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Pandey S, Tuma Z, Smrhova T, Cedikova M, Macanova T, Chottova Dvorakova M. Laser Capture Microdissection Coupled Capillary Immunoassay to Study the Expression of PCK-2 on Spatially-Resolved Islets of Rat Langerhans. Pharmaceutics 2021; 13:pharmaceutics13060883. [PMID: 34203686 PMCID: PMC8232303 DOI: 10.3390/pharmaceutics13060883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/02/2021] [Accepted: 06/09/2021] [Indexed: 11/25/2022] Open
Abstract
The platform for precise proteomic profiling of targeted cell populations from heterogeneous tissue sections is developed. We demonstrate a seamless and systematic integration of LCM with an automated cap-IA for the handling of a very small-sized dissected tissues section from the kidney, liver and pancreatic Langerhans islet of rats. Our analysis reveals that the lowest LCM section area ≥ 0.125 mm2 with 10 µm thickness can be optimized for the detection of proteins through LCM-cap-IA integration. We detect signals ranging from a highly-abundant protein, β-actin, to a low-abundance protein, LC-3AB, using 0.125 mm2 LCM section from rat kidney, but, so far, a relatively large section is required for good quality of results. This integration is applicable for a highly-sensitive and accurate assessment of microdissected tissue sections to decipher hidden proteomic information of pure targeted cells. To validate this integration, PCK2 protein expression is studied within Langerhans islets of normal and diabetic rats. Our results show significant overexpression of PCK2 in Langerhans islets of rats with long-term diabetes.
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Affiliation(s)
- Shashank Pandey
- Department of Pharmacology and Toxicology, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic
- Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic; (Z.T.); (M.C.); (M.C.D.)
- Correspondence:
| | - Zdenek Tuma
- Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic; (Z.T.); (M.C.); (M.C.D.)
| | - Tereza Smrhova
- Department of Physiology, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic;
| | - Miroslava Cedikova
- Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic; (Z.T.); (M.C.); (M.C.D.)
- Department of Physiology, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic;
| | - Tereza Macanova
- Department of Biology, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic;
| | - Magdalena Chottova Dvorakova
- Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic; (Z.T.); (M.C.); (M.C.D.)
- Department of Physiology, Faculty of Medicine in Pilsen, Charles University, Alej Svobody 1655/76, 32300 Pilsen, Czech Republic;
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Wang SY, Wu SL, Chen TC, Chuang CS. Antidiabetic Agents for Treatment of Parkinson's Disease: A Meta-Analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17134805. [PMID: 32635358 PMCID: PMC7369739 DOI: 10.3390/ijerph17134805] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 02/07/2023]
Abstract
Background: Clinical and epidemiological studies suggest that two of the most common geriatric diseases, type 2 diabetes and Parkinson’s disease (PD), are linked. These studies notably suggest that treatment of insulin resistance in type 2 diabetes may beneficially modify the pathophysiology of PD and help to maintain motor and nonmotor function. In this meta-analysis, we evaluate the efficacy of new antidiabetic agents in the treatment of PD. Methods: We systematically searched PubMed, Medline, ProQuest, ScienceDirect, ClinicalKey, and Cochrane Library from the date of their inception until 15 March 2020. Multiple efficacy parameters were compared between treatment groups. The results are expressed as mean differences with 95% confidence intervals (CIs) in a random-effects model. Results: A meta-analysis of the data extracted from three randomized control trials revealed that treatment with exenatide yielded significant improvements in scores on the Unified Parkinson’s Disease Rating Scale Part I (UPDRS-I) (−0.438, 95% CI, −0.828 to −0.048, p = 0.028), UPDRS Part IV (UPDRS-IV) (−0.421, 95% CI, −0.811 to −0.032, p = 0.034) and the Mattis Dementia Rating Scale (MDRS) (−0.595, 95% CI, −1.038 to −0.151, p = 0.009). At the 12-month follow-up, the UPDRS Part III (UPDRS-III) scores in the off-medication phase revealed significant improvements in patients using exenatide (−0.729; 95% CI, −1.233 to −0.225, p = 0.005). Treatment with pioglitazone did not yield significant improvements in UPDRS, MDRS, or Parkinson’s Disease Questionnaire scores. Conclusion: This meta-analysis suggests that exenatide use is associated with the alleviation of cognitive, motor and nonmotor symptoms. However, long-term studies with a large sample size of patients with PD of varying severity are required.
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Affiliation(s)
- Shu-Yi Wang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Changhua Christian Hospital, Changhua 500209, Taiwan;
| | - Shey-Lin Wu
- Department of Neurology, Changhua Christian Hospital, Changhua 500209, Taiwan; (S.-L.W.); (T.-C.C.)
| | - Ta-Cheng Chen
- Department of Neurology, Changhua Christian Hospital, Changhua 500209, Taiwan; (S.-L.W.); (T.-C.C.)
| | - Chieh-Sen Chuang
- Department of Neurology, Changhua Christian Hospital, Changhua 500209, Taiwan; (S.-L.W.); (T.-C.C.)
- College of Medicine, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
- Correspondence: ; Tel.: +88-64-723-8595
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Modification by Ethanol and Taurine, Singly and in Combination, of Changes in Indices of Renal Dysfunction Caused by Diabetes in Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1155:369-380. [DOI: 10.1007/978-981-13-8023-5_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Ericsson A, Tonelius P, Lal M, Sabirsh A, Böttcher G, William-Olsson L, Strömstedt M, Johansson C, Hyberg G, Tapani S, Jönsson-Rylander AC, Unwin R. The effects of dual PPAR α/ γ agonism compared with ACE inhibition in the BTBRob/ob mouse model of diabetes and diabetic nephropathy. Physiol Rep 2017; 5:5/5/e13186. [PMID: 28292877 PMCID: PMC5350186 DOI: 10.14814/phy2.13186] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 01/31/2017] [Accepted: 02/05/2017] [Indexed: 02/06/2023] Open
Abstract
The leptin‐deficient BTBRob/ob mouse develops progressive albuminuria and morphological lesions similar to human diabetic nephropathy (DN), although whether glomerular hyperfiltration, a recognized feature of early DN that may contribute to renal injury, also occurs in this model is not known. Leptin replacement has been shown to reverse the signs of renal injury in this model, but in contrast, the expected renoprotection by angiotensin‐converting enzyme (ACE) inhibition in BTBRob/ob mice seems to be limited. Therefore, to investigate the potential renal benefits of improved metabolic control in this model, we studied the effect of treatment with the dual peroxisome proliferator‐activated receptor (PPAR) α/γ agonist AZD6610 and compared it with the ACE inhibitor enalapril. AZD6610 lowered plasma glucose and triglyceride concentrations and increased liver size, but had no significant effect in reducing albuminuria, whereas enalapril did have an effect. Nephrin and WT1 mRNA expression decreased in the kidneys of BTBRob/ob mice, consistent with podocyte injury and loss, but was unaffected by either drug treatment: at the protein level, both nephrin and WT1‐positive cells per glomerulus were decreased. Mesangial matrix expansion was reduced in AZD6610‐treated mice. GFR, measured by creatinine clearance, was increased in BTBRob/ob mice, but unaffected by either treatment. Unexpectedly, enalapril‐treated mice showed intrarenal arteriolar vascular remodeling with concentric thickening of vessel walls. In summary, we found that the BTBRob/ob mouse model shows some similarities to the early changes seen in human DN, but that ACE inhibition or PPARα/γ agonism afforded limited or no kidney protection.
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Affiliation(s)
- Anette Ericsson
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Pernilla Tonelius
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Mark Lal
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Alan Sabirsh
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Gerhard Böttcher
- Drug, Safety & Metabolism, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Lena William-Olsson
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Maria Strömstedt
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Camilla Johansson
- Drug, Safety & Metabolism, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Gina Hyberg
- Drug, Safety & Metabolism, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Sofia Tapani
- Discovery Sciences Innovative Medicines Research Unit, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | | | - Robert Unwin
- Cardiovascular & Metabolic Disease Innovative Medicines, AstraZeneca R&D Gothenburg, Mölndal, Sweden
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Liu L, Zhou M, Lang H, Zhou Y, Mi M. Dihydromyricetin enhances glucose uptake by inhibition of MEK/ERK pathway and consequent down-regulation of phosphorylation of PPARγ in 3T3-L1 cells. J Cell Mol Med 2017; 22:1247-1256. [PMID: 29160030 PMCID: PMC5783835 DOI: 10.1111/jcmm.13403] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/01/2017] [Indexed: 12/16/2022] Open
Abstract
Accumulating evidence suggests that inhibition of mitogen-activated protein kinase signalling can reduce phosphorylation of peroxisome proliferator-activated receptor γ (PPARγ) at serine 273, which mitigates obesity-associated insulin resistance and might be a promising treatment for type 2 diabetes. Dihydromyricetin (DHM) is a flavonoid that has many beneficial pharmacological properties. In this study, mouse fibroblast 3T3-L1 cells were used to investigate whether DHM alleviates insulin resistance by inhibiting PPARγ phosphorylation at serine 273 via the MEK/ERK pathway. 3T3-L1 pre-adipocytes were differentiated, and the effects of DHM on adipogenesis and glucose uptake in the resulting adipocytes were examined. DHM was found to dose dependently increase glucose uptake and decrease adipogenesis. Insulin resistance was then induced in adipocytes using dexamethasone, and DHM was shown to dose and time dependently promote glucose uptake in the dexamethasone-treated adipocytes. DHM also inhibited phosphorylation of PPARγ and ERK. Inhibition of PPARγ activity with GW9662 potently blocked DHM-induced glucose uptake and adiponectin secretion. Interestingly, DHM showed similar effects to PD98059, an inhibitor of the MEK/ERK pathway. DHM acted synergistically with PD98059 to improve glucose uptake and adiponectin secretion in dexamethasone-treated adipocytes. In conclusion, our findings indicate that DHM improves glucose uptake in adipocytes by inhibiting ERK-induced phosphorylation of PPARγ at serine 273.
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Affiliation(s)
- Lei Liu
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Min Zhou
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Hedong Lang
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China
| | - Yong Zhou
- Department of Clinic Nutrition, People's Hospital of Chongqing Banan District, Chongqing, China
| | - Mantian Mi
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China
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Trevaskis JL, Sacramento CB, Jouihan H, Ali S, Le Lay J, Oldham S, Bhagroo N, Boland BB, Cann J, Chang Y, O'Day T, Howard V, Reers C, Winzell MS, Smith DM, Feigh M, Barkholt P, Schreiter K, Austen M, Andag U, Thompson S, Jermutus L, Coghlan MP, Grimsby J, Dohrmann C, Rhodes CJ, Rondinone CM, Sharma A. Neurturin and a GLP-1 Analogue Act Synergistically to Alleviate Diabetes in Zucker Diabetic Fatty Rats. Diabetes 2017; 66:2007-2018. [PMID: 28408435 DOI: 10.2337/db16-0916] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 04/05/2017] [Indexed: 11/13/2022]
Abstract
Neurturin (NRTN), a member of the glial-derived neurotrophic factor family, was identified from an embryonic chicken pancreatic cDNA library in a screen for secreted factors. In this study, we assessed the potential antidiabetic activities of NRTN relative to liraglutide, a glucagon-like peptide 1 receptor agonist, in Zucker diabetic fatty (ZDF) rats. Subcutaneous administration of NRTN to 8-week-old male ZDF rats prevented the development of hyperglycemia and improved metabolic parameters similar to liraglutide. NRTN treatment increased pancreatic insulin content and β-cell mass and prevented deterioration of islet organization. However, unlike liraglutide-treated rats, NRTN-mediated improvements were not associated with reduced body weight or food intake. Acute NRTN treatment did not activate c-Fos expression in key feeding behavior and metabolic centers in ZDF rat brain or directly enhance glucose-stimulated insulin secretion from pancreatic β-cells. Treating 10-week-old ZDF rats with sustained hyperglycemia with liraglutide resulted in some alleviation of hyperglycemia, whereas NRTN was not as effective despite improving plasma lipids and fasting glucose levels. Interestingly, coadministration of NRTN and liraglutide normalized hyperglycemia and other metabolic parameters, demonstrating that combining therapies with distinct mechanism(s) can alleviate advanced diabetes. This emphasizes that therapeutic combinations can be more effective to manage diabetes in individuals with uncontrolled hyperglycemia.
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Affiliation(s)
- James L Trevaskis
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | | | - Hani Jouihan
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Safina Ali
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - John Le Lay
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Stephanie Oldham
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Nicholas Bhagroo
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Brandon B Boland
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Jennifer Cann
- Translational Sciences (Pathology), MedImmune LLC, Gaithersburg, MD
| | - Yuan Chang
- Biopharmaceutical Development, MedImmune LLC, Gaithersburg, MD
| | | | - Victor Howard
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | | | | | - David M Smith
- Discovery Sciences, Innovative Medicines & Early Development Biotech Unit, AstraZeneca, Cambridge, U.K
| | | | | | | | | | | | - Simon Thompson
- Research Project and Portfolio Management, MedImmune Ltd., Cambridge, U.K
| | - Lutz Jermutus
- Department of Cardiovascular and Metabolic Diseases, MedImmune Ltd., Cambridge, U.K
| | - Matthew P Coghlan
- Department of Cardiovascular and Metabolic Diseases, MedImmune Ltd., Cambridge, U.K
| | - Joseph Grimsby
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | | | - Christopher J Rhodes
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Cristina M Rondinone
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
| | - Arun Sharma
- Department of Cardiovascular and Metabolic Diseases, MedImmune LLC, Gaithersburg, MD
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7
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Bae KH, Seo JB, Jung YA, Seo HY, Kang SH, Jeon HJ, Lee JM, Lee S, Kim JG, Lee IK, Jung GS, Park KG. Lobeglitazone, a Novel Peroxisome Proliferator-Activated Receptor γ Agonist, Attenuates Renal Fibrosis Caused by Unilateral Ureteral Obstruction in Mice. Endocrinol Metab (Seoul) 2017; 32:115-123. [PMID: 28256116 PMCID: PMC5368110 DOI: 10.3803/enm.2017.32.1.115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/12/2017] [Accepted: 01/16/2017] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Renal tubulointerstitial fibrosis is a common feature of the final stage of nearly all cause types of chronic kidney disease. Although classic peroxisome proliferator-activated receptor γ (PPARγ) agonists have a protective effect on diabetic nephropathy, much less is known about their direct effects in renal fibrosis. This study aimed to investigate possible beneficial effects of lobeglitazone, a novel PPARγ agonist, on renal fibrosis in mice. METHODS We examined the effects of lobeglitazone on renal tubulointerstitial fibrosis in unilateral ureteral obstruction (UUO) induced renal fibrosis mice. We further defined the role of lobeglitazone on transforming growth factor (TGF)-signaling pathways in renal tubulointerstitial fibrosis through in vivo and in vitro study. RESULTS Through hematoxylin/eosin and sirius red staining, we observed that lobeglitazone effectively attenuates UUO-induced renal atrophy and fibrosis. Immunohistochemical analysis in conjunction with quantitative reverse transcription polymerase chain reaction and Western blot analysis revealed that lobeglitazone treatment inhibited UUO-induced upregulation of renal Smad-3 phosphorylation, α-smooth muscle actin, plasminogen activator inhibitor 1, and type 1 collagen. In vitro experiments with rat mesangial cells and NRK-49F renal fibroblast cells suggested that the effects of lobeglitazone on UUO-induced renal fibrosis are mediated by inhibition of the TGF-β/Smad signaling pathway. CONCLUSION The present study demonstrates that lobeglitazone has a protective effect on UUO-induced renal fibrosis, suggesting that its clinical applications could extend to the treatment of non-diabetic origin renal disease.
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Affiliation(s)
- Kwi Hyun Bae
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea
| | - Jung Beom Seo
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
| | - Yun A Jung
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
| | - Hye Young Seo
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
| | - Sun Hee Kang
- Department of Surgery, Keimyung University School of Medicine, Daegu, Korea
| | - Hui Jeon Jeon
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea
| | - Jae Man Lee
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, Kyungpook National University School of Medicine, Daegu, Korea
| | - Sungwoo Lee
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Jung Guk Kim
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
| | - In Kyu Lee
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea
| | - Gwon Soo Jung
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea.
| | - Keun Gyu Park
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu, Korea
- Leading-Edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea.
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Liu L, Wan J, Lang H, Si M, Zhu J, Zhou Y, Mi M. Dihydromyricetin delays the onset of hyperglycemia and ameliorates insulin resistance without excessive weight gain in Zucker diabetic fatty rats. Mol Cell Endocrinol 2017; 439:105-115. [PMID: 27984083 DOI: 10.1016/j.mce.2016.10.028] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 01/23/2023]
Abstract
Many flavonoids are reported to be partial agonists of PPARγ and exert antidiabetic effects with fewer side effects compared with full agonists. Here, we assessed the effects of flavonoid dihydromyricetin (DHM) on glucose homeostasis in male Zucker diabetic fatty rats. Animals were treated with DHM (50-200 mg kg-1) or rosiglitazone (4 mg kg-1) once a day for 8 weeks. We found that DHM reduced fasting blood glucose and delayed the onset of hyperglycemia by 4 weeks. Furthermore, DHM preserved pancreatic β-cell mass, elevated adiponectin and improved lipid profile more vigorously than rosiglitazone. Notably, DHM decreased body weight gain and fat accumulation in both liver and adipose tissue, while rosiglitazone caused a significant increase of body weight and fat accumulation. DHM inhibited phosphorylation of PPARγ at serine 273 more efficiently than rosiglitazone. These results suggest that DHM exerts antidiabetic effects without causing excessive body weight gain via inhibition of PPARγ phosphorylation.
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Affiliation(s)
- Lei Liu
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
| | - Jing Wan
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
| | - Hedong Lang
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
| | - Mingyu Si
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
| | - Jundong Zhu
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
| | - Yong Zhou
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
| | - Mantian Mi
- Research Center for Nutrition and Food Safety, Chongqing Key Laboratory of Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing, China.
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Reynolds MR, Clem BF. Troglitazone suppresses glutamine metabolism through a PPAR-independent mechanism. Biol Chem 2016; 396:937-47. [PMID: 25872876 DOI: 10.1515/hsz-2014-0307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/02/2015] [Indexed: 11/15/2022]
Abstract
Enhanced glutamine metabolism is required for tumor cell growth and survival, which suggests that agents targeting glutaminolysis may have utility within anti-cancer therapies. Troglitazone, a PPARγ agonist, exhibits significant anti-tumor activity and can alter glutamine metabolism in multiple cell types. Therefore, we examined whether troglitazone would disrupt glutamine metabolism in tumor cells and whether its action was reliant on PPARγ activity. We found that troglitazone treatment suppressed glutamine uptake and the expression of the glutamine transporter, ASCT2, and glutaminase. In addition, troglitazone reduced 13C-glutamine incorporation into the TCA cycle, decreased [ATP], and resulted in an increase in reactive oxygen species (ROS). Further, troglitazone treatment decreased tumor cell growth, which was partially rescued with the addition of the TCA-intermediate, α-ketoglutarate, or the antioxidant N-acetylcysteine. Importantly, troglitazone's effects on glutamine uptake or viable cell number were found to be PPARγ-independent. In contrast, troglitazone caused a decrease in c-Myc levels, while the proteasomal inhibitor, MG132, rescued c-Myc, ASCT2 and GLS1 expression, as well as glutamine uptake and cell number. Lastly, combinatorial treatment of troglitazone and metformin resulted in a synergistic decrease in cell number. Therefore, characterizing new anti-tumor properties of previously approved FDA therapies supports the potential for repurposing of these agents.
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Han YH, Kwon SY, Kim J, Na CJ, Choi S, Min JJ, Bom HS, Kim YC, Oh IJ, Chae HJ, Lim ST, Sohn MH, Jeong HJ. A phase II clinical trial to investigate the effect of pioglitazone on (18)F-FDG uptake in malignant lesions. EJNMMI Res 2015; 5:50. [PMID: 26408008 PMCID: PMC4583556 DOI: 10.1186/s13550-015-0128-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/13/2015] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND We found that (18)F-2-fluoro-2-deoxy-D-glucose ((18)F-FDG) uptake in malignant lesion was enhanced, and it was decreased in the inflammatory lesion after the use of peroxisome proliferator activated receptor-γ (PPAR-γ) agonist in our previous preclinical study. The purpose of this study was to investigate the effect of PPAR-γ agonist on malignant lesions in clinical (18)F-FDG positron emission tomography/computed tomography (PET/CT) imaging. METHODS Forty-three patients were enrolled in this prospective study. We received the approval for the investigator-initiated trials for a phase II human clinical trial from the Korean Food and Drug Administration. On the first day, (18)F-FDG PET/CT images were acquired from patients without administration of pioglitazone (PIO), which is a PPAR-γ agonist. On the next day, (18)F-FDG PET/CT images were acquired once again from the same patients after administration of PIO. We measured the (18)F-FDG uptake in malignant lesions or inflammatory lesions from two (18)F-FDG PET/CT images. Four different PET parameters were used to compare between the two studies: SUVmax, SUVmean, average activity over 30 % of the isocontour (isocontour, Bq/mL), and isocontour-mediastinal activity (Bq/mL). Additionally, we classified the patients into two groups: the responder or non-responder group according to the presence of PIO effect on skeletal muscle. Furthermore, PET parameters of malignant lesions were analyzed based on the type of malignancy and were compared with those of inflammatory lesions. RESULTS All four PET parameters of malignant lesions in the responder group showed increasing patterns after the use of PIO. In the subgroup analysis, the similar pattern was observed in gastrointestinal cancer. In hepatobiliary and pancreatic cancer, SUVmean and isocontour showed statistically significant increase in the presence of PIO. On the other hand, in the non-responder group, all four PET parameters showed decreasing patterns in both malignant and inflammatory lesions after the use of PIO. There was no statistically significant difference in PET parameters of malignant lesions in the non-responder group. CONCLUSIONS In this study, we found that PIO had the potential to increase (18)F-FDG uptake of malignant lesions in the patients who showed PIO effect on skeletal muscle. Contrary to our preclinical studies, clinical results had limitations to evaluate malignant lesions in non-responder group. Further larger-scale studies are necessary to elucidate the potential role of PIO on (18)F-FDG uptake in malignant or inflammatory lesions. TRIAL REGISTRATION The test for safety and effectiveness of the new efficacy of Pioglitazone to diagnose the malignant tumor and inflammation in F-18 FDG positron emission tomography (PET) study, 12029.
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Affiliation(s)
- Yeon-Hee Han
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
| | - Seong Young Kwon
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun-gun, Jeonnam, Republic of Korea.
| | - Jeonghun Kim
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
| | - Chang Ju Na
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
| | - Sehun Choi
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
| | - Jung-Joon Min
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun-gun, Jeonnam, Republic of Korea.
| | - Hee-Seung Bom
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun-gun, Jeonnam, Republic of Korea.
| | - Young-Chul Kim
- Lung and Esophageal Cancer Clinic, Chonnam National University Hwasun Hospital, Hwasun-gun, Jeonnam, Republic of Korea.
| | - In-Jae Oh
- Lung and Esophageal Cancer Clinic, Chonnam National University Hwasun Hospital, Hwasun-gun, Jeonnam, Republic of Korea.
| | - Han-Jung Chae
- Department of Pharmacology, Chonbuk National University Medical School, Jeonju, Jeonbuk, Republic of Korea.
| | - Seok Tae Lim
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
| | - Myung-Hee Sohn
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
| | - Hwan-Jeong Jeong
- Department of Nuclear Medicine, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju, Jeonbuk, Republic of Korea.
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11
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Rongen GA, Wever KE. Cardiovascular pharmacotherapy: Innovation stuck in translation. Eur J Pharmacol 2015; 759:200-4. [PMID: 25814253 DOI: 10.1016/j.ejphar.2015.03.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/07/2015] [Accepted: 03/12/2015] [Indexed: 12/25/2022]
Abstract
Systematic reviews of animal studies have revealed serious limitations in internal and external validity strongly affecting the reliability of this research. In addition inter-species differences are likely to further limit the predictive value of animal research for the efficacy and tolerability of new drugs in humans. Important changes in the research process are needed to allow efficient translation of preclinical discoveries to the clinic, including improvements in the laboratory and publication practices involving animal research and early incorporation of human proof-of-concept studies to optimize the interpretation of animal data for its predictive value for humans and the design of clinical trials.
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Affiliation(s)
- Gerard A Rongen
- Department of Pharmacology-Toxicology and Internal Medicine, Radboud university medical center, P.O. box 9101, Internal post address: 137, 6500 HB Nijmegen, The Netherlands.
| | - Kimberley E Wever
- SYstematic Review Centre for Laboratory animal Experimentation, Radboud university medical center, Nijmegen, The Netherlands
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12
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Baker DJ, Atkinson AM, Wilkinson GP, Coope GJ, Charles AD, Leighton B. Characterization of the heterozygous glucokinase knockout mouse as a translational disease model for glucose control in type 2 diabetes. Br J Pharmacol 2014; 171:1629-41. [PMID: 24772483 DOI: 10.1111/bph.12498] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE The global heterozygous glucokinase (GK) knockout (gk(wt/del)) male mouse, fed on a high-fat (60% by energy) diet, has provided a robust and reproducible model of hyperglycaemia. This model could be highly relevant to some facets of human type 2 diabetes (T2D). We aimed to investigate the ability of standard therapeutic agents to lower blood glucose at translational doses, and to explore the glucose-lowering potential of novel glucokinase activators (GKAs) in this model. EXPERIMENTAL APPROACH We measured the ability of insulin, metformin, glipizide, exendin-4 and sitagliptin, after acute or repeat dose administration, to lower free-feeding glucose levels in gk(wt/del) mice. Further, we measured the ability of novel GKAs, GKA23, GKA71 and AZD6370 to control glucose either alone or in combination with some standard agents. KEY RESULTS A single dose of insulin (1 unit·kg(-1)), metformin (150, 300 mg·kg(-1)), glipizide (0.1, 0.3 mg·kg(-1)), exendin-4 (2, 20 μg·kg(-1)) and GKAs reduced free-feeding glucose levels. Sitagliptin (10 mg·kg(-1)), metformin (300 mg·kg(-1)) and AZD6370 (30, 400 mg·kg(-1)) reduced glucose excursions on repeat dosing. At a supra-therapeutic dose (400 mg·kg(-1)), AZD6370 also lowered basal levels of glucose without inducing hypoglycaemia. CONCLUSION AND IMPLICATIONS Standard glucose-lowering therapeutic agents demonstrated significant acute glucose lowering in male gk(wt/del) mice at doses corresponding to therapeutic free drug levels in man, suggesting the potential of these mice as a translatable model of human T2D. Novel GKAs also lowered glucose in this mouse model.
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13
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Gowda N, Dandu A, Singh J, Biswas S, Raghav V, Lakshmi MN, Shilpa PC, Sunil V, Reddy A, Sadasivuni M, Aparna K, Verma MK, Moolemath Y, Anup MO, Venkataranganna MV, Somesh BP, Jagannath MR. Treatment with CNX-011-67, a novel GPR40 agonist, delays onset and progression of diabetes and improves beta cell preservation and function in male ZDF rats. BMC Pharmacol Toxicol 2013; 14:28. [PMID: 23692921 PMCID: PMC3668190 DOI: 10.1186/2050-6511-14-28] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Accepted: 05/15/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The role of G protein-coupled receptor (GPR40), which is highly expressed in pancreatic beta cells, has been studied extensively in the amelioration of beta cell dysfunction in T2D using rat and mouse islets, beta cell lines and in animal models of diabetes. But its potential as a therapeutic target has not been fully explored. This aim of the study is to evaluate the therapeutic potential of CNX-011-67, a highly selective, potent and orally bioavailable GPR40 agonist, in controlling diabetes and other metabolic parameters. METHODS Seven week old male ZDF rats were treated with either vehicle or CNX-011-67, 5 mg/kg twice daily, for seven weeks. The animals were subjected to oral glucose tolerance and insulin tolerance tests. Plasma glucose, insulin, triglyceride, HbA1c, fructosamine and free fatty acids were measured at selected time points. Pancreas from control and treated animals were subjected to insulin and pancreatic and duodenal homeobox 1 (PDX1) immunohistochemistry and were also evaluated by electron microscopy. Also the potential impact of CNX-011-67 on islet insulin secretion, content, ATP levels and markers of both glucose oxidation, beta cell health in rat islets under chronic glucolipotoxic conditions was evaluated. RESULTS Treatment of male ZDF rats with CNX-011-67 for 7 weeks significantly enhanced insulin secretion in response to oral glucose load, delayed the onset of fasting hyperglycemia by 3 weeks, reduced nonfasting glucose excursions, fasting free fatty acids and triglyceride levels. A significant increase in PDX1 expression and insulin content and reduction in plasma fructosamine, HOMA-IR, and beta cell apoptosis were observed. CNX-011-67 improves glucose mediated insulin secretion, insulin gene transcription and islet insulin content in cultured rat islets under chronic glucolipotoxic condition. Also enhanced glucose oxidation in the form of increased islet ATP content and overall improvement in beta cell health in the form of reduced expression of stress markers (TXNIP and CHOP mRNA) were observed. CONCLUSIONS These findings, suggest that long-term oral therapy with CNX-011-67 could be of clinical value to provide good glycemic control and improve islet beta cell function.
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14
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Bénardeau A, Verry P, Atzpodien EA, Funk JM, Meyer M, Mizrahi J, Winter M, Wright MB, Uhles S, Sebokova E. Effects of the dual PPAR-α/γ agonist aleglitazar on glycaemic control and organ protection in the Zucker diabetic fatty rat. Diabetes Obes Metab 2013; 15:164-74. [PMID: 22958363 DOI: 10.1111/dom.12006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/12/2012] [Accepted: 09/02/2012] [Indexed: 12/27/2022]
Abstract
AIMS To evaluate the effects of aleglitazar, a dual peroxisome proliferator-activated receptor-α/γ agonist, on the development of diabetes-related organ dysfunction, in relation to glycaemic and lipid changes, in Zucker diabetic fatty (ZDF) rats. METHODS Six-week-old, male ZDF rats received aleglitazar 0.3 mg/kg/day or vehicle as food admix for 13 weeks (n = 10 per group). Age-matched male Zucker lean rats served as non-diabetic controls. Plasma and renal markers were measured at several time points. Histopathology and quantitative immunohistochemistry were performed at 13 weeks. RESULTS Glycated haemoglobin (5.4 vs. 9.2%) and blood glucose (8.3 ± 0.3 vs. 26.1 ± 1.0 mmol/l) were significantly reduced at 12 weeks with aleglitazar versus vehicle-treated ZDF rats (both p < 0.01), while aleglitazar preserved near-normal plasma insulin levels. Aleglitazar prevented the development of hypertriglyceridaemia (1.4 ± 0.1 vs. 8.5 ± 0.9 mmol/l) and reduced plasma non-esterified fatty acids (0.09 ± 0.02 vs. 0.26 ± 0.04 mmol/l) relative to vehicle-treated animals (both p < 0.01). Urinary glucose and protein concentrations were significantly reduced at 13 weeks with aleglitazar versus vehicle-treated rats (both p < 0.01). Consistent with its effect on glycaemic control, aleglitazar protected β-cell morphology, as evidenced by preservation of islet integrity, and reduction of β-cell apoptosis and islet fibrosis. Aleglitazar prevented renal glomerular hypertrophy, podocyte degeneration, glomerulosclerosis, tubulo-interstitial lesions and development of cataracts. CONCLUSIONS Aleglitazar strongly improved glycaemic and lipid parameters while protecting key tissues, including the pancreas, kidneys and eyes, against diabetes-associated structural and functional changes in the ZDF rat.
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Affiliation(s)
- A Bénardeau
- pRED, Pharma Research & Early Development, DTA Cardiovascular & Metabolism, F. Hoffmann-La Roche AG, Basel, Switzerland
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15
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Bensellam M, Laybutt DR, Jonas JC. The molecular mechanisms of pancreatic β-cell glucotoxicity: recent findings and future research directions. Mol Cell Endocrinol 2012; 364:1-27. [PMID: 22885162 DOI: 10.1016/j.mce.2012.08.003] [Citation(s) in RCA: 198] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/11/2012] [Accepted: 08/01/2012] [Indexed: 02/06/2023]
Abstract
It is well established that regular physiological stimulation by glucose plays a crucial role in the maintenance of the β-cell differentiated phenotype. In contrast, prolonged or repeated exposure to elevated glucose concentrations both in vitro and in vivo exerts deleterious or toxic effects on the β-cell phenotype, a concept termed as glucotoxicity. Evidence indicates that the latter may greatly contribute to the pathogenesis of type 2 diabetes. Through the activation of several mechanisms and signaling pathways, high glucose levels exert deleterious effects on β-cell function and survival and thereby, lead to the worsening of the disease over time. While the role of high glucose-induced β-cell overstimulation, oxidative stress, excessive Unfolded Protein Response (UPR) activation, and loss of differentiation in the alteration of the β-cell phenotype is well ascertained, at least in vitro and in animal models of type 2 diabetes, the role of other mechanisms such as inflammation, O-GlcNacylation, PKC activation, and amyloidogenesis requires further confirmation. On the other hand, protein glycation is an emerging mechanism that may play an important role in the glucotoxic deterioration of the β-cell phenotype. Finally, our recent evidence suggests that hypoxia may also be a new mechanism of β-cell glucotoxicity. Deciphering these molecular mechanisms of β-cell glucotoxicity is a mandatory first step toward the development of therapeutic strategies to protect β-cells and improve the functional β-cell mass in type 2 diabetes.
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Affiliation(s)
- Mohammed Bensellam
- Université catholique de Louvain, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Brussels, Belgium
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16
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Jones HB, Bigley AL, Pemberton J, Randall KJ. Quantitative histopathological assessment of retardation of islets of langerhans degeneration in rosiglitazone-dosed obese ZDF rats using combined insulin and collagens (I and III) immunohistochemistry with automated image analysis and statistical modeling. Toxicol Pathol 2012; 41:425-44. [PMID: 23047688 DOI: 10.1177/0192623312460923] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Islets of Langerhans represent a heterogeneous population in insulin resistant and diabetic animals and humans as histological appearances and function vary substantially. Mathematical representation that reflects this morphological diversity will assist in assessment of degeneration and regeneration, enabling comparisons between species, strains, and experimental investigations. Our investigative approach used a model of islet degeneration in diabetic male obese Zucker Diabetic Fatty (ZDF) rats and evaluated its prevention using rosiglitazone treatment. Immunohistochemical staining (insulin and collagens I/III) with automated image analysis reliably measured numbers, area, clustering, and staining intensity of β-cells and degree of islet fibrosis. Finite mixture mathematical modeling for the joint probability distribution of seven islet parameters to represent islet numerical data variation provided an automatic procedure for islet category allocations as normal or abnormal. Allocations for obese ZDF controls and rosiglitazone-treated animals were significantly different, with no significant difference between the latter and lean ZDF controls, indicative of differences within islet populations of individual animals, between lean and obese rat strains and following drug treatment. Islet morphology showed clear association with mathematical characterization. Information on islet morphology obtained by histopathological assessment of single pancreatic tissue sections was confirmed by this method showing drug-induced retardation of islet of Langerhans degeneration.
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Affiliation(s)
- Huw B Jones
- Pathology Group, Global Safety Assessment, Alderley Park, Macclesfield, Cheshire, United Kingdom.
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17
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Welters HJ, El Ouaamari A, Kawamori D, Meyer J, Hu J, Smith DM, Kulkarni RN. Rosiglitazone promotes PPARγ-dependent and -independent alterations in gene expression in mouse islets. Endocrinology 2012; 153:4593-9. [PMID: 22807489 PMCID: PMC3512010 DOI: 10.1210/en.2012-1243] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The glitazone class of insulin-sensitizing agents act, in part, by the activation of peroxisome proliferator-activated receptor (PPAR)-γ in adipocytes. However, it is unclear whether the expression of PPARγ in the islets is essential for their potential β-cell-sparing properties. To investigate the in vivo effects of rosiglitazone on β-cell biology, we used an inducible, pancreatic and duodenal homeobox-1 enhancer element-driven, Cre recombinase to knockout PPARγ expression specifically in adult β-cells (PPARgKO). Subjecting the PPARgKO mice to a chow diet led to virtually undetectable changes in glucose or insulin sensitivity, which was paralleled by minimal changes in islet gene expression. Similarly, challenging the mutant mice with a high-fat diet and treatment with rosiglitazone did not alter insulin sensitivity, glucose-stimulated insulin secretion, islet size, or proliferation in the knockout mice despite PPARγ-dependent and -independent changes in islet gene expression. These data suggest that PPARγ expression in the β-cells is unlikely to be directly essential for normal β-cell function or the insulin-sensitizing actions of rosiglitazone.
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Affiliation(s)
- Hannah J Welters
- Peninsula College of Medicine and Dentistry, University of Exeter, Exeter EX2 5DW, United Kingdom.
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18
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Udayasankar J, Zraika S, Aston-Mourney K, Subramanian SL, Brooks-Worrell BM, Taborsky GJ, Hull RL. Rosiglitazone treatment does not decrease amyloid deposition in transplanted islets from transgenic mice expressing human islet amyloid polypeptide. Transplant Proc 2012; 45:574-9. [PMID: 23267797 DOI: 10.1016/j.transproceed.2012.05.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 05/04/2012] [Indexed: 12/17/2022]
Abstract
In human islet transplantation, insulin independence decreases over time. We previously showed that amyloid deposition following transplantation of islets from human islet amyloid polypeptide (hIAPP) transgenic mice resulted in ß-cell loss and that rosiglitazone treatment decreased islet amyloid deposition and preserved ß-cell area in the endogenous pancreas of hIAPP transgenic mice. Thus, we sought to determine if rosiglitazone treatment decreases islet amyloid deposition and the associated ß-cell loss after islet transplantation. Streptozocin-diabetic mice were transplanted with 100 islets from hIAPP transgenic (T) mice or nontransgenic (NT) littermates under the kidney capsule and received either rosiglitazone (R) in drinking water or plain drinking water (C). The resultant groups (NTC [n = 11], NTR [n = 9], TC [n = 14], and TR [n = 10]) were followed for 12 weeks after which the graft was removed and processed for histology. Amyloid was detected in nearly all T islet grafts (TC = 13/14, TR = 10/10) but not in NT grafts. Rosiglitazone did not alter amyloid deposition (% graft area occupied by amyloid; TC: 2.15 ± 0.7, TR: 1.72 ± 0.66; P = .86). % ß-cell/graft area was decreased in the TC grafts compared to NTC (56.2 ± 3.1 vs 73.8 ± 1.4; P < .0001) but was not different between TC and TR groups (56.2 ± 3.1 vs 61.0 ± 2.9; P = .34). Plasma glucose levels before and after transplantation did not differ between NTC and TC groups and rosiglitazone did not affect plasma glucose levels post-islet transplantation. Rosiglitazone did not decrease amyloid deposition in hIAPP transgenic islet grafts. Therefore, rosiglitazone treatment of recipients of amyloid forming islets may not improve transplantation outcomes.
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Affiliation(s)
- J Udayasankar
- Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System and University of Washington, Seattle, Washington 98108, USA
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Kelley R, Bruce A, Spencer T, Werdin E, Ilagan R, Choudhury S, Rivera E, Wallace S, Guthrie K, Jayo M, Xu F, Rao AN, Humphreys BD, Presnell S, Bertram T. A population of selected renal cells augments renal function and extends survival in the ZSF1 model of progressive diabetic nephropathy. Cell Transplant 2012; 22:1023-39. [PMID: 22889490 DOI: 10.3727/096368912x653237] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
New treatment paradigms that slow or reverse progression of chronic kidney disease (CKD) are needed to relieve significant patient and healthcare burdens. We have shown that a population of selected renal cells (SRCs) stabilized disease progression in a mass reduction model of CKD. Here, we further define the cellular composition of SRCs and apply this novel therapeutic approach to the ZSF1 rat, a model of severe progressive nephropathy secondary to diabetes, obesity, dyslipidemia, and hypertension. Injection of syngeneic SRCs into the ZSF1 renal cortex elicited a regenerative response that significantly improved survival and stabilized disease progression to renal structure and function beyond 1 year posttreatment. Functional improvements included normalization of multiple nephron structures and functions including glomerular filtration, tubular protein handling, electrolyte balance, and the ability to concentrate urine. Improvements to blood pressure, including reduced levels of circulating renin, were also observed. These functional improvements following SRC treatment were accompanied by significant reductions in glomerular sclerosis, tubular degeneration, and interstitial inflammation and fibrosis. Collectively, these data support the utility of a novel renal cell-based approach for slowing renal disease progression associated with diabetic nephropathy in the setting of metabolic syndrome, one of the most common causes of end-stage renal disease.
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Affiliation(s)
- Rusty Kelley
- Tengion, Inc., Science and Technology, Winston-Salem, NC 27103, USA.
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Gao W, Jusko WJ. Modeling disease progression and rosiglitazone intervention in type 2 diabetic Goto-Kakizaki rats. J Pharmacol Exp Ther 2012; 341:617-25. [PMID: 22378938 DOI: 10.1124/jpet.112.192419] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The pharmacokinetics (PK) and pharmacodynamics (PD) of rosiglitazone were studied in type 2 diabetic (T2D) Goto-Kakizaki (GK) rats that received daily doses of 0, 5, or 10 mg/kg for 23 days followed by 60 days of washout. Blood glucose, plasma insulin, and hemoglobin A1c were determined over time. Oral glucose tolerance tests were performed before and at the end of treatment and after 20 days of washout to determine insulin sensitivity and β-cell function. Rosiglitazone effectively lowered glucose by inhibiting hepatic glucose production and enhancing insulin sensitivity. The glucose-insulin inter-regulation was characterized by a feedback model: glucose and insulin have their own production (k(in)) and elimination (k(out)) rate constants, whereas glucose stimulates insulin production (k(inI)) and insulin, in turn, promotes glucose utilization (k(outG)). Animal handling and placebo treatment affected glucose turnover with k(pl) = 0.388 kg/mg/day. The PK of rosiglitazone was fitted with a one-compartment model with first-order absorption. The effect of rosiglitazone was described as inhibition of k(inG) with I(max) = 0.296 and IC(50) = 1.97 μg/ml. Rosiglitazone also stimulated glucose utilization by improving insulin sensitivity with a linear factor S(R) = 0.0796 kg/mg. In GK rats, 23 days of treatment increased body weight but did not cause hemodilution. Weight gain was characterized with body weight input (k(s)(w)) and output (k(d)(w)), and rosiglitazone inhibited k(d)(w) with ID(50) = 96.8 mg/kg. The mechanistic PK/PD model quantitatively described the glucose-insulin system and body weights under chronic rosiglitazone treatment in T2D rats.
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Affiliation(s)
- Wei Gao
- Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
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Hempe J, Elvert R, Schmidts HL, Kramer W, Herling AW. Appropriateness of the Zucker Diabetic Fatty rat as a model for diabetic microvascular late complications. Lab Anim 2012; 46:32-9. [DOI: 10.1258/la.2011.010165] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Male obese Zucker Diabetic Fatty (ZDF) rats develop type 2 diabetes around eight weeks of age, and are widely used as a model for human diabetes and its complications. The objective of the study was to test whether the complications manifested in the kidney and nerves of ZDF rats really correspond to human diabetic complications in their being related to the hyperglycaemic state. Four groups of ZDF rats were used. One lean (Fa/?) and one obese (fa/fa) untreated group served as non-diabetic and diabetic controls. In two further groups of obese (fa/fa) rats, diabetes was prevented by pioglitazone or delayed by food restriction. All rats were monitored up to 35 weeks of age with respect to their blood glucose, HbA1c and insulin levels, their kidney function (urinary glucose excretion, renal glucose filtration, glomerular filtration rate, albumin/creatinine ratio), and their nerve function (tactile and thermal sensory threshold and nerve conduction velocity). Pioglitazone prevented the development of diabetes, while food restriction delayed its onset for 8–10 weeks. Accordingly, kidney function parameters were similar to lean non-diabetic rats in pioglitazone-treated rats and significantly improved in food-restricted rats compared with obese controls. Kidney histology paralleled the functional results. By contrast, nerve functional evaluations did not mirror the differing blood glucose levels. We conclude that the ZDF rat is a good model for diabetic nephropathy, while alterations in nerve functions were not diabetes-related.
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Affiliation(s)
- J Hempe
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - R Elvert
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - H-L Schmidts
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - W Kramer
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - A W Herling
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
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Reversibility of hyperglycaemia and islet abnormalities in the high fat-fed female ZDF rat model of type 2 diabetes. J Pharmacol Toxicol Methods 2011; 63:15-23. [DOI: 10.1016/j.vascn.2010.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 03/23/2010] [Accepted: 04/01/2010] [Indexed: 01/09/2023]
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Atkinson LL, Topp BG, Au J, Vinerian HV, Dhatt N, Finegood DT. Quantification of the relationship between glycemia and beta-cell mass adaptation in vivo. Can J Physiol Pharmacol 2010; 87:602-9. [PMID: 19767884 DOI: 10.1139/y09-044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Beta-cell mass dynamics play an important role in the adaptation to obesity, as well as in the pathogenesis of type 2 diabetes. Here we used a 24-hour modified hyperglycemic clamp protocol to investigate the effect of increasing glucose concentrations (15, 20, 25, or 35 mmol/L) on beta-cell mass and rates of beta-cell replication, death, and neogenesis in 6-week-old Sprague Dawley rats (n = 40). During the first 4 h of glucose infusion, plasma insulin levels rose to an approximate steady state in each group, but by the end of 24 h, there was no difference in insulin levels between any of the groups. There was also no difference in beta-cell mass between groups. Mean beta-cell replication rates displayed a linear relationship to mean plasma glucose levels in all hyperglycemic animals (r(2) = 0.98, p < 0.05). Relative to the uninfused basal control animals, replication rates were significantly reduced in the 15 mmol/L glucose group. The percentage of TUNEL-positive beta-cells was not different between groups. There was also no significant difference in markers of neogenesis. Thus, these data demonstrate that hyperglycemia for 24 h had no effect on beta-cell mass, death, or neogenesis in 6-week-old Sprague Dawley rats. We demonstrate a linear relationship, however, between hyperglycemia and beta-cell replication rates in vivo.
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Affiliation(s)
- Laura L Atkinson
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada
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24
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Han JY, Kim YJ, Kim L, Choi SJ, Park IS, Kim JM, Chu YC, Cha DR. PPARgamma agonist and angiotensin II receptor antagonist ameliorate renal tubulointerstitial fibrosis. J Korean Med Sci 2010; 25:35-41. [PMID: 20052345 PMCID: PMC2799997 DOI: 10.3346/jkms.2010.25.1.35] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 03/06/2009] [Indexed: 11/20/2022] Open
Abstract
The peroxisome proliferator activated receptor (PPAR)gamma agonist is used as antidiabetic agent with antihyperglycemic and antihyperinsulinemic actions. Beyond these actions, antifibrotic effects have been reported. We examined antifibrotic effects of PPARgamma agonist and interaction with angiotensin receptor antagonist in the unilateral ureteral obstruction (UUO) model. After UUO, mice were divided to four groups: no treatment (CONT), pioglitazone treatment, L158809 treatment, and L158809+ pioglitazone treatment. On day 14, CONT mice showed severe fibrosis and all treated mice showed decreased fibrosis. The immunohistochmistry of PAI-1, F4/80 and p-Smad2 demonstrated that their expressions were increased in CONT group and decreased in the all treated groups compared to CONT. PAI-1 and p-Smad2 determined from Western blotting, among treated groups, was decreased compared to CONT group. The expression of TGF-beta1 from real time RT PCR showed markedly increased in the CONT group and decreased in all treated groups compared to CONT. These data suggest the pioglitazone inhibited tubulointerstitial fibrosis, however, the synergism between pioglitazone and L158809 is not clear. Considering decreased expression of PAI-1 and TGF-beta/Smad2 in the treated groups, PAI-1 and TGF-beta are likely linked to the decreased renal tubulointerstitial fibrosis. According to these results, the PPARgamma agonist might be used in the treatment of renal fibrotic disease.
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Affiliation(s)
- Jee-Young Han
- Department of Pathology, Inha University Hospital, Inha University Medical College, Incheon, Korea.
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25
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Capillary endothelial but not lymphatic function is restored under rosiglitazone in Zucker Diabetic Fatty rats. Microvasc Res 2009; 77:220-5. [DOI: 10.1016/j.mvr.2008.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 10/28/2008] [Accepted: 11/06/2008] [Indexed: 11/24/2022]
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26
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Atkinson LL, McDonald-Dyck C, Benkoczi C, Finegood DT. Effect of chronic rosiglitazone, metformin and glyburide treatment on beta-cell mass, function and insulin sensitivity in mZDF rats. Diabetes Obes Metab 2008; 10:780-90. [PMID: 17970758 DOI: 10.1111/j.1463-1326.2007.00811.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Here we investigate the effect of rosiglitazone (RSG), metformin (MET) and glyburide (GLIB) on plasma glucose levels, beta-cell mass, function and insulin sensitivity in 10-week-old diabetic male Zucker diabetic fatty (mZDF) rats using quantitative morphometry and a mathematical model beta-cell mass, insulin and glucose kinetics (betaIG). At treatment start, 10-week-old diabetic mZDF rats were severely hyperglycaemic and had very low beta-cell function (insulin secretory capacity). RSG treatment significantly lowered plasma glucose levels in 67% of the mZDF rats. MET was effective at lowering plasma glucose levels in 33% of the mZDF rats, while GLIB was completely ineffective at lowering blood glucose levels in 10-week-old mZDF rats. RSG treatment prevented the fall in beta-cell mass after 6-8 weeks of treatment accompanied by a significant decrease in beta-cell death while MET treatment had no effect on beta-cell mass. RSG treatment increased insulin sensitivity 10-fold, increased beta-cell function fivefold and modestly increased beta-cell mass 1.4-fold. MET treatment increased insulin sensitivity fourfold, with no significant effect on beta-cell function or mass. Although RSG treatment was highly successful in lowering plasma glucose levels, the 33% of mZDF rats that did not respond to the treatment had significantly lower beta-cell function prior to treatment start compared with the responder group. Thus, the low level of beta-cell function at treatment start may explain why none of these agents were completely effective at lowering blood glucose levels in 10-week-old diabetic mZDF rats. Nevertheless, these data suggest that the preservation of beta-cell mass and improvement in beta-cell function play a role in the overall beneficial effect of RSG in 10-week-old diabetic mZDF rats.
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Affiliation(s)
- L L Atkinson
- Diabetes Research Laboratory, School of Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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27
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Holloway AC, Petrik JJ, Bruin JE, Gerstein HC. Rosiglitazone prevents diabetes by increasing beta-cell mass in an animal model of type 2 diabetes characterized by reduced beta-cell mass at birth. Diabetes Obes Metab 2008; 10:763-71. [PMID: 17970760 DOI: 10.1111/j.1463-1326.2007.00808.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
AIM Interventions that preserve or increase beta-cell mass may also prevent type 2 diabetes. Rosiglitazone prevents diabetes in people with high glucose levels who have impaired glucose tolerance and/or impaired fasting glucose. The effect of this drug on both glucose levels and beta-cell mass was studied in a rat model of diabetes, characterized by reduced beta-cell mass at birth with normoglycaemia, and progression to dysglycaemia with age. METHODS Female Wistar rats were given either saline (vehicle) or nicotine during pregnancy and lactation. Offspring of saline-exposed dams were given vehicle and offspring of nicotine-exposed dams were randomized to receive either vehicle or rosiglitazone starting at weaning. Beta-cell mass, proliferation and apoptosis were determined at birth and at 4 and 26 weeks of age. Glucose homeostasis was examined following sequential oral glucose tolerance tests (OGTT). RESULTS Rosiglitazone treatment prevented the development of dysglycaemia in nicotine-exposed animals. The ability of rosiglitazone to preserve normoglycaemia appeared to be because of its ability to increase beta-cell mass through a combination of enhanced beta-cell proliferation and decreased beta-cell apoptosis. CONCLUSIONS These results suggest that if rosiglitazone administration is started prior to the onset of glucometabolic abnormalities, it prevents the onset of dysglycaemia by partially restoring beta-cell mass in animals with reduced beta-cell mass at birth.
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Affiliation(s)
- A C Holloway
- Reproductive Biology Division, Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada.
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28
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Decker M, Hofflich H, Elias AN. Thiazolidinediones and the preservation of beta-cell function, cellular proliferation and apoptosis. Diabetes Obes Metab 2008; 10:617-25. [PMID: 17645549 DOI: 10.1111/j.1463-1326.2007.00745.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The thiazolidinediones (TZDs) or glitazones are pharmaceutical agents that have profound effects on energy expenditure and conservation. They also exert significant anti-inflammatory effects and influence cell proliferation and cell death. The drugs are primarily used in clinical practice in the treatment of patients with type 2 diabetes mellitus, a disorder of insulin resistance that occurs when the pancreatic beta-cells are unable to produce adequate amounts of insulin to maintain euglycaemia. Loss of pancreatic beta-cell function in type 2 diabetes is progressive and often precedes overt diabetes by 10 years or more, as was shown by the United Kingdom Prospective Diabetes Study. Any therapeutic or preventive approach that would limit or reverse loss of beta-cell function in diabetes would have profound effects on the morbidity associated with this widespread disease. Evidence suggesting a potential role of TZDs in preserving beta-cell function in type 2 diabetes as well as the ability of these agents to exert anti-inflammatory and proapoptotic anticancer effects, and their ability to promote cellular proliferation in various organs is reviewed.
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Affiliation(s)
- Michael Decker
- Department of Medicine, University of California, Irvine Medical Center, Orange, CA 92868, USA
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29
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Matsui K, Ohta T, Oda T, Sasase T, Ueda N, Miyajima K, Masuyama T, Shinohara M, Matsushita M. Diabetes-associated complications in Spontaneously Diabetic Torii fatty rats. Exp Anim 2008; 57:111-21. [PMID: 18421173 DOI: 10.1538/expanim.57.111] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The Spontaneously Diabetic Torii (SDT) fatty rat, established by introducing the fa allele of the Zucker fatty rat into the SDT rat genome, is a new model of obese type 2 diabetes. The SDT-fa/fa (SDT fatty) rat shows overt obesity, and hyperglycemia and hyperlipidemia are observed at a young age as compared with the SDT-+/+ (SDT normal) rat. However, the features of the diabetic complications in the SDT fatty rat have not been reported. In the present study, the incidence and the progression of diabetic complications in the SDT fatty rat were examined, and compared with those of the SDT normal rat. Renal function parameters, such as blood urea nitrogen, urine volume and urinary protein, increased from 4 weeks of age in the SDT fatty rat, and pathological findings in the renal tubule were observed from 8 weeks. Furthermore, cataract was observed in the SDT fatty rat from 8 weeks of age, and prolongation of peak latencies on electroretinograms was observed at 16 and 24 weeks of age. On the other hand, in the SDT normal rat, renal or ocular changes were observed from 24 weeks of age. With early incidence of diabetes mellitus, diabetes-associated complications in the SDT fatty rat were seen at younger ages than those in the SDT normal rat. In conclusion, the SDT fatty rat is expected to be a useful model for the analysis of diabetic complications and the evaluation of drugs related to metabolic diseases.
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Affiliation(s)
- Kenichi Matsui
- Japan Tobacco Inc., Central Pharmaceutical Research Institute, Takatsuki, Osaka, Japan
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30
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Sarafidis PA. Thiazolidinedione derivatives in diabetes and cardiovascular disease: an update. Fundam Clin Pharmacol 2008; 22:247-64. [DOI: 10.1111/j.1472-8206.2008.00568.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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31
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Nugent DA, Smith DM, Jones HB. A review of islet of Langerhans degeneration in rodent models of type 2 diabetes. Toxicol Pathol 2008; 36:529-51. [PMID: 18467681 DOI: 10.1177/0192623308318209] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Type 2 diabetes mellitus (TTDM) is characterized by progressive loss of glucose control through multifactorial mechanisms. The search for an understanding of TTDM has relied on animal models since the realization of the importance of the pancreas in controlling plasma glucose concentration. Rodent models of TTDM are developed to express hyperglycemia and not islet degeneration per se. Degeneration of the islets of Langerhans with beta-cell loss is secondary to insulin resistance and is regarded as the more important lesion. Despite this, differences between models are seen in the development and progression of islet degeneration. Assessing the differences between the models is important to appreciate the various aspects of TTDM and understand their advantages as well as their deficiencies. Relevant animal models of TTDM provide opportunities to investigate important physiological and cell biological processes that may ultimately lead to development of targeted therapies. This article reviews the importance, advantages, and limitations of rodent models of TTDM in relation to the histopathological changes that characterize islet degeneration. Pathophysiological mechanisms that contribute to islet degeneration are also discussed and are placed into the context of changes in islet histological appearances.
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Affiliation(s)
- David A Nugent
- Pathology Department, Safety Assessment, AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield, Cheshire, United Kingdom
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32
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Szöcs Z, Brunmair B, Stadlbauer K, Nowotny P, Bauer L, Luger A, Fürnsinn C. Age-dependent development of metabolic derangement and effects of intervention with pioglitazone in Zucker diabetic fatty rats. J Pharmacol Exp Ther 2008; 326:323-9. [PMID: 18445783 DOI: 10.1124/jpet.108.136465] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Zucker diabetic fatty (ZDF) rats are a standard animal model for the study of type 2 diabetes and for pharmacological characterization of insulin-sensitizing drugs. To analyze the age-dependent development of their metabolic derangements and the associated changes in their responses to treatment with the insulin sensitizer pioglitazone, groups of 7, 10.5, or 15.5-week-old ZDF rats were treated orally with vehicle or pioglitazone (12 mg/kg/day). Metabolic parameters including circulating concentrations of glucose, insulin, lipids, and adiponectin as well as body weight, tissue glycogen content, and the activity of p70S6 kinase in skeletal muscle were determined. Blood glucose of ZDF rats rose steeply from 5.9 +/- 0.4 to 23.7 +/- 0.5 mM between 7 and 13 weeks of age and then reached a new steady state, which was associated with increased tissue glycogen content (in 15-week-old ZDF rats versus lean littermates: skeletal muscle, 18.0 +/- 0.9 versus 10.5 +/- 1.4 micromol/g; liver, 181 +/- 6 versus 109 +/- 14 micromol/g; both p < 0.001). Early intervention with pioglitazone at 7 weeks of age fully prevented the development of hyperglycemia (blood glucose, 6.4 +/- 0.4 versus 18.7 +/- 1.5 mM after 5.5 weeks of treatment), which was accompanied by a 40% (p = 0.01) reduction of the activity of p70S6 kinase in skeletal muscles. These beneficial effects of pioglitazone were progressively lost, if treatment was initiated at later stages of disease development. Thus, ZDF rats are suitable for preclinical characterization of insulin-sensitizing thiazolidinediones in many aspects, but several important differences versus human type 2 diabetes exist and are to be considered in the use of this animal model.
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Affiliation(s)
- Zsuzsanna Szöcs
- Department of Medicine III, Division of Endocrinology and Metabolism, Währinger Gürtel 18-20, A-1090 Vienna, Austria
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Larsen PJ, Wulff EM, Gotfredsen CF, Brand CL, Sturis J, Vrang N, Knudsen LB, Lykkegaard K. Combination of the insulin sensitizer, pioglitazone, and the long-acting GLP-1 human analog, liraglutide, exerts potent synergistic glucose-lowering efficacy in severely diabetic ZDF rats. Diabetes Obes Metab 2008; 10:301-11. [PMID: 18333889 DOI: 10.1111/j.1463-1326.2008.00865.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Severe insulin resistance and impaired pancreatic beta-cell function are pathophysiological contributors to type 2 diabetes, and ideally, antihyperglycaemic strategies should address both. RESEARCH DESIGN AND METHODS Therapeutic benefits of combining the long-acting human glucagon-like peptide-1 (GLP-1) analog, liraglutide (0.4 mg/kg/day), with insulin sensitizer, pioglitazone (10 mg/kg/day), were assessed in severely diabetic Zucker diabetic fatty rats for 42 days. Impact on glycaemic control was assessed by glycated haemoglobin (HbA(1C)) at day 28 and by oral glucose tolerance test at day 42. RESULTS Liraglutide and pioglitazone synergistically improved glycaemic control as reflected by a marked decrease in HbA(1C) (liraglutide + pioglitazone: 4.8 +/- 0.3%; liraglutide: 8.8 +/- 0.6%; pioglitazone: 7.9 +/- 0.4%; vehicle: 9.7 +/- 0.3%) and improved oral glucose tolerance at day 42 (area under the curve; liraglutide + pioglitazone: 4244 +/- 445 mmol/l x min; liraglutide: 7164 +/- 187 mmol/l x min; pioglitazone: 7430 +/- 446 mmol/l x min; vehicle: 8093 +/- 139 mmol/l x min). A 24-h plasma glucose profile at day 38 was significantly decreased only in the liraglutide + pioglitazone group. In addition, 24-h insulin profile was significantly elevated only in the liraglutide + pioglitazone group. Liraglutide significantly decreased food intake alone and in combination with pioglitazone, while pioglitazone alone increased cumulated food intake. As a result, rats on liraglutide alone gained significantly less weight than vehicle-treated rats, whereas rats on pioglitazone alone gained significantly more body weight than vehicle-treated rats. However, combination therapy with liraglutide and pioglitazone caused the largest weight gain, probably reflecting marked improvement of energy balance because of reduction of glucosuria. CONCLUSIONS Combination therapy with insulinotropic GLP-1 agonist liraglutide and insulin sensitizer, pioglitazone, improves glycaemic control above and beyond what would be expected from additive effects of the two antidiabetic agents.
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Oltman CL, Davidson EP, Coppey LJ, Kleinschmidt TL, Lund DD, Adebara ET, Yorek MA. Vascular and neural dysfunction in Zucker diabetic fatty rats: a difficult condition to reverse. Diabetes Obes Metab 2008; 10:64-74. [PMID: 17970755 DOI: 10.1111/j.1463-1326.2007.00814.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM We had previously demonstrated that vascular and neural dysfunction in Zucker diabetic fatty (ZDF) rats is progressive. In this study, we sought to determine whether monotherapy of ZDF rats can reverse the vascular and nerve defects. METHODS ZDF rats at 16 weeks of age were treated for 12 weeks with the angiotensin-converting enzyme inhibitor enalapril, the antioxidant alpha-lipoic acid, the HMG-CoA reductase inhibitor rosuvastatin or the PPARgamma agonist rosiglitazone. Vasodilation of epineurial arterioles was measured by videomicroscopy. Endoneurial blood flow (EBF) was measured by hydrogen clearance, and nerve conduction velocity was measured following electrical stimulation of motor or sensory nerves. RESULTS Motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNCV) (70 and 77% of control, respectively), EBF (64% of control), and vascular relaxation in response to acetylcholine (50% of control) and calcitonin gene-related peptide (CGRP; 73% of control) are impaired in ZDF rats at 28 weeks of age compared with lean littermate controls. Treatment with enalapril and alpha-lipoic acid attenuated the decrease in MNCV and SNCV. Enalapril, alpha-lipoic acid and rosiglitazone treatment of ZDF rats were partially effective in improving endothelium-dependent vascular dysfunction as measured by vascular relaxation in response to acetylcholine. The same drugs also attenuated the decrease in EBF. However, impairment in vascular relaxation in response to CGRP was improved with only alpha-lipoic acid or rosuvastatin treatment. The increase in superoxide and nitrotyrosine levels in vascular tissue was attenuated by all treatments. CONCLUSIONS The efficacy of monotherapy treatment of ZDF rats using different classes of drugs for vascular and neural dysfunction once complications have developed did not achieve expected levels. This could be because of the complex aetiology of vascular and neural disease in type 2 diabetes.
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Affiliation(s)
- C L Oltman
- Veteran Affairs Medical Center, University of Iowa, Iowa City, IA 52246, USA
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35
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Abstract
Type 2 diabetes is characterised by a gradual decline in glycaemic control and progression from oral glucose-lowering monotherapy to combination therapy and exogenous insulin therapy. Functional decline of the insulin-secreting beta-cells is largely responsible for the deterioration in glycaemic control. Preservation of beta-cell functionality, in addition to maintaining glycaemic control and reducing insulin resistance, is now regarded as a key target for long-term management strategies. Early, aggressive intervention with combination therapy is emerging as a valid approach to optimise long-term outcomes and combining agents with differing modes of action and secondary effect profiles should prove valuable. Sulfonylureas and thiazolidinediones exert their glucose-lowering effect through differing mechanisms of action - the sulfonylureas by stimulating insulin secretion, whereas the thiazolidinediones are insulin sensitisers. Both agents offer excellent improvements in glycaemic control when given as monotherapy or in combination. The thiazolidinediones protect beta-cell structural and functional integrity and functionality and complement the sulfonylureas by inducing and maintaining improvements in insulin resistance, the abnormal lipid profile associated with type 2 diabetes and other cardiovascular risk factors. Thus, there is a strong rationale to support the addition of thiazolidinediones to sulfonylureas as a treatment option for type 2 diabetes. This combination may be particularly effective in the early stages of the disease when beta-cell function is at its highest, allowing maximal benefit to be obtained from the insulin secretion-promoting abilities of the sulfonylureas and the beta-cell-protective effects of the thiazolidinediones.
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Affiliation(s)
- M Hanefeld
- Centre for Clinical Studies, GWT Technical University, Dresden, Germany.
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36
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Abstract
Despite intervention with effective oral glucose-lowering agents, most patients with type 2 diabetes will experience a gradual loss of glycaemic control. Irrespective of underlying levels of insulin resistance, the progressive failure and loss of beta-cells are ultimately responsible for the onset of frank type 2 diabetes. The mechanisms responsible for loss of beta-cell function are likely to be multifactorial, but may involve toxicity because of elevated glucose and/or lipid levels, increased secretory demand because of insulin resistance, amyloid deposition and altered levels of cytokines. Preservation of beta-cell function is now gaining recognition as a critical target in the management of type 2 diabetes. For patients with frank type 2 diabetes, preservation of beta-cell function has the potential to reduce or stabilise the progression of type 2 diabetes and to decrease the need for additional oral glucose-lowering agents and/or insulin therapy. There is a growing body of animal/preclinical evidence for improved and preserved beta-cell function with current glucose-lowering agents, such as the thiazolidinediones, metformin and the glucagon-like peptide-1 analogue, exenatide. Clinical studies incorporating indirect measures of beta-cell function also support a protective effect with some agents. A number of novel therapies that are currently under investigation may also offer beta-cell structural and functional protection, including dipeptidyl peptidase IV inhibitors and cannabinoid receptor type 1 blockers. Emerging evidence from interventional trials suggests that both intensive lifestyle changes and pharmacotherapy can delay or possibly prevent the onset of type 2 diabetes in high-risk individuals. For patients newly diagnosed with type 2 diabetes, early and aggressive intervention strategies that combine maximal glucose-lowering efficacy alongside potential beta-cell preserving properties may provide an opportunity to delay or prevent progression of the disease.
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Affiliation(s)
- E Standl
- Munich Institute of Diabetes Research and Medical Department, Krankenhaus Munchen-Schwabing, Munich, Germany.
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Ohtomo S, Izuhara Y, Takizawa S, Yamada N, Kakuta T, van Ypersele de Strihou C, Miyata T. Thiazolidinediones provide better renoprotection than insulin in an obese, hypertensive type II diabetic rat model. Kidney Int 2007; 72:1512-9. [PMID: 17898696 DOI: 10.1038/sj.ki.5002570] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Hyperinsulinemia has been implicated in the development of diabetic nephropathy. In the present study we compared the renoprotective effects of the thiazolidinedione, pioglitazone (PGZ), to that of insulin in a hypertensive, obese, type II diabetic rat model. PGZ aggravated obesity and gave less glycemic control than insulin. However, renoprotection was markedly better with PZG compared to insulin as shown by lower proteinuria, improved renal function, and less histological evidence of diabetic glomerular and tubulointerstitial lesions. PZG and insulin both reduced renal accumulation of pentosidine and oxidative stress to a similar extent. In contrast, PGZ but not insulin suppressed enhanced transforming growth factor-beta (TGF-beta) expression. We further confirmed in cultured rat proximal tubular cells that insulin enhanced TGF-beta mRNA expression and protein production. Our results identify hyperinsulinemia and the attendant increase of TGF-beta expression as potential therapeutic targets in diabetes independent of glycemic control. This confirms prior clinical evidence that PZG provides renoprotection in obese, diabetic patients with nephropathy.
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Affiliation(s)
- S Ohtomo
- Institute of Medical Sciences, Tokai University, Kanagawa, Japan
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38
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Abstract
Type 2 diabetes is a chronic disease characterized by progressive worsening of glycaemic control as indicated by the United Kingdom Prospective Diabetes Study (UKPDS). The progressive nature of the disease is mainly due to continuous loss of beta-cell mass and function. Though much of this loss is due to intrinsic defects of the beta-cell several factors may accelerate such process. These include the metabolic environment where hyperglycaemia and increased circulating free-fatty acid exert a toxic effect on the beta-cell. Therefore, tight metabolic control may prevent not only the risk of long-term diabetic complication but also preserve beta-cell function. Several therapeutic agents are currently used for treatment of type 2 diabetic patients. However, their effect on maintenance of beta-cell function has not been yet systematically reviewed. By literature searching we have then analysed in detail the effect of sulfonylureas and non-sulfonylureic secretagogues, incretin-mimetics, insulin sensitizers, alpha-glucosidase inhibitors, and insulin on beta-cell function. Moreover, promising future approaches aiming at preserving beta-cell function and mass are discussed.
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Affiliation(s)
- Stefano Del Prato
- Department of Endocrinology and Metabolism, Section of Diabetes and Metabolic Diseases, University of Pisa, Pisa, Italy.
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39
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Stepp DW. Impact of obesity and insulin resistance on vasomotor tone: nitric oxide and beyond. Clin Exp Pharmacol Physiol 2007; 33:407-14. [PMID: 16700872 DOI: 10.1111/j.1440-1681.2006.04381.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
1. Obesity is rapidly increasing in Western populations, driving a parallel increase in hypertension, diabetes and vascular disease. Prior to the development of overt diabetes or hypertension, obese patients spend years in a state of progressive insulin resistance and metabolic disease. Mounting evidence suggests that this insulin-resistant state has deleterious effects on the control of blood flow, thus placing organ systems at a higher risk for end-organ damage and increasing cardiovascular mortality. 2. The purpose of the present review is to examine the current literature on the effects of obesity and insulin resistance on the acute control of vascular tone. Effects on nitric oxide (NO)-mediated control of vascular tone are particularly examined with regard to proximal causes and distal mechanisms of the impaired NO-mediation of vasodilation. 3. Finally, novel pathways of impaired control of perfusion are summarized from the recent literature to identify new avenues of exploring impaired vascular function in patients with metabolic disease.
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Affiliation(s)
- David W Stepp
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia 30912-2500, USA.
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Choi SH, Zhao ZS, Lee YJ, Kim SK, Kim DJ, Ahn CW, Lim SK, Lee HC, Cha BS. The different mechanisms of insulin sensitizers to prevent type 2 diabetes in OLETF rats. Diabetes Metab Res Rev 2007; 23:411-8. [PMID: 17538941 DOI: 10.1002/dmrr.756] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To investigate the effects of pioglitazone and metformin treatment during pre-diabetic period for the prevention of diabetes in a rat model. METHODS OLETF rats aged 18-weeks, were treated with pioglitazone (10 mg/kg/day) and metformin (300 mg/kg/day) for 10 weeks from their pre-diabetic period. We measured weight, lipid profiles, fat distribution, glucose tolerance, and pancreatic insulin content. RESULTS Prominent weight gain (mostly subcutaneous fat area) was observed in the pioglitazone-treated OLETF (O-P) rats versus significant weight loss was observed in the metformin-treated OLETF (O-M) rats. Pioglitazone reversed the serum triglyceride (TG) and FFAs levels to normal (TG 0.46 +/- 0.04 vs 0.88 +/- 0.05 mmol/l in LETO). At the age of 28 weeks, the O-P rats showed completely normal glucose tolerance, and the glucose disposal rate (GDR) was markedly improved (25.6 +/- 0.4 vs 20.6 +/- 0.5 mg/min/kg in O-C, p < 0.05). The O-M rats also showed an improved fasting glucose and GDR level, but not as much as those with O-P rats. The pancreas insulin contents were much improved in the O-P rats (22.9 +/- 1.2 vs 18.8 +/- 1.3 nmol/pancreas in O-M rats, p < 0.05) with histological improvement. CONCLUSION The pre-diabetic treatment with pioglitazone, despite significant weight gain, completely prevents to develop diabetes and enhances beta cell function with preservation of islet cell changes. Metformin treatment was also effective, but mainly by ameliorating the insulin resistance with marked reduction in body weight. The reversal of dyslipidaemia and the fat redistribution might contribute to the greater improvement of pioglitazone treatment compared to metformin in OLETF rats.
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Affiliation(s)
- Sung Hee Choi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University College of Medicine, Bundang Hospital, Seongnam, Korea
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Campbell IW, Mariz S. Beta-cell preservation with thiazolidinediones. Diabetes Res Clin Pract 2007; 76:163-76. [PMID: 17052795 DOI: 10.1016/j.diabres.2006.08.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Revised: 08/25/2006] [Accepted: 08/29/2006] [Indexed: 12/14/2022]
Abstract
Progressive beta-cell dysfunction and beta-cell failure are fundamental pathogenic features of type 2 diabetes. Ultimately, the development and continued progression of diabetes is a consequence of the failure of the beta-cell to overcome insulin resistance. Strategies that aim to prevent diabetes must, therefore, ultimately aim to stabilize the progressive decline of the beta-cell. Clinical study evidence from several sources now suggests that thiazolidinediones (TZDs) have profound effects on the beta-cell, such as improving insulin secretory capacity, preserving beta-cell mass and islet structure and protecting beta-cells from oxidative stress, as well as improving measures of beta-cell function, such as insulinogenic index and homeostasis model assessment of beta-cell function (HOMA-%B). Furthermore, intervention studies suggest that TZDs have the potential to delay, stabilize and possibly even prevent the onset on diabetes in high-risk individuals, and these effects appear to accompany improvements in beta-cell function. Here, we review the evidence, from in vitro studies to large intervention trials, for the effects of TZDs on beta-cell function and the consequences for glucose-lowering therapy.
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Davis J, Higginbotham A, O'Connor T, Moustaid-Moussa N, Tebbe A, Kim YC, Cho KW, Shay N, Adler S, Peterson R, Banz W. Soy protein and isoflavones influence adiposity and development of metabolic syndrome in the obese male ZDF rat. ANNALS OF NUTRITION AND METABOLISM 2007; 51:42-52. [PMID: 17356265 DOI: 10.1159/000100820] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 06/01/2006] [Indexed: 12/18/2022]
Abstract
BACKGROUND/AIMS Previously, we demonstrated that soy protein ameliorates the diabetic phenotype in several rodent models of obesity and metabolic syndrome (MS). This study was designed to further elucidate factors related to adiposity, glycemic control, and renal function in male Zucker Diabetic Fatty (ZDF/Lepr(fa)) rats. METHODS Animals were randomly assigned to one of four diets: control, casein (C); low isoflavone (LIS) soy protein; high isoflavone (HIS) soy protein, or casein + rosiglitazone (CR) for 11 weeks. At sacrifice, physiological, biochemical, and molecular parameters were determined. RESULTS Body weight and total adiposity were higher in LIS and CR diet groups despite lower food intake. Additionally, these animals exhibited differential regulation of adipose-specific proteins (PPAR-gamma and GLUT4) and enzyme activity (FAS and GPDH). HIS-fed animals had reduced total and liver adiposity. Glycemic control was prolonged in both soy-based and rosiglitazone (RGZ) groups. Renal dysfunction was significantly reduced in soy-fed and RGZ-treated rodents as demonstrated by lower levels of proteinuria and dilated tubules with proteinaceous casts. CONCLUSION Collectively, these data provide evidence that soy protein with low or high isoflavone content may have therapeutic significance in reducing severity of diabetes, MS, and renal disease as demonstrated in this preclinical model.
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Affiliation(s)
- Jeremy Davis
- Southern Illinois University, Carbondale, IL 62901-4317, USA
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43
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Elte JWF, Blicklé JF. Thiazolidinediones for the treatment of type 2 diabetes. Eur J Intern Med 2007; 18:18-25. [PMID: 17223037 DOI: 10.1016/j.ejim.2006.09.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Revised: 09/01/2006] [Accepted: 09/19/2006] [Indexed: 11/22/2022]
Abstract
Thiazolidinediones (TZD), or glitazones, represent a new generation of antidiabetic drugs that have recently been introduced in Europe. They improve insulin resistance, one of the key anomalies involved in the pathogenesis of type 2 diabetes mellitus, by activating the nuclear peroxoxisome proliferator activated receptor-gamma (PPAR-gamma), leading to crucial metabolic alterations in adipose tissue. Rosiglitazone and pioglitazone have been shown to be active as monotherapy, in combination therapy with metformin or sulfonylureas, and even in triple therapy. They are generally well tolerated but can induce fluid retention. Cardiac failure is a contraindication for the use of TZDs, as is the concomitant administration of insulin. Aside from their effect on glycemic control, TZDs act on several cardiovascular risk factors and may protect pancreatic beta cells from apoptosis. The cardiovascular protective effect of TZDs has recently been demonstrated with the results of the PROactive study, and long-term preservation of beta-cell function is currently under further investigation.
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Affiliation(s)
- J W F Elte
- Sint Franciscus Gasthuis, Department of Internal Medicine, Kleiweg 500, 3045 PM Rotterdam, The Netherlands
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Hanefeld M, Patwardhan R, Jones NP. A one-year study comparing the efficacy and safety of rosiglitazone and glibenclamide in the treatment of type 2 diabetes. Nutr Metab Cardiovasc Dis 2007; 17:13-23. [PMID: 17174222 DOI: 10.1016/j.numecd.2005.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2005] [Revised: 11/08/2005] [Accepted: 12/01/2005] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND AIM This study was designed to compare the efficacy of rosiglitazone and glibenclamide in individuals with type 2 diabetes over a 12-month period. METHODS AND RESULTS A total of 598 patients were randomized to double-blind treatment for 52 weeks with rosiglitazone 4 mg/d (n=200), rosiglitazone 8 mg/d (n=191) or glibenclamide (n=207; dose adjusted up to 15 mg/d over the first 12 weeks according to clinical response). Changes in fasting plasma glucose (FPG), haemoglobin A1c (HbA1c), fasting insulin and its precursor peptides, and lipids were measured and safety was evaluated. Significant reductions in HbA1c levels at 52 weeks compared with baseline were seen in all treatment groups (rosiglitazone 4 mg/d=-0.3%, P=0.0003; rosiglitazone 8 mg/d=-0.5%, P<0.0001; glibenclamide=-0.7%, P<0.0001). Mean FPG levels were also significantly reduced in all treatment groups (rosiglitazone 4 mg/d=-1.4 mmol/l; rosiglitazone 8 mg/d=-2.3 mmol/l; glibenclamide=-1.7 mmol/l; P<0.0001 vs. baseline for all treatments). Rosiglitazone therapy reduced plasma insulin, proinsulin, split proinsulin and free fatty acid levels compared with glibenclamide. Rosiglitazone improved insulin resistance while a worsening was seen with glibenclamide. Total:high-density lipoprotein cholesterol ratios were reduced with glibenclamide and unchanged with rosiglitazone. All treatments were generally well tolerated. CONCLUSIONS The efficacy of rosiglitazone 8 mg/d in improving glycaemic control in patients with type 2 diabetes is comparable to that of glibenclamide. However, rosiglitazone reduced insulin resistance and proinsulin levels whereas glibenclamide use was associated with an increase in fasting insulin and proinsulin. This suggests that in the long term, rosiglitazone may protect the beta-cell whereas glibenclamide is likely to increase the burden.
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Affiliation(s)
- Markolf Hanefeld
- Centre for Clinical Studies, GWT Technical University, Dresden, Germany.
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Noto A, Zahradka P, Ryz NR, Yurkova N, Xie X, Taylor CG. Dietary conjugated linoleic acid preserves pancreatic function and reduces inflammatory markers in obese, insulin-resistant rats. Metabolism 2007; 56:142-51. [PMID: 17161237 DOI: 10.1016/j.metabol.2006.09.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 09/27/2006] [Indexed: 01/04/2023]
Abstract
Pancreatic preservation is an important part of diabetes management that may occur with improved peripheral insulin sensitivity and attenuated low-grade adipose tissue inflammation. The objective of the current study was to determine the response of obese, insulin-resistant fa/fa Zucker rats vs lean controls to dietary conjugated linoleic acid (CLA) supplementation with respect to pancreatic islet size, insulin resistance, and markers of inflammation and adipose glucose uptake. Six-week-old fa/fa and lean Zucker rats (n = 20 per genotype) were fed either a 1.5% CLA mixture or control diet for 8 weeks. Oral glucose tolerance testing was conducted at 7.5 weeks. Fasting serum haptoglobin, insulin, and C-peptide were assayed, and select messenger RNA (mRNA) and protein markers of inflammation and glucose metabolism were measured in adipose and liver tissues. CLA-fed fa/fa Zucker rats had smaller islet cell size, improved oral glucose tolerance and insulinemia, and attenuated serum haptoglobin levels compared with control-fed fa/fa Zucker rats, despite no differences in body weight and a slightly higher visceral adipose mass. CLA did not alter insulin sensitivity or islet size in lean Zucker rats. The CLA-fed fa/fa rats also had greater adipose glucose transporter-4 mRNA and less adipose tumor necrosis factor alpha mRNA and protein compared with control-fed fa/fa rats. In contrast, other markers of inflammation and glucose metabolism including adipose macrophage inflammatory factor, macrophage inflammatory protein-2, and liver pyruvate carboxylase and pyruvate dehydrogenase kinase 4 were not significantly changed. These results suggest that CLA supplementation preserved pancreatic function in conjunction with improved peripheral glucose use and reduced inflammation in fa/fa Zucker rats.
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Affiliation(s)
- Amy Noto
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
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Nakano R, Kurosaki E, Shimaya A, Kajikawa S, Shibasaki M. YM440, a novel hypoglycemic agent, protects against nephropathy in Zucker fatty rats via plasma triglyceride reduction. Eur J Pharmacol 2006; 549:185-91. [PMID: 16989806 DOI: 10.1016/j.ejphar.2006.08.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 08/07/2006] [Accepted: 08/14/2006] [Indexed: 11/28/2022]
Abstract
The novel hypoglycemic agent, YM440 ((Z)-1,4-bis{4-[(3,5-dioxo-1,2,4-oxadiazolidin-2-yl) methyl] phenoxy}but-2-ene) is a ligand of the peroxisome proliferator-activated receptor, (PPAR) gamma. YM440 has been shown to counteract insulin resistance in diabetic rodent models. However, it is not clear whether this compound has a significant effect on hyperlipidemia in vivo. Hyperlipidemia has been reported to be a risk factor for the early development of renal disease. The aim of this study is to examine the effects of chronic treatment with YM440 on hyperlipidemia and renal injury in obese Zucker fatty (ZF) rats. Treatment of 8-week-old ZF rats with YM440 (100 mg/kg/day) for 16 weeks decreased plasma triglyceride and cholesterol concentrations. YM440 markedly reduced the rate of progression of both albuminuria and proteinuria. YM440 normalized urinary N-acetyl-beta-D-glucosaminidase (NAG) activity, which is a marker for renal proximal tubular damage, and ameliorated the rise in systolic blood pressure compared to the vehicle control. YM440 also blocked the development of nephromegaly. Histological analyses revealed that both glomerular area expansion and tubular cast accumulation gradually lessened in YM440-treated ZF rats. Regression analyses between the plasma triglyceride levels and the renal parameters (urinary protein excretion and albumin excretion) indicated that the renal parameters correlated positively with the plasma triglyceride levels. In conclusion, the hypolipidemic effects of YM440 prevent renal injury in ZF rats. YM440 might be useful for preventing the early development of diabetic nephropathy in subjects with type 2 diabetes by ameliorating metabolic control problems.
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Affiliation(s)
- Ryosuke Nakano
- Pharmacology Research Laboratories, Drug Discovery Research, Astellas Pharma Inc., Japan.
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Riazi S, Khan O, Tiwari S, Hu X, Ecelbarger CA. Rosiglitazone regulates ENaC and Na-K-2Cl cotransporter (NKCC2) abundance in the obese Zucker rat. Am J Nephrol 2006; 26:245-57. [PMID: 16757903 DOI: 10.1159/000093783] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Accepted: 04/26/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Progressive diabetes is associated renal remodeling, which we previously showed correlated to reduced protein abundance of several major renal sodium transporters and channel subunits in the obese Zucker rat. Here we test whether rosiglitazone (RGZ), a peroxisome proliferator-activated subtype gamma receptor agonist, would be protective and attenuate these changes. METHODS Male, obese and lean Zucker rats (9 weeks old) were randomly divided (n = 6/group) to receive control diet with or without RGZ at 3 mg/kg.bw/day for 12 weeks. RESULTS RGZ normalized blood glucose and plasma fructosamine levels in obese rats. Obese control rats had relatively increased fractional excretion of sodium (FE(Na), sodium excretion relative to creatinine). Nonetheless, both obese and RGZ-treated rats had relatively higher 24-hour net sodium balances. Immunoblotting revealed obese rats had significantly reduced renal cortical protein abundances of the bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) and the sodium hydrogen exchanger (NHE3). RGZ normalized NKCC2 abundance and increased the abundance of the alpha-subunit of the epithelial sodium channel (ENaC). In contrast, in the outer medulla, obese rats had increased abundance of NKCC2, gamma-ENaC (85-kDa), and endothelial NOS. Furthermore, RGZ caused a decrease in the abundance of cortical beta- and gamma-ENaC (85-kDa). Finally, the whole kidney abundances of alpha-1 Na-K-ATPase, alpha- beta-, and gamma-ENaC (70-kDa band) positively correlated with net sodium balance, whereas NKCC2 was negatively correlated to FE(Na). CONCLUSION Chronic RGZ treatment of obese Zucker rats may preserve renal sodium reabsorptive capacity by its indirect actions to attenuate hyperglycemia as well as direct effects on transporter abundance and activity.
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Affiliation(s)
- Shahla Riazi
- Department of Medicine, Division of Endocrinology and Metabolism, Georgetown University, Washington, DC 20057-1412, USA
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Dobrian AD. The complex role of PPARgamma in renal dysfunction in obesity: managing a Janus-faced receptor. Vascul Pharmacol 2006; 45:36-45. [PMID: 16716756 DOI: 10.1016/j.vph.2006.01.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2006] [Revised: 01/01/2006] [Accepted: 01/01/2006] [Indexed: 01/11/2023]
Abstract
Obesity is frequently accompanied by insulin resistance, type II diabetes, hypertension and atherosclerosis, a cluster of pathologies that are the major components of the metabolic syndrome. Obesity is a known cause for renal dysfunction that leads to two major renal pathologies: hypertension and glomerular and tubulointerstitial injury. Peroxizome proliferator activated receptors (PPARs) are transcription factors belonging to the nuclear hormone receptor superfamily with important functions in the regulation of metabolism. The role of PPARgamma isoforms in adipogenesis and vascular inflammation associated to obesity has been vastly studied and is well recognized, albeit not completely mechanistically understood. Also, the effect of various PPARgamma agonists on blood pressure reduction in different forms of hypertension, including obesity related hypertension has been reported, but the mechanisms involved are only beginning to be studied. Even less clear is the concurrent beneficial effect of PPARgamma agonists thiazolinendiones (TZD) on blood pressure reduction in different forms of hypertension and, at the same time, in some cases, the significant water retention leading to edema and heart failure. The occurrence of both these apparently opposite effects on the renal water and sodium handling suggests a complex role of PPARgamma in the kidney that is likely related to the metabolic state. Also, PPARgamma activation leads to a reduction in mesangial cell proliferation while stimulating apoptosis. TZD treatment reduces albuminuria in obese and diabetic humans and rodent models suggesting protective effects against renal tubuloglomerular injury. The focus of this review is to present and critically discuss the recent findings on the roles of PPARgamma in the kidney in direct relation to renal function and renal injury in obesity and obesity-initiated diabetes.
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Affiliation(s)
- Anca Dana Dobrian
- Department of Physiological Sciences, Eastern Virginia Medical School, 700W Olney Road, Lewis Hall, Room 2027, Norfolk, VA 23507, USA.
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He G, Sung YM, Digiovanni J, Fischer SM. Thiazolidinediones inhibit insulin-like growth factor-i-induced activation of p70S6 kinase and suppress insulin-like growth factor-I tumor-promoting activity. Cancer Res 2006; 66:1873-8. [PMID: 16452250 DOI: 10.1158/0008-5472.can-05-3111] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thiazolidinediones are a novel class of antidiabetic drugs that improve insulin sensitivity in type 2 diabetic patients. Recently, these compounds have also been shown to suppress tumor development in several animal models. The molecular basis for their antitumor action, however, is largely unknown. We report here that oral administration of thiazolidinediones (rosiglitazone and troglitazone) remarkably inhibited insulin-like growth factor-I (IGF-I)-promoted skin tumor development by 73% in BK5.IGF-1 transgenic mice, although they were previously found to be ineffective in inhibiting UV- or chemically induced mouse skin tumorigenesis. The anti-IGF-I effect of troglitazone in mouse skin keratinocytes was due to, at least partially, inhibition of IGF-I-induced phosphorylation of p70S6 kinase (p70S6K) at Thr(389), a site specifically phosphorylated by mammalian target of rapamycin (mTOR). Troglitazone did not directly inhibit mTOR kinase activity as shown by mTOR in vitro kinase assay but rapidly activated AMP-activated protein kinase (AMPK) through a yet undefined peroxisome proliferator-activated receptor gamma-independent mechanism. Expression of a dominant-negative AMPK reversed the inhibitory effect of troglitazone on IGF-I-induced phosphorylation of p70S6K, suggesting that troglitazone inhibited IGF-I and p70S6K signaling through activation of AMPK. Collectively, these data suggest that thiazolidinediones specifically inhibit IGF-I tumor-promoting activity in mouse skin through activation of AMPK and subsequent inhibition of p70S6K.
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Affiliation(s)
- Guobin He
- Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Science Park-Research Division, 1808 Park Road 1C, Smithville, TX 78957, USA
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Hefetz S, Ziv E, Jörns A, Lenzen S, Shafrir E. Prevention of nutritionally induced diabetes by rosiglitazone in the gerbil Psammomys obesus. Diabetes Metab Res Rev 2006; 22:139-45. [PMID: 16088969 DOI: 10.1002/dmrr.583] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND Psammomys obesus is a desert gerbil developing hyperglycaemia, hyperinsulinaemia and insulin resistance when placed for 2 weeks on a high-energy (HE) diet. The mechanism underlying the antidiabetic effect of rosiglitazone (RG) treatment (20 mg/kg per day for 2 weeks) was studied. METHODS The antidiabetogenic effect of RG treatment on serum insulin and metabolic parameters in serum and target tissues of insulin action was investigated in vivo and compared with the pancreatic beta cell protective effects of RG. RESULTS Almost all RG-treated animals remained normoglycaemic compared to controls, but, at the same time, they were hyperinsulinaemic. RG had no effect on serum free fatty acid and serum and muscle triglyceride concentrations and did not appreciably affect body weight and fat depots. RG prevented a HE diet-induced reduction of GLUT 4 glucose transporter content in epididymal adipose tissue, but not in gastrocnemius muscle. The normoglycaemic effect was not associated with a suppression of liver PEPCK activity. Muscle PKCepsilon expression, known to be elevated in diabetic Psammomys and to inhibit insulin signalling, was only marginally decreased. However, RG treatment prevented the marked decrease in insulin immunostaining as well as the vacuolization of the beta cells and accelerated beta cell proliferation. CONCLUSIONS These data indicate that the skeletal muscle is not the primary target of RG action, whereas the preservation of the insulin secretory capacity and the prevention of degenerative beta cell vacuolization in spite of persisting insulin resistance appear to be the basis for the anti-hyperglycaemic effect of RG in Psammomys.
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Affiliation(s)
- Simona Hefetz
- Diabetes Center, Hadassah University Hospital, Jerusalem, Israel
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