769662) promoted osteosarcoma cell death. For the mechanism study, we found that AMPK activation was required for capsaicin-induced mTORC1 (mTOR complex 1) inhibition, B cell lymphoma 2 (Bcl-2) downregulation and Bax upregulation in MG63 cells. Capsaicin administration induced p53 activation, mitochondrial translocation and Bcl-2 killer association, such effects were dependent on AMPK activation. Interestingly, we observed a significant pro-apoptotic c-Jun NH2-terminal kinases activation by capsaicin in MG63 cells, which appeared to be AMPK independent. In conclusion, capsaicin possessed strong efficacy against human osteosarcoma cells. Molecular studies revealed that capsaicin activated AMPK-dependent and AMPK-independent signalings to mediate cell apoptosis. The results of this study should have significant translational relevance in managing this deadly malignancy.
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Affiliation(s)
- Hui Ying
- Department of Orthopedics, Gongli Hospital of Pudong New District, No. 219, Miaopu Road, Pudong New District, Shanghai, 200135, China
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Zhang TX, Xu JX, Peng F, Chai DJ, Lin JX. Metformin reduces vascular endothelial dysfunction caused by an acute glucose load in patients with hypertension. Blood Press 2012; 22:106-13. [DOI: 10.3109/08037051.2012.732761] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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26
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Turcotte LP, Abbott MJ. Contraction-induced signaling: evidence of convergent cascades in the regulation of muscle fatty acid metabolism. Can J Physiol Pharmacol 2012. [PMID: 23181271 DOI: 10.1139/y2012-124] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The regulation of fatty acid utilization during muscle contraction and exercise remains to be fully elucidated. Evidence suggests that the metabolic responses of skeletal muscle induced by the contraction-induced changes in energy demand are mediated by the activation of a multitude of intracellular signaling cascades. This review addresses the roles played by 3 intracellular signaling cascades of interest in the regulation of fatty acid uptake and oxidation in contracting skeletal muscle; namely, the AMP-activated protein kinase (AMPK), calcium/calmodulin-dependent protein kinases (CaMKs), and the extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling cascades. Data delineating the potential role of AMPK in cross-talk with CaMKII, CaMK kinase (CaMKK), and ERK1/2 are presented. Collectively, data show that in perfused rodent muscle, regulation of fatty acid uptake and oxidation occurs via (i) CaMKII signaling via both AMPK-dependent and -independent cascades, (ii) CaMKK signaling via both AMPK-dependent and -independent cascades, (iii) AMPK signaling in a time- and intensity-dependent manner, and (iv) ERK1/2 signaling in an intensity-dependent manner.
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Affiliation(s)
- Lorraine P Turcotte
- Department of Biological Sciences, Dana and David Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089-0652, USA.
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Constantinescu S, Turcotte LP. Genetic downregulation of receptor-interacting protein 140 uncovers the central role of Akt signalling in the regulation of fatty acid oxidation in skeletal muscle cells. Exp Physiol 2012; 98:514-25. [DOI: 10.1113/expphysiol.2012.068833] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Perspectives on translational and therapeutic aspects of SIRT1 in inflammaging and senescence. Biochem Pharmacol 2012; 84:1332-9. [PMID: 22796566 DOI: 10.1016/j.bcp.2012.06.031] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 02/08/2023]
Abstract
Sirtuin1 (SIRT1), a type III protein deacetylase, is considered as a novel anti-aging protein involved in regulation of cellular senescence/aging and inflammation. SIRT1 level and activity are decreased during lung inflammaging caused by oxidative stress. The mechanism of SIRT1-mediated protection against inflammaging is associated with the regulation of inflammation, premature senescence, telomere attrition, senescence associated secretory phenotype, and DNA damage response. A variety of dietary polyphenols and pharmacological activators are shown to regulate SIRT1 so as to intervene the progression of type 2 diabetes, cancer, cardiovascular diseases, and chronic obstructive pulmonary disease associated with inflammaging. However, recent studies have shown the non-specific regulation of SIRT1 by the aforementioned pharmacological activators and polyphenols. In this perspective, we have briefly discussed the role of SIRT1 in regulation of cellular senescence and its associated secretory phenotype, DNA damage response, particularly in lung inflammaging and during the development of chronic obstructive pulmonary diseases. We have also discussed the potential directions for future translational therapeutic avenues for SIRT1 in modulating lung inflammaging associated with senescence in chronic lung diseases associated with increased oxidative stress.
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Turban S, Stretton C, Drouin O, Green CJ, Watson ML, Gray A, Ross F, Lantier L, Viollet B, Hardie DG, Marette A, Hundal HS. Defining the contribution of AMP-activated protein kinase (AMPK) and protein kinase C (PKC) in regulation of glucose uptake by metformin in skeletal muscle cells. J Biol Chem 2012; 287:20088-99. [PMID: 22511782 PMCID: PMC3370192 DOI: 10.1074/jbc.m111.330746] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 04/11/2012] [Indexed: 12/25/2022] Open
Abstract
The importance of AMP-activated protein kinase (AMPK) and protein kinase C (PKC) as effectors of metformin (Met) action on glucose uptake (GU) in skeletal muscle cells was investigated. GU in L6 myotubes was stimulated 2-fold following 16 h of Met treatment and acutely enhanced by insulin in an additive fashion. Insulin-stimulated GU was sensitive to PI3K inhibition, whereas that induced by Met was not. Met and its related biguanide, phenformin, stimulated AMPK activation/phosphorylation to a level comparable with that induced by the AMPK activator, 5-amino-1-β-d-ribofuranosyl-imidazole-4-carboxamide (AICAR). However, the increase in GU elicited by AICAR was significantly lower than that induced by either biguanide. Expression of a constitutively active AMPK mimicked the effects of AICAR on GU, whereas a dominant interfering AMPK or shRNA silencing of AMPK prevented AICAR-stimulated GU and Met-induced AMPK signaling but only repressed biguanide-stimulated GU by ∼20%. Consistent with this, analysis of GU in muscle cells from α1(-/-)/α2(-/-) AMPK-deficient mice revealed a significant retention of Met-stimulated GU, being reduced by ∼35% compared with that of wild type cells. Atypical PKCs (aPKCs) have been implicated in Met-stimulated GU, and in line with this, Met and phenformin induced activation/phosphorylation of aPKC in L6 myotubes. However, although cellular depletion of aPKC (>90%) led to loss in biguanide-induced aPKC phosphorylation, it had no effect on Met-stimulated GU, whereas inhibitors targeting novel/conventional PKCs caused a significant reduction in biguanide-induced GU. Our findings indicate that although Met activates AMPK, a significant component of Met-stimulated GU in muscle cells is mediated via an AMPK-independent mechanism that involves novel/conventional PKCs.
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Affiliation(s)
- Sophie Turban
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Clare Stretton
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Olivier Drouin
- the Department of Medicine, Québec Heart and Lung Institute, Université Laval and Metabolism, Vascular, and Renal Health Axis, Laval University Hospital Research Center, Ste-Foy, Québec, G1V 4G2, Canada
| | - Charlotte J. Green
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Maria L. Watson
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Alexander Gray
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Fiona Ross
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Louise Lantier
- INSERM, Institut Cochin, U1016, Paris, France
- CNRS, UMR8104, Paris, France, and
- Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - Benoit Viollet
- INSERM, Institut Cochin, U1016, Paris, France
- CNRS, UMR8104, Paris, France, and
- Université Paris Descartes, Sorbonne Paris Cité, 75014 Paris, France
| | - D. Grahame Hardie
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Andre Marette
- the Department of Medicine, Québec Heart and Lung Institute, Université Laval and Metabolism, Vascular, and Renal Health Axis, Laval University Hospital Research Center, Ste-Foy, Québec, G1V 4G2, Canada
| | - Harinder S. Hundal
- From the Division of Cell Signaling and Immunology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
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Rahman I, Kinnula VL, Gorbunova V, Yao H. SIRT1 as a therapeutic target in inflammaging of the pulmonary disease. Prev Med 2012; 54 Suppl:S20-8. [PMID: 22178470 PMCID: PMC3311735 DOI: 10.1016/j.ypmed.2011.11.014] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 11/30/2011] [Indexed: 10/14/2022]
Abstract
OBJECTIVE Chronic inflammation and cellular senescence are intertwined in the pathogenesis of premature aging, which is considered as an important contributing factor in driving chronic obstructive pulmonary disease (COPD). Sirtuin1 (SIRT1), a nicotinamide adenine dinucleotide (NAD(+))-dependent protein/histone deacetylase, regulates inflammation, senescence/aging, stress resistance, and deoxyribonucleic acid (DNA) damage repair via deacetylating intracellular signaling molecules and chromatin histones. The present review describes the mechanism and regulation of SIRT1 by environmental agents/oxidants/reactive aldehydes and pro-inflammatory stimuli in lung inflammation and aging. The role of dietary polyphenols in regulation of SIRT1 in inflammaging is also discussed. METHODS Analysis of current research findings on the mechanism of inflammation and senescence/aging (i.e., inflammaging) and their regulation by SIRT1 in premature aging of the lung. RESULTS COPD is a disease of the lung inflammaging, which is associated with the DNA damage response, transcription activation and chromatin modifications. SIRT1 regulates inflammaging via regulating forkhead box class O 3, p53, nuclear factor kappa B, histones and various proteins involved in DNA damage and repair. Polyphenols and its analogs have been shown to activate SIRT1 although they have anti-inflammatory and antioxidant properties. CONCLUSIONS Targeting lung inflammation and cellular senescence as well as premature lung aging using pharmacological SIRT1 activators or polyphenols would be a promising therapeutic intervention for COPD/emphysema.
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Affiliation(s)
- Irfan Rahman
- Department of Environmental Medicine, Lung Biology and Disease Program, University of Rochester Medical Center, Rochester, NY 14642, USA.
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Pinter K, Jefferson A, Czibik G, Watkins H, Redwood C. Subunit composition of AMPK trimers present in the cytokinetic apparatus: Implications for drug target identification. Cell Cycle 2012; 11:917-21. [PMID: 22333580 DOI: 10.4161/cc.11.5.19412] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AMP-activated protein kinase has been shown to be a key regulator of energy homeostasis; it has also been identified as a tumor suppressor and is required for correct cell division and chromosome segregation during mitosis. The enzyme is a heterotrimer, with each subunit having more than one isoform, each encoded by a separate gene (two α, two β and three γ isoforms). In human endothelial cells, the activated kinase subunit of AMPK in the cytokinetic apparatus is α2, the minority α subunit, which co-localizes with β2 and γ2. This is the first demonstration of a trimeric complex of AMPK containing the γ2 regulatory subunit becoming selectively activated and being linked to mitotic processes. We also show that α1 and γ1, the predominant AMPK subunits, are almost exclusively localized in the cytoskeleton, while α2 and γ2 are present in all subcellular fractions, including the nuclei. These data suggest that pharmacological interventions targeted to specific AMPK subunit isoforms have the potential to modify selective functions of AMPK.
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Affiliation(s)
- Katalin Pinter
- Department of Cardiovascular Medicine, University of Oxford, West Wing Level 6, John Radcliffe Hospital, Oxford, United Kingdom
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32
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Bogachus LD, Turcotte LP. HIV protease inhibitors induce metabolic dysfunction in part via increased JNK1/2 pro-inflammatory signaling in L6 cells. Antiviral Res 2011; 92:415-23. [PMID: 21968131 DOI: 10.1016/j.antiviral.2011.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 08/31/2011] [Accepted: 09/16/2011] [Indexed: 01/22/2023]
Abstract
Protease inhibitors (PIs), such as atazanavir sulfate and ritonavir, are used clinically to prevent the progression of HIV and are known to induce insulin resistance. To determine whether PI-mediated insulin resistance is induced by activation of pro-inflammatory cascades, L6 skeletal muscle cells were treated ±atazanavir sulfate, ritonavir, or atazanavir sulfate + ritonavir, and ±insulin. Treatment with atazanavir sulfate, ritonavir, or atazanavir sulfate + ritonavir for 24 or 48 h significantly increased basal glucose uptake (P<0.05) and atazanavir sulfate + ritonavir treatment increased basal glucose uptake significantly more than ritonavir or atazanavir sulfate treatment alone (P<0.05). Atazanavir sulfate + ritonavir treatment for 48 h completely prevented insulin stimulation of glucose uptake (P>0.05). When compared to untreated cells, basal palmitate uptake and oxidation was found to be significantly higher in cells treated with PIs alone or in combination (P<0.05). Prior PI treatment alone or in combination prevented (P>0.05) the insulin-mediated increase in palmitate uptake and the insulin-mediated decrease in palmitate oxidation observed in the control group. Atazanavir sulfate treatment alone or in combination with ritonavir significantly increased JNK1/2 phosphorylation when compared to the control or ritonavir group (P<0.05) and this was accompanied by a rise (P<0.05) in AKT(Ser473) phosphorylation in the basal state. Total JNK1/2 and p38 MAPK protein content and p38 MAPK phosphorylation state were not altered in any of the treatment groups (P>0.05). Our data indicate that, in muscle cells, PIs induce metabolic dysfunction that is not limited to insulin-sensitive metabolism and that is potentially mediated by a rise in JNK1/2 pro-inflammatory signaling.
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Affiliation(s)
- Lindsey D Bogachus
- Department of Biological Sciences, Dana and David Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, 90089-0652, USA
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Abstract
Thyroid disease and type 1 but also type 2 diabetes mellitus (DM) are strongly associated, and this has important clinical implications for insulin sensitivity and treatment requirements. The pathophysiological basis of this association has only recently been better elucidated. It rests on a complex interaction of common signalling pathways and, in the case of type 1 diabetes and autoimmune thyroid disease, on a linked genetic susceptibility. The pathophysiological mechanisms underlying this linked regulation are increasingly being unravelled. They are exemplified in the regulation of 5' adenosine monophosphate-activated protein kinase (AMPK), a central target not only for the modulation of insulin sensitivity but also for the feedback of thyroid hormones on appetite and energy expenditure. The present review will discuss these concepts and their consequences for the clinical care of patients with DM and thyroid disorders. Moreover, it makes reference to the added effect of metformin in suppressing TSH.
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Affiliation(s)
- Leonidas H Duntas
- Endocrine Unit, Evgenidion Hospital, University of Athens Medical School, Athens, GreeceService d' Endocrinologie-Diabète-Maladies Métaboliques, Centre Hospitalier, Lyon-Sud, FranceDepartment of Endocrinology, The Christie, Manchester Academic Health Science Centre, Manchester, UK
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