TY - JOUR
T1 - Endothelial Poldip2 regulates sepsis-induced lung injury via Rho pathway activation
AU - Dolmatova, Elena V.
AU - Forrester, Steven J.
AU - Wang, Keke
AU - Ou, Ziwei
AU - Williams, Holly C.
AU - Joseph, Giji
AU - Kumar, Sandeep
AU - Valdivia, Alejandra
AU - Kowalczyk, Andrew P.
AU - Qu, Hongyan
AU - Jo, Hanjoong
AU - Lassègue, Bernard
AU - Hernandes, Marina S.
AU - Griendling, Kathy K.
N1 - Publisher Copyright:
© 2021 Published on behalf of the European Society of Cardiology. All rights reserved.
PY - 2022/7/1
Y1 - 2022/7/1
N2 - Aims: Sepsis-induced lung injury is associated with significant morbidity and mortality. Previously, we showed that heterozygous deletion of polymerase d-interacting protein 2 (Poldip2) was protective against sepsis-induced lung injury. Since endothelial barrier disruption is thought to be the main mechanism of sepsis-induced lung injury, we sought to determine if the observed protection was specifically due to the effect of reduced endothelial Poldip2. Methods and results: Endothelial-specific Poldip2 knock-out mice (EC-/-) and their wild-type littermates (EC+/+) were injected with saline or lipopolysaccharide (18 mg/kg) to model sepsis-induced lung injury. At 18 h post-injection mice, were euthanized and bronchoalveolar lavage (BAL) fluid and lung tissue were collected to assess leucocyte infiltration. Poldip2 EC-/- mice showed reduced lung leucocyte infiltration in BAL (0.21 ± 0.9×106 vs. 1.29 ± 1.8×106 cells/mL) and lung tissue (12.7 ± 1.8 vs. 23 ± 3.7% neutrophils of total number of cells) compared to Poldip2 EC+/+ mice. qPCR analysis of the lung tissue revealed a significantly dampened induction of inflammatory gene expression (TNFa 2.23 ± 0.39 vs. 4.15 ± 0.5-fold, I?Ba 4.32 ± 1.53 vs. 8.97 ± 1.59-fold), neutrophil chemoattractant gene expression (CXCL1 68.8 ± 29.6 vs. 147 ± 25.7-fold, CXCL2 65 ± 25.6 vs. 215 ± 27.3-fold) and a marker of endothelial activation (VCAM1 1.25 ± 0.25 vs. 3.8 ± 0.38-fold) in Poldip2 EC-/- compared to Poldip2 EC+/+ lungs. An in vitro model using human pulmonary microvascular endothelial cells was used to assess the effect of Poldip2 knock-down on endothelial activation and permeability. TNFa-induced endothelial permeability and VE-cadherin disruption were significantly reduced with siRNA-mediated knock-down of Poldip2 (5 ± 0.5 vs. 17.5 ± 3-fold for permeability, 1.5 ± 0.4 vs. 10.9 ± 1.3-fold for proportion of disrupted VE-cadherin). Poldip2 knock-down altered expression of Rho-GTPase-related genes, which correlated with reduced RhoA activation by TNFa (0.94 ± 0.05 vs. 1.29 ± 0.01 of relative RhoA activity) accompanied by redistribution of active-RhoA staining to the centre of the cell. Conclusion: Poldip2 is a potent regulator of endothelial dysfunction during sepsis-induced lung injury, and its endothelium-specific inhibition may provide clinical benefit.
AB - Aims: Sepsis-induced lung injury is associated with significant morbidity and mortality. Previously, we showed that heterozygous deletion of polymerase d-interacting protein 2 (Poldip2) was protective against sepsis-induced lung injury. Since endothelial barrier disruption is thought to be the main mechanism of sepsis-induced lung injury, we sought to determine if the observed protection was specifically due to the effect of reduced endothelial Poldip2. Methods and results: Endothelial-specific Poldip2 knock-out mice (EC-/-) and their wild-type littermates (EC+/+) were injected with saline or lipopolysaccharide (18 mg/kg) to model sepsis-induced lung injury. At 18 h post-injection mice, were euthanized and bronchoalveolar lavage (BAL) fluid and lung tissue were collected to assess leucocyte infiltration. Poldip2 EC-/- mice showed reduced lung leucocyte infiltration in BAL (0.21 ± 0.9×106 vs. 1.29 ± 1.8×106 cells/mL) and lung tissue (12.7 ± 1.8 vs. 23 ± 3.7% neutrophils of total number of cells) compared to Poldip2 EC+/+ mice. qPCR analysis of the lung tissue revealed a significantly dampened induction of inflammatory gene expression (TNFa 2.23 ± 0.39 vs. 4.15 ± 0.5-fold, I?Ba 4.32 ± 1.53 vs. 8.97 ± 1.59-fold), neutrophil chemoattractant gene expression (CXCL1 68.8 ± 29.6 vs. 147 ± 25.7-fold, CXCL2 65 ± 25.6 vs. 215 ± 27.3-fold) and a marker of endothelial activation (VCAM1 1.25 ± 0.25 vs. 3.8 ± 0.38-fold) in Poldip2 EC-/- compared to Poldip2 EC+/+ lungs. An in vitro model using human pulmonary microvascular endothelial cells was used to assess the effect of Poldip2 knock-down on endothelial activation and permeability. TNFa-induced endothelial permeability and VE-cadherin disruption were significantly reduced with siRNA-mediated knock-down of Poldip2 (5 ± 0.5 vs. 17.5 ± 3-fold for permeability, 1.5 ± 0.4 vs. 10.9 ± 1.3-fold for proportion of disrupted VE-cadherin). Poldip2 knock-down altered expression of Rho-GTPase-related genes, which correlated with reduced RhoA activation by TNFa (0.94 ± 0.05 vs. 1.29 ± 0.01 of relative RhoA activity) accompanied by redistribution of active-RhoA staining to the centre of the cell. Conclusion: Poldip2 is a potent regulator of endothelial dysfunction during sepsis-induced lung injury, and its endothelium-specific inhibition may provide clinical benefit.
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U2 - 10.1093/cvr/cvab295
DO - 10.1093/cvr/cvab295
M3 - Article
C2 - 34528082
AN - SCOPUS:85137127606
SN - 0008-6363
VL - 118
SP - 2506
EP - 2518
JO - Cardiovascular Research
JF - Cardiovascular Research
IS - 11
ER -