TY - JOUR
T1 - The Macrophage Phagocytic Receptor CD36 Promotes Fibrogenic Pathways on Removal of Apoptotic Cells during Chronic Kidney Injury
AU - Pennathur, Subramaniam
AU - Pasichnyk, Katie
AU - Bahrami, Nadia M.
AU - Zeng, Lixia
AU - Febbraio, Maria
AU - Yamaguchi, Ikuyo
AU - Okamura, Daryl M.
N1 - Funding Information:
Supported by NIH grants 5 K08 DK073497 (D.M.O.), 5 R03 DK083648 (D.M.O.), DK082841 (S.P.), DK081943 (S.P.), and DK89503 (S.P.) and the National Kidney Foundation Young Investigator award (D.M.O.).
Publisher Copyright:
© 2015 American Society for Investigative Pathology.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - The removal of apoptotic cells is an innate function of tissue macrophages; however, its role in disease progression is unclear. The present study was designed to investigate the role of macrophage CD36, a recognized receptor of apoptotic cells and oxidized lipids, in two models of kidney injury: unilateral ureteral obstruction (UUO) and ischemia reperfusion. To differentiate the macrophage CD36-specific effects in vivo, we generated CD36 chimeric mice by bone marrow transplantation and evaluated the two models. Fibrosis severity was substantially decreased after UUO with a corresponding decrease in matrix synthesis in macrophage CD36-deficient mice. Despite a reduction in fibrosis severity, a 56% increase in apoptotic cells was found without an increase in apoptotic effectors. In addition, a substantial reduction was observed in tumor necrosis factor-α and transforming growth factor-β1 mRNA levels and intracellular bioactive oxidized lipid levels in CD36-deficient macrophages. To validate the functional role of macrophage CD36, we performed unilateral ischemia reperfusion, followed by contralateral nephrectomy. Similarly, we found that the severity of fibrosis was reduced by 55% with a corresponding improvement in kidney function by 88% in macrophage CD36-deficient mice. Taken together, these data suggest that macrophage CD36 is a critical regulator of oxidative fibrogenic signaling and that CD36-mediated phagocytosis of apoptotic cells may serve as an important pathway in the progression of fibrosis.
AB - The removal of apoptotic cells is an innate function of tissue macrophages; however, its role in disease progression is unclear. The present study was designed to investigate the role of macrophage CD36, a recognized receptor of apoptotic cells and oxidized lipids, in two models of kidney injury: unilateral ureteral obstruction (UUO) and ischemia reperfusion. To differentiate the macrophage CD36-specific effects in vivo, we generated CD36 chimeric mice by bone marrow transplantation and evaluated the two models. Fibrosis severity was substantially decreased after UUO with a corresponding decrease in matrix synthesis in macrophage CD36-deficient mice. Despite a reduction in fibrosis severity, a 56% increase in apoptotic cells was found without an increase in apoptotic effectors. In addition, a substantial reduction was observed in tumor necrosis factor-α and transforming growth factor-β1 mRNA levels and intracellular bioactive oxidized lipid levels in CD36-deficient macrophages. To validate the functional role of macrophage CD36, we performed unilateral ischemia reperfusion, followed by contralateral nephrectomy. Similarly, we found that the severity of fibrosis was reduced by 55% with a corresponding improvement in kidney function by 88% in macrophage CD36-deficient mice. Taken together, these data suggest that macrophage CD36 is a critical regulator of oxidative fibrogenic signaling and that CD36-mediated phagocytosis of apoptotic cells may serve as an important pathway in the progression of fibrosis.
UR - http://www.scopus.com/inward/record.url?scp=84937849409&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84937849409&partnerID=8YFLogxK
U2 - 10.1016/j.ajpath.2015.04.016
DO - 10.1016/j.ajpath.2015.04.016
M3 - Article
C2 - 26092500
AN - SCOPUS:84937849409
VL - 185
SP - 2232
EP - 2245
JO - American Journal of Pathology
JF - American Journal of Pathology
SN - 0002-9440
IS - 8
ER -