The cholinergic response is increased in isolated ileum from gastroschisis rat model

Development and Validation of a Minimally Invasive Transuterine Experimental Model of Gastroschisis

INTRODUCTION

Perinatal management of gastroschisis remains a subject of substantial research. Current models, including teratogenic, genetic, and surgical approaches, often fail to accurately replicate gastroschisis, exhibiting limitations such as inaccurate phenotyping, low success rates, high mortality, lack of scientific validation, and significant technical challenges. Refined disease models are essential for improving the understanding of GS. This study seeks to develop and validate a minimally invasive transuterine experimental model of GS that overcomes these existing constraints to advance gastroschisis research.

METHODS

A gastroschisis model was surgically created in rat fetuses at E17 (n = 51 fetuses from n = 13 dams). Intestines were harvested at term and divided into herniated gastroschisis (GS-H), intra-abdominal gastroschisis (GS-I), and control (Co) groups. Morphometric analysis, histopathological examination, immunohistochemistry for interstitial cells of Cajal (ICC), double immunofluorescence for ICC and mast cells, TUNEL assay for apoptotic cells, and multiplex cytokine assay were performed to assess intestinal architecture, inflammation, ICC network, apoptosis, and cytokine levels across studied groups.

RESULTS

Histology from GS intestines revealed subchronic inflammation, peel formation, and architectural disruption. Herniated intestines exhibited a significantly increased weight/length ratio and thicker outer layers (p < 0.001) compared with control intestines. Herniated intestines had elevated inflammatory cytokine levels (GS-H vs GS-I and Co, p < 0.05 for G-CSF, GM-CSF, IL-12p70, IL-1beta) and increased apoptotic activity.

CONCLUSIONS

We developed and validated a new surgical model of GS that offers improved survival and feasibility. The key morphological changes and molecular markers observed in this experimental model resemble human gastroschisis.

Factors associated with cholestasis in newborns with gastroschisis

OBJECTIVE

To describe the incidence and to analyze risk factors associated with cholestasis in neonates with gastroschisis.

METHODS

This is a retrospective cohort study in a tertiary single center analyzing 181 newborns with gastroschisis between 2009 and 2020. The following risk factors associated with cholestasis were analyzed: gestational age, birth weight, type of gastroschisis, silo closure or immediate closure, days of parenteral nutrition, type of lipid emulsion, days of fasting, days to reach a full diet, days with central venous catheter, presence of infections, and outcomes.

RESULTS

Among the 176 patients evaluated, 41 (23.3%) evolved with cholestasis. In the univariate analysis, low birth weight (p=0.023), prematurity (p<0.001), lipid emulsion with medium-chain triglycerides and long-chain triglycerides (p=0.001) and death (p<0.001) were associated with cholestasis. In the multivariate analysis, patients who received lipid emulsion with fish oil instead of medium chain triglycerides/long chain triglycerides (MCT/LCT) emulsion had a lower risk of cholestasis.

CONCLUSIONS

Our study shows that lipid emulsion with fish oil is associated with a lower risk of cholestasis in neonates with gastroschisis. However, this is a retrospective study and a prospective study should be performed to confirm the results.

The role of gut-liver axis in the restriction of intrauterine growth in a model of experimental gastroschisis

PURPOSE

To evaluate the intrauterine growth restriction (IUGR) by the expression of IR-β, IRS-1, IRS-2, IGF-IRβ and Ikappaβ in experimental model of gastroschisis.

METHODS

Pregnant rats at 18.5 days of gestation were submitted to surgery to create experimental fetal gastroschisis (term = 22 days) were divided in three groups: gastroschisis (G), control (C) and sham (S). Fetuses were evaluated for body weight (BW), intestinal (IW), liver (LW) and their relations IW/BW and LW/BW. IR-β and IGF-IRβ receptors, IRS-1 and IRS-2 substrates and Ikappaβ protein were analyzed by western blotting.

RESULTS

BW was lower in G, the IW and IW / BW were greater than C and S (p<0.05) groups. The liver showed no differences between groups. In fetuses with gastroschisis, compared with control fetuses, the expression of IGF-IRβ (p<0.001) and Ikappaβ (p<0.001) increased in the liver and intestine, as well as IR-β (p<0.001) which decreased in both. In contrast to the intestine, IRS-1 (p<0.001) increased in the liver and IRS-2 decreased (p<0.01).

CONCLUSION

The axis of the intestine liver has an important role in inflammation, with consequent changes in the metabolic pathway of glucose can contribute to the IUGR in fetuses with gastroschisis.

Gastric contractility in experimental gastroschisis

BACKGROUND/PURPOSE

The mechanism of fetal gastric dilation in gastroschisis is controversial. This study was designed to characterize changes in the contractile profile of strips of stomach from rats following experimental gastroschisis.

METHODS

Pregnant Wistar rats were operated on day 18.5. Fetuses were divided into three groups: gastroschisis (G), sham (S), and control (C). On day 21.5, gastric fundus and antrum strips were obtained and suspended to a force transducer connected to a digital data acquisition system. They were submitted to increasing concentrations of carbachol (CCh) and weighed at the end of each procedure. Frequency and amplitude of each contraction were evaluated.

RESULTS

Under basal conditions, spontaneous oscillatory contractions of antrum and fundus strips of G, S, and C were similar (P>0.05; ANOVA). However, cumulative concentrations of CCh (0.01-100 μM) produced different effects in all groups and were characterized by a significant increase in amplitude and frequency of spontaneous contractions in antral smooth muscle and a sustained increase in tonus in fundic strips. Upon analysis, no significant difference in frequency or amplitude was noted in antral tissues comparing C to G and to S (P>0.05). No significant contractility difference was noted in fundic smooth muscle (comparing all groups, P>0.05), with the CCh-induced curve following a typical sigmoidal format, dependent on increasing concentrations (P<0.001).

CONCLUSIONS

Gastric contractile responses to CCh are preserved in experimental gastroschisis. These results do not support the theory that gastric dilation occurs secondary to intestinal inflammation alone.