| First Author | Mohamed R | Year | 2013 |
| Journal | Lab Invest | Volume | 93 |
| Issue | 8 | Pages | 933-45 |
| PubMed ID | 23817085 | Mgi Jnum | J:198806 |
| Mgi Id | MGI:5499248 | Doi | 10.1038/labinvest.2013.85 |
| Citation | Mohamed R, et al. (2013) Chronic administration of EP4-selective agonist exacerbates albuminuria and fibrosis of the kidney in streptozotocin-induced diabetic mice through IL-6. Lab Invest 93(8):933-45 |
| abstractText | Diabetic nephropathy is currently the most common cause of end-stage renal disease in the western world. Exacerbated inflammation of the kidney is known to contribute acceleration of nephropathy. Despite increased COX-2-mediated production of prostanoid metabolite PGE2, knowledge on its involvement in the progression of diabetic kidney disease is not complete. Here, we show the cross talk of the PGE2-EP4 pathways and IL-6 in inducing albuminuria and fibrosis in an animal model of type 1 diabetes. Hyperglycemia causes enhanced COX-2 expression and PGE2 production. Administration of PGE2 receptor EP4-selective agonist ONO-AE1-329 for 12 weeks exacerbated fibrosis and albuminuria. Diabetes-induced expression of inflammatory cytokines TNFalpha and TGFbeta1 was enhanced in EP4 agonist-treated mice kidney. In addition, urinary excretion of cytokines (TNFalpha and IL-6) and chemokines (MCP-1 and IP-10) were significantly more in EP4-treated mice than vehicle-treated diabetes. Diabetes-induced collagen I and CTGF expression were also significantly higher in EP4-treated mice. However, EP4 agonist did not alter macrophage infiltration but increased cytokine and chemokine production in RAW264.7 cells. Interestingly, EP4-induced IL-6 expression in the kidney was localized in proximal and distal tubular epithelial cells. To confirm further whether EP4 agonist increases fibrosis and albuminuria through an increase in IL-6 expression, IL-6-knockout mice were administered with EP4 agonist. IL-6-knockout mice were resistant to EP4-induced exacerbation of albuminuria and diabetes and EP4-induced fibrosis. Our data suggest that EP4 agonist through IL-6 induces glomerulosclerosis and interstitial fibrosis, and IL-6 represents a new factor in the EP4 pathway. |
