Effects of immunosuppressive drugs on human adipose tissue metabolism

.......................................................................................................................................... 5 List of papers .................................................................................................................................. 6 List of abbreviations ...................................................................................................................... 7 Table of contents ............................................................................................................................ 8 Introduction .................................................................................................................................... 9 Insulin resistance and diabetes ................................................................................................................. 9 Type 2 diabetes ..................................................................................................................................... 9 Drug-induced diabetes ........................................................................................................................ 10 Complications of diabetes ................................................................................................................... 10 Immunosuppressive drugs and adverse metabolic effects ....................................................................... 11 New-onset diabetes after transplantation (NODAT) ........................................................................... 11 Dyslipidemia ........................................................................................................................................ 13 Adipose tissue .......................................................................................................................................... 13 Storage of triglycerides........................................................................................................................ 14 Adipose tissue as an endocrine organ ................................................................................................. 16 Adipose tissue distribution and metabolic disease ............................................................................. 16 Insulin action in adipose tissue ............................................................................................................... 17 Glucocorticoids ....................................................................................................................................... 19 The calcineurin inhibitors, cyclosporin A and tacrolimus ...................................................................... 21 Effects of calcineurin inhibitors on glucose and lipid metabolism ...................................................... 21 The mTOR inhibitor rapamycin............................................................................................................... 22 mTOR signalling ................................................................................................................................... 23 Effects of mTOR signalling in adipose tissue: adipogenesis and lipid storage .................................... 25 Effects of rapamycin on glucose and lipid metabolism ....................................................................... 25 Aims ............................................................................................................................................... 27 Methods ......................................................................................................................................... 28 Subjects and samples ............................................................................................................................... 28 Adipocyte isolation and fat cell size ........................................................................................................ 29 Adipocyte and adipose tissue incubation ................................................................................................ 29 Glucose uptake assay .............................................................................................................................. 30 Protein extraction and immunoblotting ................................................................................................... 31 Gene expression ...................................................................................................................................... 32 Microarray ........................................................................................................................................... 32 Real-time PCR ...................................................................................................................................... 32 Lipolysis and lipid storage ...................................................................................................................... 33 GLUT4 trafficking in L6 cells.................................................................................................................. 33 Statistical analyses .................................................................................................................................. 34 Summary of results ...................................................................................................................... 35 Paper I ..................................................................................................................................................... 35 Paper II.................................................................................................................................................... 36 Paper III .................................................................................................................................................. 36 Paper IV .................................................................................................................................................. 38 Discussion ...................................................................................................................................... 39 Effects of rapamycin, cyclosporin A and tacrolimus on glucose uptake ................................................. 39 Effects of rapamycin, cyclosporin A and tacrolimus on insulin signalling ............................................. 41 Effects of rapamycin, cyclosporin A and tacrolimus on lipid metabolism .............................................. 44 Effects of dexamethasone on adipose tissue gene expression ................................................................. 46 Concluding remarks .................................................................................................................... 49 Acknowledgements ....................................................................................................................... 50 References ..................................................................................................................................... 52