Placental treatment with insulin-like growth factor 1 via nanoparticle differentially impacts vascular remodeling factors in guinea pig sub-placenta/decidua

Abstract

Clinically, fetal growth restriction (FGR) is only detectable in later gestation, despite pathophysiological establishment likely earlier in pregnancy. Additionally, there are no effective in utero treatment options for FGR. We have developed a nanoparticle to deliver human insulin-like 1 growth factor (hIGF-1) in a trophoblast-specific manner which results in increased expression of hIGF-1. IGF-1 signaling in the placenta regulates multiple developmental processes including trophoblast invasion and maternal vascular remodeling, both of which can be diminished in the FGR placenta. We aimed to determine the effects of short-term hIGF-1 nanoparticle treatment on sub-placenta/decidua trophoblast signaling mechanisms in FGR and under normal growth conditions. Using the guinea pig maternal nutrient restriction (MNR) model of FGR, ultrasound-guided, intra-placenta injections of hIGF-1 nanoparticle were performed at gestational day 30–33, and dams sacrificed 5 days later. Sub-placenta/decidua tissue was separated from placenta for further analyses. Western blot was used to analyze protein expression of ERK/AKT/mTOR signaling proteins (phospho-Erk (pERK), phospho-Akt (pAKT), raptor, rictor and deptor). qPCR was used to analyze gene expression of vascular/remodeling factors [vascular endothelial growth factor (Vegf), placenta growth factor (Pgf), platelet-derived growth factor (Pdgf)) and tight junction/adhesion proteins (claudin 5 (Cldn5), p-glycoprotein (Abcb1), occludin (Ocln) and tight junction protein 1 (Zo1)]. MNR reduced expression of pERK, PdgfB and Cldn5, and increased expression of Ocln and Zo1 in the sub-placenta/decidua. In MNR + hIGF1 nanoparticle sub-placenta/decidua, expression of PdgfB, Ocln and Zo1 was normalized, whilst pAkt, VegfB, Vegf receptor 1 and PdgfB receptor were increased compared to MNR. In contrast, hIGF-1 nanoparticle treatment of normal placentas reduced expression of pERK, raptor and increased expression of the mTOR inhibitor deptor. This was associated with reduced expression of VegfA, Plgf, and PdgfB. Here we have shown that the impact of hIGF-1 nanoparticle treatment is dependent on pregnancy environment. Under MNR/FGR, hIGF-1 nanoparticle treatment triggers increased expression of growth factors and normalization of EMT factors. However, under normal conditions, the response of the placenta is to decrease AKT/mTOR signaling and growth factor expression to achieve homeostasis.

Placental Nanoparticle-mediated IGF1 Gene Therapy Corrects Fetal Growth Restriction in a Guinea Pig Model

“…It is widely accepted that male fetuses are more susceptible to worse outcomes when affected by in utero disorders and perform more poorly in the NICU than female fetuses and neonates 38, 39 . We previously identified sexually dimorphic responses with both our MNR model and our IGF1 treatment in fetuses, recapitulating the human scenario 23, 40, 41 . While we had no directly treated female placentas, indirectly treated female placentas showed more significant IGF signaling changes in receptor, binding partner, and Igf2 mRNA levels than males, highlighting dimorphic responses based on sex.…”

“…Thus far in our nanoparticle therapy studies we have successfully delivered plasmids ex vivo and in vitro to human syncytiotrophoblast and in vivo to mouse, guinea pig, and non-human primate models and shown physiochemical properties, cellular safety, and efficiency in both mother and fetus 23, 24, 28 . We have also shown that administration of this gene therapy to the placenta in a normal pregnancy environment results in homeostatic responses within the placenta maintaining normal fetal growth and no placentomegaly 22, 28 . Previous studies using the guinea pig model of FGR from our lab have focused on short term effects of our nanoparticle-mediated IGF1 at mid-pregnancy and showed positive improvements to the placenta that could improve fetal growth, so this study employed multiple IGF1 treatments across later gestation to assess longer term impact on placental function, fetal weight and maternal environment.…”

Placental nanoparticle gene therapy normalizes gene expression changes in the fetal liver associated with fetal growth restriction in a fetal sex-specific manner

“…However, we have also shown that administration of this nanoparticle gene therapy to the placenta in a normal pregnancy environment results in down-regulation of decidual and placental mTOR signaling and growth factor gene expression in order to maintain placental homeostasis. 23…”

“…However, we have also shown that administration of this nanoparticle gene therapy to the placenta in a normal pregnancy environment results in down-regulation of decidual and placental mTOR signaling and growth factor gene expression in order to maintain placental homeostasis. 23 Animal care and transuterine, intraplacental nanoparticle administration Animal care and usage was approved by the Institutional Animal Care and Use Committees at Cincinnati Children's Hospital and Medical Center (Protocol number 2017-0065) and University of Florida (Protocol number 202011236). Detailed information on animal care, maternal nutrient restriction (MNR) implementation, and ultrasound-guided transuterine, intra-placental nanoparticle administration can be found in Wilson et al, 2022.…”

Nanoparticle-mediated delivery of placental gene therapy via uterine artery catheterization in a pregnant rhesus macaque

“…Nanoparticles offer promise as a clinically relevant vehicle for delivery of therapeutics to the placenta. We have previously demonstrated that a non-viral poly [2-hydroxypropyl] methacrylamide (HPMA) – poly(2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA) co-polymer complexed with plasmid containing human insulin-like growth factor 1 ( hIGF1 ) under the control of a placenta-specific promoter can be successfully delivered in vivo to pregnant mice 6 and guinea pigs 7, 8 , ex vivo to human placental explants 9, 10 and in vitro to human trophoblast cultures 6, 9, 10 . IGF signaling is essential to placental development and function by promoting trophoblast proliferation, syncytialization, invasion, migration and uptake of amino acids and glucose 11 .…”