FR167653 inhibits fibronectin expression and apoptosis in diabetic glomeruli and in high-glucose-stimulated mesangial cells.
Previous in vitro studies suggest that the p38 MAPK pathway may be involved in the pathogenesis of diabetic nephropathy, but the consequences of the inhibition of the p38 MAPK pathway have not been well elucidated in diabetic (DM) glomeruli. This study was undertaken to investigate the effect of p38 MAPK inhibitor, FR167653, on fibronectin expression and apoptosis in DM glomeruli and in high-glucose-stimulated mesangial cells (MC). In vivo, 32 Sprague-Dawley rats were injected with diluent (control, N = 16) or streptozotocin intraperitoneally (DM, N = 16). Eight rats from each group were treated with FR167653 for 3 mo. In vitro, rat MC were exposed to medium containing 5.6 mM glucose or 30 mM glucose [high glucose (HG)] with or without 10(-6) M FR167653 for 24 h. Fibronectin mRNA and protein expression were determined by real-time PCR and Western blot, respectively. Western blot for apoptosis-related molecules, terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling assay, and Hoechst 33342 staining were performed to determine apoptosis. FR167653 ameliorated the increases in fibronectin-to-GAPDH mRNA ratio and protein expression in DM glomeruli by 89 and 79% and in HG-stimulated MC by 70 and 91%, respectively (P < 0.05). Under diabetic conditions, Bcl-2 protein expression was decreased, whereas cleaved caspase-3 protein expression was increased (P < 0.05), and these changes were inhibited by FR167653 treatment. Apoptotic cells were also significantly increased in DM glomeruli and in HG-stimulated MC (P < 0.05), and FR167653 ameliorated these increases in apoptotic cells, both in vivo and in vitro. In conclusion, these findings suggest that the inhibition of the p38 MAPK pathway has a beneficial effect on the development of diabetic nephropathy by inhibiting the increase in fibronectin expression and apoptosis.
Department of Internal Medicine, College of Medicine, Brain Korea 21 for Medical Science, Yonsei University, Seoul, Korea.
Dong-Sub
DS
Jung
Jin Ji
JJ
Li
Seung-Jae
SJ
Kwak
Sun Ha
SH
Lee
Jehyun
J
Park
Young Soo
YS
Song
Tae-Hyun
TH
Yoo
Seung Hyeok
SH
Han
Jung Eun
JE
Lee
Dong Ki
DK
Kim
Sung Jin
SJ
Moon
Yu Seun
YS
Kim
Dae Suk
DS
Han
Shin-Wook
SW
Kang
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005353:Fibronectins / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology*; D006943:Hyperglycemia / Q000378:metabolism / Q000473:pathology; D007678:Kidney Glomerulus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008297:Male; D050527:Mesangial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D013311:Streptozocin; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
D017362:Cyclic AMP Response Element-Binding Protein; D004791:Enzyme Inhibitors; C104334:FR 167653; D005353:Fibronectins; D019253:Proto-Oncogene Proteins c-bcl-2; D011720:Pyrazoles; D011725:Pyridines; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D013311:Streptozocin; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3; D005947:Glucose