Adsorption of fetal surfactant protein SP-B on the human amnion at term and on amniocytes incubated with fetal surfactant in vitro

1991 ◽  
Vol 3 (4) ◽  
pp. 421 ◽  
Author(s):  
GE Newman ◽  
PJ Phizackerley ◽  
Bernal A Lopez ◽  
GR Noble ◽  
AC Willis
Keyword(s):  
Monoclonal Antibody ◽  
Amniotic Fluid ◽  
Human Lung ◽  
Lung Surfactant ◽  
Surfactant Protein ◽  
Post Mortem ◽  
Human Amniotic Fluid ◽  
Human Amnion ◽  
Immunohistochemical Methods

Fetal surfactant stimulates the synthesis of prostaglandins by slices of human amnion at term and by a human amnion cell line, and these effects are partly dependent upon surfactant apoproteins. In this paper, methods are described for the purification of surfactant from human amniotic fluid and from post-mortem human lung. A procedure is described for the purification of surfactant protein SP-B from human amniotic fluid, and the sequence of 20 amino acids at the N-terminal has been determined. A monoclonal antibody generated against human lung surfactant has been shown to react with SP-B from amniotic-fluid surfactant, and the presence of SP-B on the surface of the amnion at term has been demonstrated by immunohistochemical methods. It has also been shown that SP-B from surfactant is present on the surface of amniocytes incubated with surfactant in vitro.

Prostaglandins mediate the fetal pulmonary response to intrauterine inflammation

2012 ◽  
Vol 302 (7) ◽  
pp. L664-L678 ◽  
Author(s):  
Alana J. Westover ◽  
Stuart B. Hooper ◽  
Megan J. Wallace ◽  
Timothy J. M. Moss
Keyword(s):  
Amniotic Fluid ◽  
Lung Inflammation ◽  
Lung Surfactant ◽  
Fetal Lung ◽  
Surfactant Protein ◽  
Fetal Plasma ◽  
Pulmonary Response ◽  
Surfactant Production ◽  
Prostaglandin Dehydrogenase ◽  
Prostaglandin H

Intra-amniotic (IA) lipopolysaccharide (LPS) induces intrauterine and fetal lung inflammation and increases lung surfactant and compliance in preterm sheep; however, the mechanisms are unknown. Prostaglandins (PGs) are inflammatory mediators, and PGE2 has established roles in fetal lung surfactant production. The aim of our first study was to determine PGE2 concentrations in response to IA LPS and pulmonary gene expression for PG synthetic [prostaglandin H synthase-2 (PGHS-2) and PGE synthase (PGES)] and PG-metabolizing [prostaglandin dehydrogenase (PGDH)] enzymes and PGE2 receptors. Our second study aimed to block LPS-induced increases in PGE2 with a PGHS-2 inhibitor (nimesulide) and determine lung inflammation and surfactant protein mRNA expression. Pregnant ewes received an IA saline or LPS injection at 118 days of gestation. In study 1, fetal plasma and amniotic fluid were sampled before and at 2, 4, 6, 12, and 24 h after injection and then daily, and fetuses were delivered 2 or 7 days later. Amniotic fluid PGE2 concentrations increased ( P < 0.05) 12 h and 3–6 days after LPS. Fetal lung PGHS-2 mRNA and PGES mRNA increased 2 ( P = 0.0084) and 7 ( P = 0.014) days after LPS, respectively. In study 2, maternal intravenous nimesulide or vehicle infusion began immediately before LPS or saline injection and continued until delivery 2 days later. Nimesulide inhibited LPS-induced increases in PGE2 and decreased fetal lung IL-1β and IL-8 mRNA ( P ≤ 0.002) without altering lung inflammatory cell infiltration. Nimesulide decreased surfactant protein (SP)-A ( P = 0.05), -B ( P = 0.05), and -D ( P = 0.0015) but increased SP-C mRNA ( P = 0.023). Thus PGHS-2 mediates, at least in part, fetal pulmonary responses to inflammation.

scholarly journals Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits

2021 ◽  
Vol 17 (3) ◽  
pp. e1009116
Author(s):  
Allison N. Dammann ◽  
Anna B. Chamby ◽  
Andrew J. Catomeris ◽  
Kyle M. Davidson ◽  
Hervé Tettelin ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Amniotic Fluid ◽  
Deletion Strain ◽  
Growth Defect ◽  
Wild Type ◽  
Human Amniotic Fluid ◽  
Wide Range ◽  
Pregnant Mice ◽  
Group B

Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability.

In vitro survival of Listeria monocytogenes in human amniotic fluid

1999 ◽  
Vol 202 (5) ◽  
pp. 377-382 ◽  
Author(s):  
Clelia Altieri ◽  
Giuseppe Maruotti ◽  
Costanzo Natale ◽  
Salvatore Massa
Keyword(s):  
Listeria Monocytogenes ◽  
Amniotic Fluid ◽  
Human Amniotic Fluid ◽  
In Vitro Survival

Clearance of intra-amniotic lung surfactant: uptake and utilization by the fetal rabbit lung

1997 ◽  
Vol 273 (1) ◽  
pp. L55-L63 ◽  
Author(s):  
M. Hallman ◽  
U. Lappalainen ◽  
K. Bry
Keyword(s):  
Amniotic Fluid ◽  
Lung Surfactant ◽  
Protein A ◽  
Alveolar Epithelium ◽  
Fetal Lung ◽  
Surfactant Protein ◽  
Lung Compliance ◽  
Rabbit Lung ◽  
Lower Lung ◽  
Lung Surfactant Protein

To investigate the metabolism of intra-amniotic surfactant, surfactant containing double-labeled dipalmitoylphosphatidylcholine (DPPC) was injected in amniotic fluid on days 23-27 of gestation. Within 44 h, DPPC was distributed to the gastrointestinal tract (45.9%), fetal membranes and placenta (8.2%), fetal lung (6.6%), and liver (1.9%). DPPC uptake was higher in the upper than in the lower lung lobes. The mixture of phosphatidylglycerol and DPPC increased the uptake of DPPC that was not saturable (range 15-60 mg phospholipid). There was no detectable metabolism of DPPC taken up by the fetal lung. Surfactant protein A, originating from intra-amniotic heterplogous surfactant, was detected immunohistochemically in alveolar epithelium. Intra-amniotic surfactants did not affect the expression of surfactant protein mRNAs. Intra-amniotic surfactant (1,500-2,000 mg/kg on day 25.3) improved lung compliance of ventilated 27.0-day premature rabbits less than intratracheal surfactant at birth (75-100 mg/kg). Reutilization by the alveolar epithelium of surfactant secreted to future airspaces, airways, and amniotic fluid may be a mechanism that increases intracellular surfactant pool before birth.

G-CSF and Erythropoietin Stability in Amniotic Fluid during Simulated in vitro Digestion Conditions

2002 ◽  
Vol 18 (6) ◽  
pp. 310-315 ◽  
Author(s):  
Darlene A Calhoun ◽  
Brooke E Richards ◽  
Jason A Gersting ◽  
Sandra E Sullivan ◽  
Robert D Christensen
Keyword(s):  
Amniotic Fluid ◽  
Preterm Neonate ◽  
In Vitro Digestion ◽  
Human Amniotic Fluid ◽  
Time Zero ◽  
Simulated Digestion ◽  
The Stability ◽  
Stimulating Factor ◽  
Degree Of Degradation

Objective: To determine the stability of granulocyte colony-stimulating factor (G-CSF) and erythropoietin (Epo) in human amniotic fluid and recombinant G-CSF (Neupogen) and Epo (Epogen) in simulated amniotic fluid to digestions at pH concentrations of 3.2, 4.5, and 5.8 to assess their bioavailability to the neonate. Design: A simulated amniotic fluid containing Neupogen and Epogen was subjected to in vitro conditions that mimicked preprandial and postprandial neonatal intestinal digestion. Human amniotic fluid was tested using identical digestion conditions as well as human amniotic fluid to which Epogen and Neupogen had been added. Main Outcome Measures: The percentages of G-CSF/Epo and Neupogen/Epogen remaining after 1 and 2 hours of simulated digestions were compared with those at time zero, and concentrations at 2 hours were compared with those at 1 hour and time zero. Results: In simulated amniotic fluid at pH 3.2, significant degradation of G-CSF was observed at 1 hour (p = 0.03). No differences were observed at 1 or 2 hours for either pH 4.5 (p = 0.30 and 0.11, respectively) or pH 5.8 (p = 0.20 and 0.49, respectively). Human amniotic fluid exhibited significant degradation pH 3.2 (p = 0.04) and pH 4.5 (p < 0.05) at 1 hour; no difference was noted at pH 5.8 at 1 hour (p = 0.34). When additional Neupogen was added to human amniotic fluid, significant degradation was observed at pH 3.2 (p < 0.05) and pH 4.5 (p = 0.03) at 1 hour; no difference was noted at 1 hour at pH 5.8 (p = 0.11). In simulated amniotic fluid at pH 3.2, significant degradation of Epo occurred at 1 hour (p < 0.05). There were no differences at 1 hour for pH 4.5 (p = 0.50) or pH 5.8 (p = 0.17). Human amniotic fluid exhibited significant degradation at pH 3.2 (p < 0.05) and pH 4.5 (p < 0.05) at 1 hour; no difference was noted at 1 hour at pH 5.8 (p = 0.34). When additional Epogen was added to human amniotic fluid, significant degradation was observed at pH 3.2 (p = 0.001) and pH 4.5 (p = 0.003); no difference was noted at 1 hour at pH 5.8 (p = 0.31). Conclusions: G-CSF/Epo in human amniotic fluid and Neupogen/Epogen in simulated amniotic fluid are preserved to varying degrees during simulated digestion conditions. The degree of degradation of both cytokines was time- and pH-dependent. Measurable quantities of G-CSF and Epo are biologically available when swallowed by the fetus or a preterm neonate.

scholarly journals Expression of hydrophilic surfactant proteins by mesentery cells in rat and man

1997 ◽  
Vol 328 (1) ◽  
pp. 251-256 ◽  
Author(s):  
Bernadette CHAILLEY-HEU ◽  
Sandrine RUBIO ◽  
Jean-Philippe ROUGIER ◽  
Robert DUCROC ◽  
Anne-Marie BARLIER-MUR ◽  
...  
Keyword(s):  
Lung Surfactant ◽  
Surfactant Protein ◽  
Mesothelial Cells ◽  
Surfactant Proteins ◽  
Two Dimensional ◽  
Western Blots ◽  
Mrna Species ◽  
Visceral Peritoneum ◽  
Rat Mesentery

Human peritoneal dialysis effluent (PDE) contains a phosphatidylcholine-rich compound similar to the surfactant that lines lung alveoli. This material is secreted by mesothelial cells. Lung surfactant is also characterized by four proteins essential to its function. After having long been considered as lung-specific, some of them have been found in gastric and intestinal epithelial cells. To explore further the similarity between lung and peritoneal surfactants, we investigated whether mesothelial cells also produce surfactant proteins. We used rat transparent mesentery, human visceral peritoneum biopsies and PDE. Surfactant proteins were searched for after one- and two-dimensional SDS/PAGE and Western blotting. On a one-dimensional Western blot, bands at 38 and 66 kDa in rat mesentery, and at 38 and 66 kDa in human peritoneal mesothelial cells (in vivo and in vitro) and PDE, corresponded to monomeric and dimeric forms of lung surfactant protein A (SP-A). On two-dimensional Western blots, the 32 and 38 kDa spots in mesentery and PDE localized at the acidic pH appropriate to the SP-A monomer's isoelectric point. SP-D was also identified at the same 43 kDa molecular mass as in lung. SP-B was not detected in mesenteric samples. Expression of SP mRNA species was also assessed by reverse transcriptase-PCR, which was performed with specific primers of surfactant protein cDNA sequences. With primers of SP-A and SP-D, DNA fragments of the same size were amplified in lung and mesentery, indicating the presence of SP-A and SP-D mRNA species. These fragments were labelled by appropriate probes in a Southern blot. No amplification was obtained for SP-B. These results show that mesentery cells produce SP-A and SP-D, although they are of embryonic origin (mesodermal) and are different from those of the lung and digestive tract (endodermal) that secrete these surfactants.

Interaction of transferrin saturated with iron with lung surfactant in respiratory failure

1994 ◽  
Vol 77 (2) ◽  
pp. 757-766 ◽  
Author(s):  
M. Hallman ◽  
A. Sarnesto ◽  
K. Bry
Keyword(s):  
Respiratory Failure ◽  
Surface Activity ◽  
Lung Surfactant ◽  
Protein A ◽  
Surfactant Protein ◽  
Lung Damage ◽  
Epithelial Lining ◽  
Surface Absorption ◽  
Epithelial Lining Fluid

Proteins that decrease the surface activity of surfactant accumulate in epithelial lining fluid in respiratory failure. The aim of this study was to isolate a surfactant inhibitor from the airways of rabbits in acute respiratory failure induced by bronchoalveolar lavage (BAL). This inhibitor was identified as being transferrin (TF). Unlike serum TF, TF recovered in respiratory failure was saturated with iron (Fe(3+)-TF). Fe(3+)-TF decreased the surface activity of normal surfactant in vitro, whereas iron-free TF had no effect. In the presence of H2O2 and a reducing agent, Fe(+3)-TF inactivated the surfactant complex: the surface absorption rate was decreased, immunoreactive surfactant protein A was decreased, and malondialdehyde was formed. The acute effects of Fe(3+)-TF and iron-free TF applied to the airways were studied in animal models. In respiratory failure induced by BAL, Fe(3+)-TF deteriorated respiratory failure, whereas iron-free TF had no effect. In respiratory failure induced by hyperoxia for 48 h, administration of iron-free TF ameliorated the respiratory failure and improved the surface activity in BAL. We propose that Fe(3+)-TF accumulating in epithelial lining fluid during lung damage contributes to surfactant inhibition and promotes the formation of free radicals that inactivate the surfactant system.

Fluorometric procedure for determining "lamellar body" phospholipids in the particulate fraction of amniotic fluid after filtration.

1983 ◽  
Vol 29 (2) ◽  
pp. 362-365 ◽  
Author(s):  
J Egberts ◽  
W Soederhuizen ◽  
D O Gebhardt
Keyword(s):  
Amniotic Fluid ◽  
Lung Surfactant ◽  
Lamellar Body ◽  
Fetal Lung ◽  
Human Amniotic Fluid ◽  
Wide Range ◽  
Before And After ◽  
The Difference ◽  
Filtration Step ◽  
Good Agreement

Abstract A rapid (30-min) semiautomated continuous-flow procedure is described for use in assessing the phospholipids of the particulate ("lamellar body") fraction of human amniotic fluid. The method is based on measuring the difference in fluorescence of 1,6,-diphenyl-1,3,5-hexatriene added to amniotic fluid before and after micropore filtration. The filtration step removes "lamellar body" particles, which are considered to contain the fetal lung surfactant. The phospholipid values for the filtered particles are independent of background fluorescence, which increases when amniotic fluid is contaminated by bilirubin pigments or blood components. Over a wide range (3-150 mumols/L) the fluorescence increases linearly with the phospholipid concentration of the amniotic fluid. There is a good agreement between the value for particulate "lamellar body" phospholipid, the ratio of the "lamellar body" phospholipids to total amniotic fluid phospholipids, and the lecithin/sphingomyelin ratio.

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