transforming-growth-factor-beta and Amniotic-Band-Syndrome

The etiology of the amniotic band syndrome is unknown, and has been subject of debate since the time of Hippocrates. The most accepted theories fail to cover all the abnomalities found in affected children. During organogenesis the epithelial-mesenchymal transition process (EMTP) participates in adequate formation of different organs from three embryo layers. Altered activation of EMTP occurs when the epithelial homeostasis is disturbed, the resulting myofibroblasts are able to secrete extracellular matrix proteins and deposit them on the tissues contributing to a fibrotic phenotype. If injury occurs during organogenesis, wound healing could be exaggerated and fibrotic response could be triggered. The molecule that regulates both of these processes (EMTP and fibrosis) is the transforming growth factor β (TGFβ); indeed null animals for TGFβ isoforms show similar defects than those seen in the amniotic band syndrome. Based on documented evidence this review intends to explain how the epithelial mesenchymal transition process may contribute to the pathogenesis of amniotic band syndrome.

Topics: Amnion; Amniotic Band Syndrome; Epithelial Cells; Epithelial-Mesenchymal Transition; Female; Fibroblast Growth Factors; Fibroblasts; Fibrosis; Homeostasis; Humans; Infant, Newborn; Mutation; Organogenesis; Phenotype; Pregnancy; Signal Transduction; Transforming Growth Factor beta; Wnt Proteins

This study was undertaken to evaluate the efficacy and safety of closing the fetoscopy access site in a midgestational rabbit model by using a commercially available bioactive membrane.. Fetoscopy was performed in a total of 100 gestational sacs in 20 does at midgestation (23 days, term = 31 days). In 50 cases (group 1), the fetoscopic access port was closed with a 5-mm patch of biocompatible matrix derived from porcine small intestine containing growth factors (transforming growth factor-beta and fibroblast growth factor-beta). Fifty sacs served as positive controls (group 2) and 55 unoperated fetuses were used as negative controls (group 3). At 30 days of gestation, a second-look laparotomy was performed. Outcome parameters were fetal weight, fetal lung weight, fetal lung-to-body weight ratio, and microscopy of the plugging site.. Membrane integrity after fetoscopy was restored in 28 of the 40 (70%) of cases in group 1 versus 13 of the 32 (41%) in group 2 (P =.012). Birth weights were comparable (group 1: 30.65 +/- 5.68 g; group 2: 29.70 +/- 5.05 g; group 3: 29.52 +/- 6.25 g; NS), but fetal lung weight (group 1: 0.964 +/- 0.20 g; group 2: 0.798 +/- 0.17 g; P <.01) and fetal lung-to-body weight ratio (group 1: 0.032 +/- 0.0067; group 2: 0.027 +/- 0.0082; P <.05) were significantly higher in the study group. In group 1, cellular proliferation was significantly increased. Polymorphonuclear infiltration was observed in 19 of the 40 (48%) cases in group 1 versus 5 of the 32 (16%) cases in group 2 (P <.05). In one treated sac, a fibrous band joining the two fetal legs without constriction was present.. The use of a bioactive membrane improved fetal membrane repair rates and decreased incidence of pulmonary hypoplasia in the rabbit but increased polymorphonuclear infiltration. In one amniotic sac, a situation comparable to amniotic band syndrome was documented.

Topics: Amniotic Band Syndrome; Animals; Animals, Newborn; Biocompatible Materials; Congenital Abnormalities; Female; Fetoscopy; Fibroblast Growth Factor 2; Gestational Age; Humans; Iatrogenic Disease; Infant, Newborn; Lung; Membranes, Artificial; Neutrophil Infiltration; Rabbits; Safety; Survival Analysis; Swine; Transforming Growth Factor beta