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Lin X, Parker L, McLennan E, Hayes A, McConell G, Brennan-Speranza TC, Levinger I. Undercarboxylated Osteocalcin Improves Insulin-Stimulated Glucose Uptake in Muscles of Corticosterone-Treated Mice. J Bone Miner Res 2019; 34:1517-1530. [PMID: 30908701 DOI: 10.1002/jbmr.3731] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 03/18/2019] [Accepted: 03/20/2019] [Indexed: 01/05/2023]
Abstract
Short-term administration of glucocorticoids (GCs) impairs muscle insulin sensitivity at least in part via the reduction of undercarboxylated osteocalcin (ucOC). However, whether ucOC treatment reverses the GC-induced muscle insulin resistance remains unclear. To test the hypothesis that ucOC directly ameliorates impaired insulin-stimulated glucose uptake (ISGU) induced by short-term GC administration in mice muscle and to identify the molecular mechanisms, mice were implanted with placebo or corticosterone (CS) slow-release pellets. Two days post-surgery, insulin-tolerance tests (ITTs) were performed. On day 3, serum was collected and extensor digitorum longus (EDL) and soleus muscles were isolated and treated ex vivo with vehicle, ucOC (30 ng/mL), insulin (60 µU/mL), or both. Circulating hormone levels, muscle glucose uptake, and muscle signaling proteins were assessed. CS administration reduced both serum osteocalcin and ucOC levels, whole-body insulin sensitivity, and muscle ISGU in EDL. Ex vivo ucOC treatment restored ISGU in CS-affected muscle, without increasing non-insulin-stimulated glucose uptake. In CS-affected EDL muscle, ucOC enhanced insulin action on phosphorylated (p-)protein kinase B (Akt)Ser473 and the p-extracellular signal-regulated kinase isoform 2 (ERK2)Thr202/Tyr204 /total (t)ERK2 ratio, which correlated with ISGU. In CS-affected soleus muscle, ucOC enhanced insulin action on p-mammalian target of rapamycin (mTOR)Ser2481 , the p-mTORSer2481 /tmTOR ratio, p-Akt substrate of 160kD (AS160)Thr642 , and p-protein kinase C (PKC) (pan)Thr410 , which correlated with ISGU. Furthermore, p-PKC (pan)Thr410 correlated with p-AktSer473 and p-AS160Thr642 . ucOC exerts direct insulin-sensitizing effects on CS-affected mouse muscle, likely through an enhancement in activity of key proteins involved in both insulin and ucOC signaling pathways. Furthermore, these effects are muscle type-dependent. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Xuzhu Lin
- Institute of Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - Lewan Parker
- Institute of Health and Sport (IHES), Victoria University, Melbourne, Australia.,Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia
| | - Emma McLennan
- Institute of Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - Alan Hayes
- Institute of Health and Sport (IHES), Victoria University, Melbourne, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia.,Department of Medicine-Western Health, Australian Institute for Musculoskeletal Science (AIMSS), Melbourne Medical School, The University of Melbourne, Melbourne, VIC, Australia
| | - Glenn McConell
- Institute of Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - Tara C Brennan-Speranza
- Department of Physiology and Bosch Institute for Medical Research, University of Sydney, Australia
| | - Itamar Levinger
- Institute of Health and Sport (IHES), Victoria University, Melbourne, Australia.,Department of Medicine-Western Health, Australian Institute for Musculoskeletal Science (AIMSS), Melbourne Medical School, The University of Melbourne, Melbourne, VIC, Australia
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Hsu JJ, Wang JI, Lee A, Li DY, Chen CH, Huang S, Liu A, Yoon BK, Kim SK, Tsai TJ. Automated control of blood glucose in the OR and surgical ICU. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2009:1286-9. [PMID: 19964000 DOI: 10.1109/iembs.2009.5333239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A device which integrates existing intravenous continuous glucose monitors and infusion pumps into a central hub for automated intravenous intensive insulin therapy, targeting non-diabetic critically-ill patients is presented. Additionally, a fuzzy logic based controller that is capable of automatically making closed-loop decisions to achieve tight glycemic control between a euglycemic range of 90 to 120 mg/dl is presented. Initial bench top testing shows a significant improvement in glycemic control with fuzzy logic control when compared to manual infusion protocols currently used in hospitals; future animal testing will be performed to verify these results in vivo.
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Affiliation(s)
- Jason J Hsu
- Johns Hopkins University Department of Biomedical Engineering and The Johns Hopkins Bayview Medical Center Department of Surgery, Baltimore, MD 21218, USA.
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