Although more boys were admitted to the PICU, a significantly higher number of girls died. Younger age and higher occurrence of nosocomial infection among girls could explain this finding. More frequent polytraumatic injuries in boys could reflect an increased exposure to risky activities and/or more careless behavior.
We examined the effects of VEGFA on damage and regeneration in steatotic and non-steatotic livers of rats submitted to PH under I/R, and characterized the underlying mechanisms involved. Our results indicated that VEGFA levels were decreased in both steatotic and non-steatotic livers after surgery. The administration of VEGFA increased VEGFA levels in non-steatotic livers, reducing the incidence of post-operative complications following surgery through the VEGFR2-Wnt2 pathway, independently of Id1. Unexpectedly, administration of VEGFA notably reduced VEGFA levels in steatotic livers, exacerbating damage and regenerative failure. After exogenous administration of VEGFA in steatotic animals, circulating VEGFA is sequestered by the high circulating levels of sFlt1 released from adipose tissue. Under such conditions, VEGFA cannot reach the steatotic liver to exert its effects. Consequently, the concomitant administration of VEGFA and an antibody against sFlt1 was required to avoid binding of sFlt1 to VEGFA. This was associated with high VEGFA levels in steatotic livers and protection against damage and regenerative failure, plus improvement in the survival rate via up-regulation of PI3K/Akt independently of the Id1-Wnt2 pathway. The current study highlights the different effects and signaling pathways of VEGFA in liver surgery requiring PH and I/R based in the presence of steatosis.
Key messages
VEGFA administration improves PH+I/R injury only in non-steatotic livers of Ln animals.
VEGFA benefits are exerted through the VEGFR2-Wnt2 pathway in non-steatotic livers.
In Ob rats, exogenous VEGFA is sequestered by circulating sFlt1, exacerbating liver damage.
Therapeutic combination of VEGFA and anti-sFlt1 is required to protect steatotic livers.
VEGFA+anti-sFlt1 treatment protects steatotic livers through a VEGFR2-PI3K/Akt pathway.
Electronic supplementary material
The online version of this article (10.1007/s00109-019-01811-y) contains supplementary material, which is available to authorized users.
† These authors contributed equally to this work.High-mobility group box 1 (HMGB1) has been described in different inflammatory disorders, and the deleterious effects of brain death (BD) may counteract the protection conferred by ischemic preconditioning (IP), the only surgical strategy that is being applied in clinical liver transplantation. Our study examined how HMGB1 may affect preconditioned and unpreconditioned steatotic and nonsteatotic liver grafts from donors after BD (DBDs) for transplantation. HMGB1 was pharmacologically modulated in liver grafts from DBDs, and HMGB1-underlying mechanisms were characterized. We found that BD decreased HMGB1 in preconditioned and unpreconditioned livers and was associated with inflammation and damage. Exogenous HMGB1 in DBDs activates phosphoinositide-3-kinase and Akt and reduces hepatic inflammation and damage, increasing the survival of recipients. Combination of IP and exogenous HMGB1 shows additional benefits compared with HMGB1 alone. This study provides new mechanistic insights into the pathophysiology of BD-derived liver graft damage and contributes to the development of novel and efficient strategies to ultimately improve liver graft quality.
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