Patrizia Doi

Autophagy in term normal human placentas

Autophagy is an inducible catabolic process that responds to environment and is essential for cell survival during stress, starvation and hypoxia. Its function in the human placenta it is not yet understood. We collected 14 placentas: 7 at vaginal delivery and 7 at elective caesarean section after uneventful term pregnancies. The presence of autophagy was assessed in different placental areas by immunoblotting, immunohistochemistry and electron microscopy. We found that autophagy is significantly higher in placentas obtained from cesarean section than in those from vaginal delivery. Moreover there is a significant inverse relationship between autophagy and umbilical arterial glucose concentration.

SNAT2 expression and regulation in human growth-restricted placentas

Background:Amino acid placental delivery is reduced in human intrauterine growth–restricted (IUGR) fetuses, and the activity of placental amino transporters has been consistently shown to be decreased in in vitro studies. We hypothesized lower placental expression and localization of sodium-coupled neutral amino acid transporter 2 (SNAT2 (also known as SLC38A2)), altered levels of intron-1 methylation, and altered distribution of single-nucleotide polymorphisms in human IUGR vs. normal pregnancies.Methods:We studied 88 IUGR and 84 control placentas from singleton pregnancies at elective caesarean section. SNAT2 expression was investigated by real-time PCR and immunohistochemistry. Intron-1 methylation levels were analyzed by pyrosequencing, and single-nucleotide polymorphism distribution was analyzed by allelic discrimination.Results:mRNA levels were significantly decreased in IUGR placentas with reduced umbilical blood flows. Syncytiotrophoblast immunostaining was lower in IUGR placentas than in control placentas. Methylation levels were steadily low in both IUGR and control placentas. SNP genotype and allele frequencies did not differ between the two groups.Conclusion:This is the first study investigating SNAT2 expression and regulation mechanisms in human IUGR placentas. We confirm previous results obtained in rats and cell cultures that support the fundamental role of SNAT2 in fetal growth and well-being, as well as a possible role of oxygen levels in regulating SNAT2 expression, indicating the relevance of hypoxia in IUGR.

Autophagy in placentas from acidotic newborns: an immunohistochemical study of LC3 expression.

Autophagy is an inducible catabolic process activated during compromised conditions, such as hypoxia. Neonatal encephalopathy (NE) is a syndrome of disturbed neurological function. No absolute prognostic indicators are available at birth to identify neonates at high risk to develop NE. Immunohistochemical staining with LC3 antibody was performed on 40 placentas from uneventful term singleton pregnancies with umbilical artery pH ≤ 7.00 at birth; semi-quantitative analysis was carried-out to estimate autophagy level. 6/40 (15%) neonates developed NE. Placentas from newborns with NE exhibited a higher LC3 expression. Autophagy protein expression in placentas with severe acidosis is a potential marker for poor outcome.

Autophagy and Human Parturition: Evaluation of LC3 Expression in Placenta from Spontaneous or Medically Induced Onset of Labor

Induction of labor is one of the most used procedures in obstetrics, performed to achieve vaginal delivery through cervical ripening and stimulation of uterine contractions. We investigated the impact of induction of labor upon placental autophagy, a catabolic pathway activated in response to alteration of the physiological intracellular conditions. We collected 28 singleton placentas at the time of uncomplicated term vaginal delivery (7 spontaneous onset of labor, 21 induced labor). Autophagy was evaluated by immunohistochemistry, immunofluorescence, and immunoblotting. No significant difference in the autophagy expression was found between spontaneous or induced onset of labor. We found an inverse relationship between autophagy expression and the maternal prepregnancy body mass index, irrespective of the mode of labor onset. This result could be related to the nutritional maternal habits before and throughout pregnancy rather than rapid metabolic changes during labor.

Chromosome 7 monosomy and deletions in myeloproliferative diseases

We studied deletion and monosomy of chromosome 7 in 150 patients with myeloproliferative diseases. We found 8/150 patients with monosomy 7 by cytogenetics and 4/150 with deletions of the long arm of chromosome 7 by restriction fragment length polymorphism (RFLP) analysis performed with Southern and polymerase chain reaction. To overcome limitation of RFLP analysis, we restricted loss of heterozygosity study with microsatellites to 45 patients, observing deletion 7q31.1 in 7/45 patients. In all patients with molecular alterations the deletion was observed only in myeloid cells, while the monosomy was detected in both myeloid precursor and lymphocytes. This finding suggests a CD34-totipotent stem cell origin for the monosomy and a colony forming unit - granulocyte, erythrocyte, monocyte, megakaryocytes (CFU-GEMM) stem cell origin for the deletions.

Autophagy in Normal and Abnormal Early Human Pregnancies

Autophagy is an inducible catabolic process by which cells degrade and recycle materials to survive stress, starvation, and hypoxia. The aim of this study was to evaluate autophagy at the fetal–maternal interface, to assess autophagy involvement during the early phase of human gestation, and to explore autophagic modification in case of early abnormal pregnancy outcome. Specimens were collected from first-trimester normal gestations undergoing legal termination of pregnancy and first-trimester sporadic spontaneous miscarriages. Autophagy was studied in villous and decidual samples by transmission electron microscopy, immunohistochemistry, immunofluorescence, and Western blotting. Autophagy markers were found in cytotrophoblast, syncytiotrophoblast, extravillous trophoblast, and decidual stromal cells. Autophagy is physiologically involved in early normal gestation. Compared with normal pregnancy, spontaneous miscarriage presents an increase in autophagy expression in villous specimens due to an increment in concentration of autophagic vacuole in syncytiotrophoblast, suggesting a cytoprotective mechanism of the cells to respond to microenvironmental challenge.

Inflammation modulates LC3 expression in human preterm delivery

Abstract Objective: Autophagy is an inducible intracellular process acting under stressor conditions, such as infections, inflammation and hypoxia. The aim of the present study was to analyze autophagy expression in preterm delivered human placenta. Methods: Autophagy marker LC3 was analyzed in 25 consecutive human placentas delivered before 34 weeks of gestation, analyzed by immunohistochemistry, immunofluorescence and quantitative real-time PCR, according to the histologic classification of preterm delivery (PTD) (cases with or without placental inflammatory lesions). Results: LC3 expression was observed both in cases with and without inflammatory lesions. In cases with histological inflammation, strong immunoreactivity for LC3 autophagic marker was observed in the inflammatory cell infiltration composed by neutrophils. In all PTD cases, trophoblastic cells in chorion laeve express LC3, with variable staining intensity: a significant reduction of LC3 expression was observed in chorion laeve of PTD with histological inflammation compared to PTD without inflammatory lesions. Moreover, the decrement of LC3 staining was observed to be associated to the increasing severity of the histological signs of fetal inflammatory response. Conclusions: Our data show that the expression of LC3 varies depending on different histological features, indicating an interesting and possibly clinically relevant relation between autophagy expression levels and the inflammatory status.

Cell death and cell proliferation in human spina bifida

BACKGROUND Spina bifida is a multifactorial congenital malformation of the central nervous system. The aim of this study was to ascertain the relevance of cell death/proliferation balance in human spina bifida and to assess autophagy distribution and levels during embryo-fetal development in neural tissue. METHODS Five human cases with myelomeningocoele were compared with 10 healthy human controls and LC3 protein expression was also analyzed in mouse embryos. Cell death was evaluated using TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling) assay; cell proliferation was studied by counting Ki67-positive cells, and autophagy was assessed by observing the presence of LC3 punctuate dots. RESULTS Comparing human cases and controls (13 to 21 weeks of gestation), we observed a significant increase in TUNEL-positive cells in human spina bifida associated with a significantly decreased proliferation rate, indicating an alteration of the physiological cell rate homeostasis. LC3 distribution was found to be spatiotemporally regulated in both human and murine embryo-fetuses: in early pregnancy a diffuse and ubiquitous LC3 signal was detected. After neural tube closure, an intense LC3-positive signal, normally associated to extra energy requirement, was confined to the Lissauers tract, the dorsolateral spinal zone containing centrally projecting axons from dorsal root ganglia, at any medullar levels. LC3 signal disappeared from 12 weeks of gestation. CONCLUSION In conclusion, this study confirms the fundamental role of cell death/proliferation balance during central nervous system development and reports the changing expression of LC3 protein in mouse and human neural tube. Birth Defects Research (Part A) 106:104-113, 2016.

Activation of Protein C in Human Trophoblasts in Culture and Downregulation of Trophoblast Endothelial Protein C Receptor by TNF-α

In mice, trophoblasts are equipped with a potent anticoagulant mechanism, the protein C pathway. In human placenta, no functional studies of the protein C pathway are available. Human first-trimester trophoblasts (CK++ HLA-G+/− Vim− ) were isolated and kept in culture for a maximum of 48 hours. Activation of protein C on trophoblasts was at least as efficient as in endothelial cells (4.43 × 10 − 7 nmol/L/min/cell). Endothelial protein C receptor (EPCR) was expressed in syncytiotrophoblasts and extravillous trophoblasts. Downregulation of the messenger RNA of trophoblast EPCR occurred when trophoblasts were challenged with tumor necrosis factor α, and it could be prevented by unfractionated heparin but not by low-molecular-weight heparin at therapeutic doses. In conclusion, there is a functional protein C pathway on human first-trimester trophoblasts which can be modulated by inflammation. This finding has implications for the pathogenesis and prevention of placenta-mediated obstetric complications.

An imbalance of COX level is not related to placental abruption

Aims Muscularised basal plate arteries (MA) or chorioamnionitis (CA) are often present in placental abruption. The aim of this study was to evaluate the placental expression of COX 1 and COX 2 in cases of placental abruption with MA or CA hypothesising that an imbalance in COX placental expression might be implicated in its pathogenesis. Methods COX 1 and COX 2 placental immunostaining was analysed in 16 placentas with abruption (nine with MA, seven with CA), in 26 normal placentas and in 10 gestational age-matched MA or CA cases without abruption. Results COX 1 and COX 2 protein expression was observed in all cases, both in placental abruption and in normal placentas. No differences in distribution of immunoreactivity were observed either between cases and controls or between MA and CA. The mean COX 1 ratio between COX-positive cells and all stromal cells was significantly lower in placental abruption with MA (0.14±0.05) when compared with cases with CA (0.35±0.06) and normal placenta (0.23±0.02; p<0.001). The mean COX 2 ratio was lower in placental abruption with MA than in normal placenta (0.09±0.06 vs 0.18±0.05: p<0.001). In contrast, no difference in COX 1 and COX 2 ratio was observed between MA cases with or without abruption and between CA cases with or without abruption. Conclusions It is hypothesised that an imbalance of normal COX level may be present in cases with MA and CA but it is not related to placental abruption.