Semaphorin 3F and NRP2 protein expression in placental tissues.

<p>Semaphorin 3F (A) and NRP2 (B) protein expression was analyzed by immunoblotting in placental tissues from both normal and preeclamptic subjects. Semaphorin 3F and NRP2 protein expression was significantly higher in normal placentae as compared to preeclamptic placentae. Quantification of semaphorin 3F and NRP2 protein expression is normalized to β-actin bands intensity. Data are represented as mean semaphorin 3F/β-actin and NRP2/β-actin ratio ± SD and are representative of the whole preeclampsia group and of 19 randomly selected women from the control group. (*) p = 0.04 for Semaphorin 3F and p = 0.03 for NRP2, respectively.</p

Main clinical features of mothers and newborns at delivery.

<p>The values are expressed as median (25^th-75^th percentile).</p

Semaphorin 3F, NRP2 and HIF1-alpha expression in placental tissues.

<p>Double-label immunofluorescence showing expression of semaphorin 3F (green) and CD31 (red) in the placenta of both normal (A-D) and preeclamptic (E-H) patients. To-pro-3 counter stains nuclei (blue). Merged images (yellow) demonstrate that semaphorin 3F was more expressed by CD31-positive endothelial cells in normal patients (A-D) than in preeclamptic patients (E-H). Double-label immunofluorescence showing expression of NRP2 (green) and CD31 (red) in the placenta of both normal (I-L) and preeclamptic (M-P) patients. To-pro-3 counter stains nuclei (blue). Merged images (yellow) demonstrate that NRP2 was highly expressed at endothelial level (I-L), while its expression was strongly reduced in preeclamptic placentae (M-P). Double-label immunofluorescence showing expression of HIF1 alpha (green) and CD31 (red) in the placental tissue of both normal (Q-T) and preeclamptic (U-X) patients. To-pro-3 counter stains nuclei (blue). Merged images (yellow) demonstrate that HIF1 alpha was absent in normal placentae (Q-T), while its expression was significantly increased in preeclamptic placentae (U-X). Specific semaphorin 3F immunofluorescence quantification (Y, left histogram) showed statistically significant difference in mean fluorescence intensity (MFI) between normal and preeclamptic patients. Quantification of specific NRP2 fluorescence (Y, center histogram) demonstrated that MFI of NRP2 in normal placentae was significantly higher than in preeclamptic placentae. Quantification of specific fluorescence (Y, right histogram) confirmed the absence of HIF1 alpha signal in normal placentae and its increased expression in preeclamptic placentae. Results are representative of 10 patients. (*) p<0.001.</p

Semaphorin 3F levels in maternal serum, cord blood and amniotic fluid at delivery.

<p>Semaphorin 3F levels were significantly higher in normal pregnant (n = 91) in comparison with preeclampsia patients (n = 19) in maternal serum (A), cord blood (B) and amniotic fluid (C) at delivery (2.01±0.33 vs. 2.92±0.55 ng/mL for serum samples, p<0.001; 131.70±36.20 vs. 198.18±83.51 ng/mL for amniotic fluid, p = 0.001; 0.58±0.27 vs. 0.92±0.20 ng/mL for cord blood, respectively, p = 0.038). Serum semaphorin 3F levels were also assessed in a cohort of non-pregnant health female controls (n = 40), which resulted comparable to preeclampsia patients (1.70±0.30 vs. 2.01±0.33 ng/mL, p = 0.06). (*) p<0.001 vs. normal women; (**) p<0.001 vs. normal women and p = 0.06 vs preeclampsia women; (^#) p = 0.02 vs. normal women.</p

Semaphorin 3F levels in amniotic fluid at amniocentesis.

<p>(A) Quantification of semaphorin 3F levels at amniocentesis showed significantly lower levels in the amniotic fluid in pregnant women subsequently developing preeclampsia as compared with women carrying out a normal pregnancy (9.08±7.7 vs. 30.85±15.81 ng/mL, p<0.001). (B) The ROC curve analysis confirmed the reliability of semaphorin 3F amniotic fluid levels to identify women at higher risk to develop preeclampsia (AUC 0.941, p<0.001) with a cut-off value of 18.35 ng/mL (B). (*) p<0.001.</p

image_4_Complement Activation During Ischemia/Reperfusion Injury Induces Pericyte-to-Myofibroblast Transdifferentiation Regulating Peritubular Capillary Lumen Reduction Through pERK Signaling.tif

<p>Pericytes are one of the principal sources of scar-forming myofibroblasts in chronic kidneys disease. However, the modulation of pericyte-to-myofibroblast transdifferentiation (PMT) in the early phases of acute kidney injury is poorly understood. Here, we investigated the role of complement in inducing PMT after transplantation. Using a swine model of renal ischemia/reperfusion (I/R) injury, we found the occurrence of PMT after 24 h of I/R injury as demonstrated by reduction of PDGFRβ⁺/NG2⁺ cells with increase in myofibroblasts marker αSMA. In addition, PMT was associated with significant reduction in peritubular capillary luminal diameter. Treatment by C1-inhibitor (C1-INH) significantly preserved the phenotype of pericytes maintaining microvascular density and capillary lumen area at tubulointerstitial level. In vitro, C5a transdifferentiated human pericytes in myofibroblasts, with increased αSMA expression in stress fibers, collagen I production, and decreased antifibrotic protein Id2. The C5a-induced PMT was driven by extracellular signal-regulated kinases phosphorylation leading to increase in collagen I release that required both non-canonical and canonical TGFβ pathways. These results showed that pericytes are a pivotal target of complement activation leading to a profibrotic maladaptive cellular response. Our studies suggest that C1-INH may be a potential therapeutic strategy to counteract the development of PMT and capillary lumen reduction in I/R injury.</p

image_1_Complement Activation During Ischemia/Reperfusion Injury Induces Pericyte-to-Myofibroblast Transdifferentiation Regulating Peritubular Capillary Lumen Reduction Through pERK Signaling.tif

<p>Pericytes are one of the principal sources of scar-forming myofibroblasts in chronic kidneys disease. However, the modulation of pericyte-to-myofibroblast transdifferentiation (PMT) in the early phases of acute kidney injury is poorly understood. Here, we investigated the role of complement in inducing PMT after transplantation. Using a swine model of renal ischemia/reperfusion (I/R) injury, we found the occurrence of PMT after 24 h of I/R injury as demonstrated by reduction of PDGFRβ⁺/NG2⁺ cells with increase in myofibroblasts marker αSMA. In addition, PMT was associated with significant reduction in peritubular capillary luminal diameter. Treatment by C1-inhibitor (C1-INH) significantly preserved the phenotype of pericytes maintaining microvascular density and capillary lumen area at tubulointerstitial level. In vitro, C5a transdifferentiated human pericytes in myofibroblasts, with increased αSMA expression in stress fibers, collagen I production, and decreased antifibrotic protein Id2. The C5a-induced PMT was driven by extracellular signal-regulated kinases phosphorylation leading to increase in collagen I release that required both non-canonical and canonical TGFβ pathways. These results showed that pericytes are a pivotal target of complement activation leading to a profibrotic maladaptive cellular response. Our studies suggest that C1-INH may be a potential therapeutic strategy to counteract the development of PMT and capillary lumen reduction in I/R injury.</p

image_2_Complement Activation During Ischemia/Reperfusion Injury Induces Pericyte-to-Myofibroblast Transdifferentiation Regulating Peritubular Capillary Lumen Reduction Through pERK Signaling.tif

<p>Pericytes are one of the principal sources of scar-forming myofibroblasts in chronic kidneys disease. However, the modulation of pericyte-to-myofibroblast transdifferentiation (PMT) in the early phases of acute kidney injury is poorly understood. Here, we investigated the role of complement in inducing PMT after transplantation. Using a swine model of renal ischemia/reperfusion (I/R) injury, we found the occurrence of PMT after 24 h of I/R injury as demonstrated by reduction of PDGFRβ⁺/NG2⁺ cells with increase in myofibroblasts marker αSMA. In addition, PMT was associated with significant reduction in peritubular capillary luminal diameter. Treatment by C1-inhibitor (C1-INH) significantly preserved the phenotype of pericytes maintaining microvascular density and capillary lumen area at tubulointerstitial level. In vitro, C5a transdifferentiated human pericytes in myofibroblasts, with increased αSMA expression in stress fibers, collagen I production, and decreased antifibrotic protein Id2. The C5a-induced PMT was driven by extracellular signal-regulated kinases phosphorylation leading to increase in collagen I release that required both non-canonical and canonical TGFβ pathways. These results showed that pericytes are a pivotal target of complement activation leading to a profibrotic maladaptive cellular response. Our studies suggest that C1-INH may be a potential therapeutic strategy to counteract the development of PMT and capillary lumen reduction in I/R injury.</p

image_3_Complement Activation During Ischemia/Reperfusion Injury Induces Pericyte-to-Myofibroblast Transdifferentiation Regulating Peritubular Capillary Lumen Reduction Through pERK Signaling.tif

<p>Pericytes are one of the principal sources of scar-forming myofibroblasts in chronic kidneys disease. However, the modulation of pericyte-to-myofibroblast transdifferentiation (PMT) in the early phases of acute kidney injury is poorly understood. Here, we investigated the role of complement in inducing PMT after transplantation. Using a swine model of renal ischemia/reperfusion (I/R) injury, we found the occurrence of PMT after 24 h of I/R injury as demonstrated by reduction of PDGFRβ⁺/NG2⁺ cells with increase in myofibroblasts marker αSMA. In addition, PMT was associated with significant reduction in peritubular capillary luminal diameter. Treatment by C1-inhibitor (C1-INH) significantly preserved the phenotype of pericytes maintaining microvascular density and capillary lumen area at tubulointerstitial level. In vitro, C5a transdifferentiated human pericytes in myofibroblasts, with increased αSMA expression in stress fibers, collagen I production, and decreased antifibrotic protein Id2. The C5a-induced PMT was driven by extracellular signal-regulated kinases phosphorylation leading to increase in collagen I release that required both non-canonical and canonical TGFβ pathways. These results showed that pericytes are a pivotal target of complement activation leading to a profibrotic maladaptive cellular response. Our studies suggest that C1-INH may be a potential therapeutic strategy to counteract the development of PMT and capillary lumen reduction in I/R injury.</p