Abstract
Renal growth, particularly hypertrophy, is a feature of diabetic nephropathy (DN).
Adiponectin, an adipocyte-derived hormone, is an important regulator of cell proliferation.
Recent studies have suggested that adiponectin has a protective effect in the kidney.
The purpose of this study was to investigate the therapeutic effects and the underlying
mechanisms of adiponectin in early DN. Mouse mesangial cells (MMCs) were cultured
in media containing different concentrations of platelet-derived growth factor-BB
(PDGF-BB) with or without adiponectin. MMC proliferation and expression of type IV
collagen, laminin, and fibronectin were investigated. Streptozotocin-induced diabetic
mice were injected intravenously with recombinant lentivirus encoding the mouse adiponectin
gene (Lenti-Acdc-IRES-EGFP). Urinary microalbumin, serum adiponectin level, and expression
of proliferating cell nuclear antigen, type IV collagen, laminin, and fibronectin
were determined. Adiponectin inhibited the increases in MMC proliferation and expression
of type IV collagen, laminin, and fibronectin induced by PDGF-BB. Adiponectin also
effectively reduced renal cell proliferation and expression of type IV collagen, laminin,
and fibronectin when it was introduced in vivo by lentivirus-mediated gene transfer.
These findings suggest that adiponectin exerts renoprotective effects by inhibiting
renal cell proliferation and reducing synthesis of extracellular matrix proteins,
thus suppressing the development and progression of DN.
Key words adiponectin - diabetic nephropathy - lentivirus - extracellular matrix proteins