The role of interstitial macrophages in nephropathy of type 2 diabetic db/db mice.
Diabetic nephropathy is associated with interstitial macrophage infiltrates, but their contribution to disease progression is unclear. We addressed this question by blockade of chemokine receptor (CCR)1 because CCR1 mediates the macrophage recruitment to the renal interstitium. In fact, when CCR1 was blocked with BL5923, a novel orally available CCR1 antagonist, the interstitial recruitment of ex vivo labeled macrophages was markedly decreased in uninephrectomized male db/db mice with advanced diabetic nephropathy. Likewise, BL5923 (60 mg/kg, twice a day) orally administered from months 5 to 6 of life reduced the numbers of interstitial macrophages in uninephrectomized db/db mice. This was associated with reduced numbers of Ki-67 proliferating tubular epithelial and interstitial cells, tubular atrophy, and interstitial fibrosis in uninephrectomized db/db mice. Glomerular pathology and proteinuria were not affected by the CCR1 antagonist. BL5923 reduced renal mRNA expression of Ccl2, Ccr1, Ccr2, Ccr5, transforming growth factor-beta1, and collagen I-alpha1 when compared with untreated uninephrectomized male db/db mice of the same age. Thus, we identified a previously unrecognized role for interstitial macrophages for tubulointerstitial injury, loss of peritubular microvasculature, interstitial inflammation, and fibrosis in type 2 diabetic db/db mice. These data identify oral treatment with the CCR1 antagonist BL5923 as a potential therapy for late-stage diabetic nephropathy.
Ninichuk
Volha
V
Medizinische Poliklinik, Klinikum der Universität München-Innenstadt, Pettenkoferstr. 8a, 80336 Munchen, Germany.
Khandoga
Alexander G
AG
Segerer
Stephan
S
Loetscher
Pius
P
Schlapbach
Achim
A
Revesz
Laszlo
L
Feifel
Roland
R
Khandoga
Andrej
A
Krombach
Fritz
F
Nelson
Peter J
PJ
Schlöndorff
Detlef
D
Anders
Hans-Joachim
HJ
D000284:Administration, Oral; D000818:Animals; D000943:Antigens, Differentiation / Q000032:analysis; D002460:Cell Line; D002478:Cells, Cultured; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003929:Diabetic Neuropathies / Q000209:etiology / Q000473:pathology*; D015870:Gene Expression / Q000187:drug effects; D007150:Immunohistochemistry; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007678:Kidney Glomerulus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008264:Macrophages / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D008856:Microscopy, Fluorescence; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D054389:Receptors, CCR1; D054390:Receptors, CCR2; D019707:Receptors, Chemokine / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053773:Transforming Growth Factor beta1 / Q000235:genetics
D000943:Antigens, Differentiation; C515301:Ccr1 protein, mouse; C515335:Ccr2 protein, mouse; D012333:RNA, Messenger; D054389:Receptors, CCR1; D054390:Receptors, CCR2; D019707:Receptors, Chemokine; D053773:Transforming Growth Factor beta1; C036763:monocyte-macrophage differentiation antigen