A Study of Intracellular Signaling in Muscle and Fat Cells During Ketosis
Study Details
Study Description
Brief Summary
Hypothesis
-
To define whether stimulation of ATGL and suppression of G0/G1 switch gene occur in the initial phases of diabetic ketoacidosis and thus can be identified as the primary mechanisms behind this life threatening condition.
-
Make a human model for studying ketoacidosis.
The investigators plan to reduce in their regular insulin over night. In the morning we administer endotoxin, which together with a relative lack of insulin will initiate ketogenesis - a state of ketoacidosis. On another occasion strict glycemic control is imposed by means of intravenous insulin. The testing is done two separate days with at least 3 weeks in between and patients are admitted to hospital the evening before the day of testing. The investigators use isotopic tracers to determine metabolic fluxes and analyse fat (ATGL, G0/G1 switch gene) and muscle biopsies.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Intervention Insulin reduction and mimic infection with LPS |
Biological: LPS
LPS is endotoxin from gram negative bacteria. It is used scientifically to mimic infection lasting 4-8 hours.
|
| No Intervention: Control Normal insulin and no LPS |
Outcome Measures
Primary Outcome Measures
- Insulin signaling expressed as a CHANGE in phosphorylation of intracellular target proteins and CHANGE in mRNA expression of target genes in muscle- and fat-tissue. [Muscle and fat biopsies obtained on each study day (arm): t1= 6.45 (-75min) am t2=11.15 (195min) am t3= 12.30 pm (270min)]
Change in phosphorylation of target proteins and messenger RNA (mRNA) expression of target genes assessed with western blotting technique.
Secondary Outcome Measures
- Change in Intracellular markers of lipid metabolism in muscle- and fat tissue biopsies [Muscle and fat biopsies obtained on each study day (arm): t1= 6.45 am (-75min) t2=11.15 (195min) am t3= 12.30 pm (270min)]
Muscle and fat at t1 and t2. Muscle biopsy at t3. Intracellular markers are assessed by western blotting.
- Metabolism [Change in glucose, fat and protein metabolism between study days and during each study day]
Change in glucose, fat and protein metabolism assessed by tracer kinetics on every study day (specific times below) and by indirect calorimetry. [3H 3]Glucose tracer from t=0 - 360min. Palmitic acid tracer from t=165min - 360min. Urea tracer from 0min - 240min. amino acid tracer from 60 min - 360 min.
- Cytokines and stress hormones [In basal period t=0-240 minutes and in clamp period t=240-390 minutes]
Measurement of immune response to endotoxin and hypoinsulinaemia. Estimating the whole body stress during ketoacidosis and pre ketoacidosis.
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Diabetes type 1
-
19 < BMI < 26
-
minimal or negative C-peptide
-
written consent
Exclusion Criteria:
-
Severe comorbidity
-
regular medication apart from insulin
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Aarhus University Hospital | Aarhus | Denmark | 8000 |
Sponsors and Collaborators
- University of Aarhus
Investigators
- Principal Investigator: Mads Svart, MD, Aarhus University / Aarhus University Hospital
- Study Chair: Niels Møller, MD, Aarhus University / Aarhus University Hospital
Study Documents (Full-Text)
None provided.More Information
Publications
- Andreasen AS, Krabbe KS, Krogh-Madsen R, Taudorf S, Pedersen BK, Møller K. Human endotoxemia as a model of systemic inflammation. Curr Med Chem. 2008;15(17):1697-705. Review.
- Bezaire V, Mairal A, Ribet C, Lefort C, Girousse A, Jocken J, Laurencikiene J, Anesia R, Rodriguez AM, Ryden M, Stenson BM, Dani C, Ailhaud G, Arner P, Langin D. Contribution of adipose triglyceride lipase and hormone-sensitive lipase to lipolysis in hMADS adipocytes. J Biol Chem. 2009 Jul 3;284(27):18282-91. doi: 10.1074/jbc.M109.008631. Epub 2009 May 11.
- Burge MR, Garcia N, Qualls CR, Schade DS. Differential effects of fasting and dehydration in the pathogenesis of diabetic ketoacidosis. Metabolism. 2001 Feb;50(2):171-7.
- Burge MR, Hardy KJ, Schade DS. Short-term fasting is a mechanism for the development of euglycemic ketoacidosis during periods of insulin deficiency. J Clin Endocrinol Metab. 1993 May;76(5):1192-8.
- Cahill GF Jr. Fuel metabolism in starvation. Annu Rev Nutr. 2006;26:1-22. Review.
- Haemmerle G, Lass A, Zimmermann R, Gorkiewicz G, Meyer C, Rozman J, Heldmaier G, Maier R, Theussl C, Eder S, Kratky D, Wagner EF, Klingenspor M, Hoefler G, Zechner R. Defective lipolysis and altered energy metabolism in mice lacking adipose triglyceride lipase. Science. 2006 May 5;312(5774):734-7.
- Nielsen TS, Vendelbo MH, Jessen N, Pedersen SB, Jørgensen JO, Lund S, Møller N. Fasting, but not exercise, increases adipose triglyceride lipase (ATGL) protein and reduces G(0)/G(1) switch gene 2 (G0S2) protein and mRNA content in human adipose tissue. J Clin Endocrinol Metab. 2011 Aug;96(8):E1293-7. doi: 10.1210/jc.2011-0149. Epub 2011 May 25.
- Sanchez-Cantu L, Rode HN, Christou NV. Endotoxin tolerance is associated with reduced secretion of tumor necrosis factor. Arch Surg. 1989 Dec;124(12):1432-5; discussion 1435-6.
- Schweiger M, Schreiber R, Haemmerle G, Lass A, Fledelius C, Jacobsen P, Tornqvist H, Zechner R, Zimmermann R. Adipose triglyceride lipase and hormone-sensitive lipase are the major enzymes in adipose tissue triacylglycerol catabolism. J Biol Chem. 2006 Dec 29;281(52):40236-41. Epub 2006 Oct 30.
- West MA, Heagy W. Endotoxin tolerance: A review. Crit Care Med. 2002 Jan;30(1 Supp):S64-S73.
- Yang X, Lu X, Lombès M, Rha GB, Chi YI, Guerin TM, Smart EJ, Liu J. The G(0)/G(1) switch gene 2 regulates adipose lipolysis through association with adipose triglyceride lipase. Cell Metab. 2010 Mar 3;11(3):194-205. doi: 10.1016/j.cmet.2010.02.003.
- Zimmermann R, Strauss JG, Haemmerle G, Schoiswohl G, Birner-Gruenberger R, Riederer M, Lass A, Neuberger G, Eisenhaber F, Hermetter A, Zechner R. Fat mobilization in adipose tissue is promoted by adipose triglyceride lipase. Science. 2004 Nov 19;306(5700):1383-6.
- 1-10-72-98-14