Modulation of Cannabinoid Receptors 1 Signaling Alleviated Diabetic Nephropathy

Diabetic nephropathy is a leading cause of end-stage renal disease in Taiwan. We have previously demonstrated the important role of embryonic stem cell signaling including DKK1/Wnt and Notch1 signaling in diabetic nephropathy. Type 1 and 2 cannabinoid receptors (CB) are bioactive molecules in Gi/o-protein-coupled receptor family. Modulation of CB signaling is found to control obesity-mediated metabolic disorders and tissue deterioration. In clinical vignettes, illicit drug use is a potent risk factor of chronic kidney disease and end-stage renal disease. Patients with mutated CB1 polymorphism are associated with renal microvascular damage. However, the biological role of CB1 signaling in diabetes-induced extracelluar matrix accumulation and renal dysfunction has not been addressed. We have preliminarily found that diabetes increased TGF-?1-mediated fibrosis and decreased PPAR? expression in association with increased CB1 expression when we harvested glomeruli mesangli in animal kidney using laser capture micro-dissection. We hypothesized that cannabinoid receptor signaling transduction participate in diabetes-induced fibrotic matrix accumulation in renal glomerular mesangli. Modulation of CB1 signaling may be an innovative strategy for preventing diabetic nephropathy. The rationale and specific aims of the current project are outlined below: Specific aim 1: Employing diabetic animal models, we elucidate the biological role of CB1 signaling and fibrogenic factor including PPAR-?, in regulating diabetes -promoted renal fibrosis in diabetic animal model. Furthermore, we use CB1 agonist (WIN55212-2) in normal animal and create transgenic CB1 mice to mimic diabetic kidney to see whether or not the same story in kidney also occur in this animal model. Specific aim 2: We explore whether anti-sense CB1 oligonucleotide therapy can rescue diabetic milieu-induced renal ECM accumulation and glomerulosclerosis in diabetic animal models. We also use pharmacological modulation by CB1 antagonist (AM251) to treat diabetic animal model to confirm our theory. Specific aim 3: We attempt to delineate pathologic role of CB1 signaling components via manipulating CB1, PPAR-gamma and ras/ERK signaling including anti-sense oligonucleotide, RNA interference, cDNA plasmid and dominant negative mutant in high glucose-induced fibrosis of renal cells. We also use PPAR-? agonist (Rosiglitazone) to treat diabetic animal model to define the interaction between PPAR-? and CB1 signaling. Anticipated results: We anticipate that control of CB1 signaling in renal tissue will be an innovative potential for preventing renal tissue against high glucose stress. Diabetes Kidney tissue CB1 activation WIN55212-2 or (Transgenic mice) (Transgenic mice) Anti-sense ODN or AM251 (CB1 antagonist) Ras dominant negative Ras/ERK signaling mutant PD98059 SiRNA PPAR--?2 depression cDNA and Rosiglitazone Diabetic nephropathy (TGF- β-mediated renal fibrosis) Figure Proposed Scheme for cannabinoid receptor modulation of PPAR--?-mediated diabetic nephropathy.

Project ID:PC10107-0376
External Project ID:NSC101-2314-B182-044-MY3