TY - JOUR
T1 - CD40 enhances sphingolipids in orbital fibroblasts
T2 - Potential role of sphingosine-1-phosphate in inflammatory T-cell migration in Graves’ orbitopathy
AU - Plöhn, Svenja
AU - Edelmann, Bärbel
AU - Japtok, Lukasz
AU - He, Xingxuan
AU - Hose, Matthias
AU - Hansen, Wiebke
AU - Schuchman, Edward H.
AU - Eckstein, Anja
AU - Berchner-Pfannschmidt, Utta
N1 - Publisher Copyright:
© 2018 The Authors.
PY - 2018/11
Y1 - 2018/11
N2 - PURPOSE. Graves’ orbitopathy (GO) is an autoimmune orbital disorder associated with Graves’ disease caused by thyrotropin receptor autoantibodies. Orbital fibroblasts (OFs) and CD40 play a key role in disease pathogenesis. The bioactive lipid sphingosine-1-phosphate (S1P) has been implicated in promoting adipogenesis, fibrosis, and inflammation in OFs. We investigated the role of CD40 signaling in inducing S1P activity in orbital inflammation. METHOD S . OFs and T cells were derived from GO patients and healthy control (Ctl) persons. S1P abundance in orbital tissues was evaluated by immunofluorescence. OFs were stimulated with CD40 ligand and S1P levels were determined by ELISA. Further, activities of acid sphingomyelinase (ASM), acid ceramidase, and sphingosine kinase were measured by ultraperformance liquid chromatography. Sphingosine and ceramide contents were analyzed by mass spectrometry. Finally, the role for S1P in T-cell attraction was investigated by T-cell migration assays. RESULTS. GO orbital tissue showed elevated amounts of S1P as compared to control samples. Stimulation of CD40 induced S1P expression in GO-derived OFs, while Ctl-OFs remained unaffected. A significant increase of ASM and sphingosine kinase activities, as well as lipid formation, was observed in GO-derived OFs. Migration assay of T cells in the presence of SphK inhibitor revealed that S1P released by GO-OFs attracted T cells for migration. CONCLUSIONS. The results demonstrated that CD40 ligand stimulates GO fibroblast to produce S1P, which is a driving force for T-cell migration. The results support the use of S1P receptor signaling modulators in GO management.
AB - PURPOSE. Graves’ orbitopathy (GO) is an autoimmune orbital disorder associated with Graves’ disease caused by thyrotropin receptor autoantibodies. Orbital fibroblasts (OFs) and CD40 play a key role in disease pathogenesis. The bioactive lipid sphingosine-1-phosphate (S1P) has been implicated in promoting adipogenesis, fibrosis, and inflammation in OFs. We investigated the role of CD40 signaling in inducing S1P activity in orbital inflammation. METHOD S . OFs and T cells were derived from GO patients and healthy control (Ctl) persons. S1P abundance in orbital tissues was evaluated by immunofluorescence. OFs were stimulated with CD40 ligand and S1P levels were determined by ELISA. Further, activities of acid sphingomyelinase (ASM), acid ceramidase, and sphingosine kinase were measured by ultraperformance liquid chromatography. Sphingosine and ceramide contents were analyzed by mass spectrometry. Finally, the role for S1P in T-cell attraction was investigated by T-cell migration assays. RESULTS. GO orbital tissue showed elevated amounts of S1P as compared to control samples. Stimulation of CD40 induced S1P expression in GO-derived OFs, while Ctl-OFs remained unaffected. A significant increase of ASM and sphingosine kinase activities, as well as lipid formation, was observed in GO-derived OFs. Migration assay of T cells in the presence of SphK inhibitor revealed that S1P released by GO-OFs attracted T cells for migration. CONCLUSIONS. The results demonstrated that CD40 ligand stimulates GO fibroblast to produce S1P, which is a driving force for T-cell migration. The results support the use of S1P receptor signaling modulators in GO management.
KW - Grave’s orbitopathy
KW - Inflammation
KW - Sphingolipids
KW - Sphingosine-1-phosphate
UR - http://www.scopus.com/inward/record.url?scp=85056720644&partnerID=8YFLogxK
U2 - 10.1167/iovs.18-25466
DO - 10.1167/iovs.18-25466
M3 - Article
C2 - 30452592
AN - SCOPUS:85056720644
SN - 0146-0404
VL - 59
SP - 5391
EP - 5397
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 13
ER -