Uso de membrana amniótica como cobertura temporal en pacientes pediátricos con quemaduras / Use of amniotic membrane as temporary coverage in pediatric patients with burn

Introducción: Los niños con quemaduras tienen un manejo complejo por lo cual el uso de la membrana amniótica como una cobertura temporal es un método válido para su implementación. Objetivos: Demostrar el uso de la membrana amniótica como cobertura temporal en pacientes pediátricos con quemaduras de segundo grado superficiales y profundas internados en el Centro Nacional de Quemaduras y Cirugías Reconstructivas (CENQUER), en julio y diciembre del 2021. Materiales y métodos: Estudio descriptivo de tipo retrospectivo mediante la revisión de casos clínicos-quirúrgicos de los pacientes pediátricos que ingresaron por diagnóstico de quemadura de segundo grado superficial y profundo en el CENQUER, durante el período comprendido entre julio y diciembre del 2021, donde se aplicó́ membrana amniótica humana. Resultados: Población de 14 pacientes, 11 provenían del departamento central y 3 del interior del país, con un promedio de 13% (R: 3%-25,5%) de superficie corporal quemada (SCQ) todos con quemaduras en promedio 7% tipo AB y 6% tipo ABB, 7 ingresaron con una gravedad moderada, 4 graves y 3 leves; 7 del sexo masculino y 7 del femenino , con un rango de edades entre 8 meses y 11 años cuya media fue de 4 años y una mediana de 7 años, con respecto al peso un promedio de 18 kg al ingreso % (R: 9-35 kg), las causas de las lesiones fueron 12 por escaldadura por agua caliente (85 %) y 2 por escaldadura con comida; 10 pacientes presentaron internación en sala y en la Unidad de terapia intensiva Pediátrica (UTIP) 4 pacientes, el promedio de tiempo transcurrido desde la quemadura a la consulta fueron de 7 hs (R: 1-48 hs), las regiones anatómicas que se cubrieron fueron: 4 pacientes en miembros superiores y tórax anterior (28 %), 2 exclusivamente en tórax anterior (16 %), 4 solo en miembros superiores (28 %), 4 en miembros inferiores (28 %), a los que se les colocó amnios por única ocasión en 10 pacientes a las 24 hs de la internación y en 4 pacientes a las 48 hs de internación, se utilizó antobioticoterapia parenteral en 3 pacientes y 11 pacientes no necesitaron antibioticoterapia parenteral, no se presentaron complicaciones en ninguno de los pacientes y tuvieron un promedio de internación de 8 días (R: 3- 16 días). Conclusión: El uso de membrana amniótica humana en pacientes quemados son favorables para los pacientes pediátricos; como demuestra en el estudio el menor uso de antibioticoterapia parenteral por la cobertura rápida de las heridas causadas por las quemaduras y el menor número de días de internación.

Introduction: Children with burns have a complex management for which the use of the amniotic membrane as a temporary cover is a valid method for its implementation. Objectives: Demonstrate the use of the amniotic membrane as temporary coverage in pediatric patients with superficial and deep second-degree burns admitted to the National Center for Burns and Reconstructive Surgery (CENQUER), in July and December 2021. Materials and methods: Descriptive retrospective study through the review of clinical-surgical cases of pediatric patients who were admitted due to a diagnosis of superficial and deep second-degree burns in the CENQUER, during the period between July and December 2021, where human amniotic membrane was applied. Results: Population of 14 patients, 11 came from the central department and 3 from the interior of the country, with an average of 13% (R: 3%-25.5%) of burned body surface area (SCQ), all with average 7% AB type burns. and 6% type ABB, 7 admitted with moderate severity, 4 severe and 3 mild; 7 males and 7 females, with an age range between 8 months and 11 years, whose average was 4 years and a median of 7 years, with respect to weight an average of 18 kg at admission % (R: 9- 35 kg), the causes of the injuries were 12 due to scalding due to hot water (85%) and 2 due to scalding with food; 10 patients were hospitalized in the ward and in the Pediatric Intensive Care Unit (PICU) 4 patients, the average time elapsed from the burn to the consultation was 7 hours (R: 1-48 hours), the anatomical regions that were covered were: 4 patients in the upper limbs and anterior thorax (28%), 2 exclusively in the anterior thorax (16%), 4 only in the upper limbs (28%), 4 in the lower limbs (28%), who received amnios for a single occasion in 10 patients at 24 hours of hospitalization and in 4 patients at 48 hours of hospitalization, parenteral antibiotic therapy was used in 3 patients and 11 patients did not need parenteral antibiotic therapy, there were no complications in any of the patients and they had an average hospital stay of 8 days (R: 3-16 days). Conclusion: The use of human amniotic membrane in burn patients is favorable for pediatric patients; As shown in the study, the lower use of parenteral antibiotic therapy due to the rapid coverage of wounds caused by burns and the lower number of days of hospitalization.

Modifications in the Intestinal Functionality, Morphology and Microbiome Following Intra-Amniotic Administration (Gallus gallus) of Grape (Vitis vinifera) Stilbenes (Resveratrol and Pterostilbene).

This efficacy trial evaluated the effects of two polyphenolic stilbenes, resveratrol and pterostilbene, mostly found in grapes, on the brush border membrane functionality, morphology and gut microbiome. This study applied the validated Gallus gallus intra-amniotic approach to investigate the effects of stilbene administration versus the controls. Three treatment groups (5% resveratrol; 5% pterostilbene; and synergistic: 4.75% resveratrol and 0.25% pterostilbene) and three controls (18 MΩ H2O; no injection; 5% inulin) were employed. We observed beneficial morphological changes, specifically an increase in the villus length, diameter, depth of crypts and goblet cell diameter in the pterostilbene and synergistic groups, with concomitant increases in the serum iron and zinc concentrations. Further, the alterations in gene expression of the mineral metabolism proteins and pro-inflammatory cytokines indicate a potential improvement in gut health and mineral bioavailability. The cecal microbiota was analyzed using 16S rRNA sequencing. A lower α-diversity was observed in the synergistic group compared with the other treatment groups. However, beneficial compositional and functional alterations in the gut microbiome were detected. Several key microbial metabolic pathways were differentially enriched in the pterostilbene treatment group. These observations demonstrate a significant bacterial-host interaction that contributed to enhancements in intestinal functionality, morphology and physiological status. Our data demonstrate a novel understanding of the nutritional benefits of dietary stilbenes and their effects on intestinal functionality, morphology and gut microbiota in vivo.

Cigarette Smoke Condensate Exposure Induces Receptor for Advanced Glycation End-Products (RAGE)-Dependent Sterile Inflammation in Amniotic Epithelial Cells.

Maternal smoking is a risk factor of preterm prelabor rupture of the fetal membranes (pPROM), which is responsible for 30% of preterm births worldwide. Cigarettes induce oxidative stress and inflammation, mechanisms both implicated in fetal membranes (FM) weakening. We hypothesized that the receptor for advanced glycation end-products (RAGE) and its ligands can result in cigarette-dependent inflammation. FM explants and amniotic epithelial cells (AECs) were treated with cigarette smoke condensate (CSC), combined or not with RAGE antagonist peptide (RAP), an inhibitor of RAGE. Cell suffering was evaluated by measuring lactate dehydrogenase (LDH) medium-release. Extracellular HMGB1 (a RAGE ligand) release by amnion and choriodecidua explants were checked by western blot. NF-κB pathway induction was determined by a luciferase gene reporter assay, and inflammation was evaluated by cytokine RT-qPCR and protein quantification. Gelatinase activity was assessed using a specific assay. CSC induced cell suffering and HMGB1 secretion only in the amnion, which is directly associated with a RAGE-dependent response. CSC also affected AECs by inducing inflammation (cytokine release and NFκB activation) and gelatinase activity through RAGE engagement, which was linked to an increase in extracellular matrix degradation. This RAGE dependent CSC-induced inflammation associated with an increase of gelatinase activity could explain a pathological FM weakening directly linked to pPROM.

The effects of cold, dry and heated, humidified amniotic insufflation on sheep fetal membranes.

INTRODUCTION: Uterine distension with pressurised carbon dioxide (CO2) (amniotic insufflation) is used clinically to improve visibility during keyhole fetal surgery. However, there are concerns that amniotic insufflation with unconditioned (cold, dry) CO2 damages the fetal membranes which leads to post-operative preterm prelabour rupture of membranes (iatrogenic PPROM). We assessed whether heating and humidifying the insufflated CO2 could reduce fetal membrane damage in sheep. METHODS: Thirteen pregnant ewes at 103-106 days gestation underwent amniotic insufflation with cold, dry (22 °C, 0-5% humidity, n = 6) or heated, humidified (40 °C, 95-100% humidity, n = 7) CO2 at 15 mmHg for 180 min. Twelve non-insufflated amniotic sacs acted as controls. Fetal membrane sections were collected after insufflation and analysed for molecular and histological markers of cell damage (caspase 3 and high mobility group box 1 [HMGB1]), inflammation (interleukin 1-alpha [IL1-alpha], IL8 and vascular cell adhesion molecule [VCAM]) and collagen weakening (matrix metalloprotease 9 [MMP9]). RESULTS: Exposure to cold, dry CO2 increased mRNA levels of caspase 3, HMGB1, IL1-alpha, IL8, VCAM and MMP9 and increased amniotic epithelial caspase 3 and HMGB1 cell counts relative to controls. Exposure to heated, humidified CO2 also increased IL8 levels relative to controls however, HMGB1, IL1-alpha and VCAM mRNA levels and amniotic epithelial HMGB1 cell counts were significantly lower than the cold, dry group. DISCUSSION: Amniotic insufflation with cold, dry CO2 damaged the amniotic epithelium and induced fetal membrane inflammation. Heated, humidified insufflation partially mitigated this damage and inflammation in sheep and may prove an important step in reducing the risk of iatrogenic PPROM following keyhole fetal surgery.

Impact of Progesterone on Molecular Mechanisms of Preterm Premature Rupture of Membranes.

The role and mechanisms of progesterone in preterm premature rupture of membranes (PPROM) remains unclear. This study aims to investigate the molecular mechanisms of action of progesterone in pre-labor full-term fetal amniotic membrane cells with and without stimulation by microbial, pro-inflammatory, or thrombogenic agents. Fetal amniotic membranes were collected from 30 women with a normal singleton pregnancy undergoing elective cesarean section at term prior to the onset of labor. The human amniotic epithelial cells isolated were pretreated with and without medroxyprogesterone acetate for 24 h. Then, cells were treated with and without TLR/NLR agonists, pro-inflammatory cytokines, or thrombin for 48 h. Semi-quantitative RT-PCR, Western blot, and caspase-3 activity measurement were performed. Progesterone stimulation decreased the expression of TLR2, TLR5, and Nod2 genes (alone and/or in combination with TLR/NLR agonists) and decreased the expression of IL-1ß and IL-8 genes increased by stimulation with specific agonists for TLR2, TLR4, TLR5, Nod1, and Nod2. Moreover, progesterone decreased thrombin-induced IL-8 gene expression. Progesterone also decreased expression of Bax and Bid proteins (pro-apoptotic factors) increased by stimulation with pro-inflammatory cytokines (TNF-α, NGAL, IL-18, and IL-1ß) and thrombin. Progesterone stimulation alone as well as co-stimulation with TNF-α, NGAL, IL-18, IL-1ß, or thrombin with progesterone either increased, decreased, or did not change the expression of Bcl-2, Bcl-XL, or XIAP genes (anti-apoptotic factors). These data suggest progesterone plays protective roles against PPROM through anti-microbial, anti-inflammatory, and anti-thrombogenic actions on human-term fetal amniotic membrane cells. Progesterone alters pro-inflammatory cytokine- and thrombin-induced apoptosis by controlling the expression of pro-apoptotic and anti-apoptotic factors.

Evaluation of pigment epithelium-derived factor concentration in equine amniotic membrane homogenate and its in-vitro vascular endothelial growth factor inhibition effect in tears of dogs with vascularized ulcerative keratitis.

Background: Corneal neovascularization can result from many pathological processes affecting the ocular surface leading to disturbances and opacifications that reduce corneal clarity and may impact vision. In veterinary medicine, the use of topical corticosteroid is contraindicated in the presence of ulcerative keratitis, and there is sparse research regarding safe medical alternatives to inhibit corneal neovascularization in dogs to improve visual outcome. Aim: To investigate the pigment epithelium-derived factor (PEDF) concentration in equine amniotic membrane homogenate (EAMH) and its in-vitro vascular endothelial growth factor (VEGF) inhibition in tears of dogs with vascularized ulcerative keratitis. Methods: Homogenates from 10 equine amniotic membranes (AM) were analyzed by sandwich enzyme-linked immunosorbent assay (ELISA) for quantification of equine PEDF and VEGF. Forty tear samples were collected from both eyes of dogs diagnosed with vascularized ulcerative keratitis, and 50 samples from healthy dogs. Samples from affected eyes were allocated to G1 - affected undiluted tears; G2 - affected tears diluted with phosphate-buffer solution; G3 - affected tears treated with low-concentrated EAMH; and G4 - affected tears treated with high-concentrated EAMH. Tears from the unaffected contralateral eyes were composed in G5, while G6 was composed by tears from healthy dogs (control). The presence and levels of VEGF were evaluated in all groups by Western blot and ELISA. Results: The PEDF:VEGF ratio in EAMH was 110:1. An increase in VEGF levels was observed in tears from eyes with vascularized corneal ulcers (G1) as well as in contralateral tears (G5), compared to normal dogs (G6). High-concentrated EAMH provided a greater decrease in VEGF levels in-vitro compared to low-concentrated EAMH. Conclusion: EAMHs exhibited high concentrations of PEDF in comparison to VEGF and were able to partially decrease VEGF levels in tears of dogs with vascularized ulcers, in-vitro. Our results suggest that VEGF concentration is elevated in tears of dogs with active vascularized ulcerative keratitis in both affected and contralateral eyes compared to that of healthy dogs.

Collagen type I promotes osteogenic differentiation of amniotic membrane-derived mesenchymal stromal cells in basal and induction media.

Collagen has been widely shown to promote osteogenesis of bone marrow mesenchymal stromal cells (BM-MSCs). Due to the invasive procedure of obtaining BM-MSCs, MSCs from other tissues have emerged as a promising alternative for regenerative therapy. MSCs originated from different sources, exhibiting different differentiation potentials. Therefore, the applicability of collagen type I (COL), combining with amniotic membrane (AM)-MSCs was examined through proliferation and differentiation assays together with the expression of surface markers and genes associated with stemness and differentiation under basal or induction conditions. No increase in cell growth was observed because AM-MSCs might be directed toward spontaneous osteogenesis. This was evidenced by the calcium deposition and elevated expression of osteogenic genes when AM-MSCs were cultured in collagen plate with basal media. Under the osteogenic condition, reciprocal expression of OCN and CEBPA suggested a shift toward adipogenesis. Surprisingly, adipogenic genes were not elevated upon adipogenic induction, although oil droplets deposition was observed. In conclusion, our findings demonstrated that collagen causes spontaneous osteogenesis in AM-MSCs. However, the presence of exogenous inductors could shift the direction of adipo-osteogenic gene regulatory network modulated by collagen.

Anti-inflammatory effects of dexmedetomidine on human amnion-derived WISH cells.

Background: To maintain the normal pregnancy, suppression of inflammatory signaling pathway is a crucial physiologic response. Dexmedetomidine has been used for labor analgesia or supplement of inadequate regional analgesia during delivery. And it has been reported that dexmedetomidine has an anti-inflammatory effect. In this study, we examined the influence of dexmedetomidine on the expression of cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2) and inflammatory cytokines in lipopolysaccharide (LPS)-stimulated human amnion-derived WISH cells. In addition, we evaluated the association of mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) pathway in anti-inflammatory effect of dexmedetomidine. Methods: Human amnion-derived WISH cells were pretreated with various concentrations of dexmedetomidine (0.001-1 µg/ml) for 1 h and after then treated with LPS (1 µg/ml) for 24 h. MTT assay was conducted to evaluate the cytotoxicity. Nitric oxide (NO) production was analyzed using Griess-reaction microassay. RT-PCR was performed for analysis of mRNA expressions of COX-2, PGE2, tumor necrosis factor (TNF)-α and interlukin (IL)-1ß. Protein expressions of COX-2, PGE2, p38 and NF-κB were analyzed by western blotting. Results: LPS and dexmedetomidine had no cytotoxic effect on WISH cells. There was no difference in NO production after dexmedetomidine pretreatment. The mRNA and protein expressions of COX-2 and PGE2 were decreased by dexmedetomidine pretreatment in LPS-treated WISH cells. Dexmedetomidine also attenuated the LPS-induced mRNA expression of TNF-α and IL-1ß. The activation of p38 and NF-κB was suppressed by dexmedetomidine pretreatment in LPS-treated WISH cells. Conclusion: We demonstrated that dexmedetomidine pretreatment suppressed the expressions of inflammatory mediators increased by LPS. In addition, this study suggests that anti-inflammatory effect of dexmedetomidine on WISH cells was mediated by the inhibitions of p38 and NF-κB activation.

Differential Response of Gestational Tissues to TLR3 Viral Priming Prior to Exposure to Bacterial TLR2 and TLR2/6 Agonists.

Background: Infection/inflammation is an important causal factor in spontaneous preterm birth (sPTB). Most mechanistic studies have concentrated on the role of bacteria, with limited focus on the role of viruses in sPTB. Murine studies support a potential multi-pathogen aetiology in which a double or sequential hit of both viral and bacterial pathogens leads to a higher risk preterm labour. This study aimed to determine the effect of viral priming on bacterial induced inflammation in human in vitro models of ascending and haematogenous infection. Methods: Vaginal epithelial cells, and primary amnion epithelial cells and myocytes were used to represent cell targets of ascending infection while interactions between peripheral blood mononuclear cells (PBMCs) and placental explants were used to model systemic infection. To model the effect of viral priming upon the subsequent response to bacterial stimuli, each cell type was stimulated first with a TLR3 viral agonist, and then with either a TLR2 or TLR2/6 agonist, and responses compared to those of each agonist alone. Immunoblotting was used to detect cellular NF-κB, AP-1, and IRF-3 activation. Cellular TLR3, TLR2, and TLR6 mRNA was quantified by RT-qPCR. Immunoassays were used to measure supernatant cytokine, chemokine and PGE2 concentrations. Results: TLR3 ("viral") priming prior to TLR2/6 agonist ("bacterial") exposure augmented the pro-inflammatory, pro-labour response in VECs, AECs, myocytes and PBMCs when compared to the effects of agonists alone. In contrast, enhanced anti-inflammatory cytokine production (IL-10) was observed in placental explants. Culturing placental explants in conditioned media derived from PBMCs primed with a TLR3 agonist enhanced TLR2/6 agonist stimulated production of IL-6 and IL-8, suggesting a differential response by the placenta to systemic inflammation compared to direct infection as a result of haematogenous spread. TLR3 agonism generally caused increased mRNA expression of TLR3 and TLR2 but not TLR6. Conclusion: This study provides human in vitro evidence that viral infection may increase the susceptibility of women to bacterial-induced sPTB. Improved understanding of interactions between viral and bacterial components of the maternal microbiome and host immune response may offer new therapeutic options, such as antivirals for the prevention of PTB.

Human Amnion Epithelial Cells (AECs) Respond to the FSL-1 Lipopeptide by Engaging the NLRP7 Inflammasome.

Context and Objectives: Inflammation is the leading mechanism involved in both physiological and pathological rupture of fetal membranes. Our aim was to obtain a better characterization of the inflammasome-dependent inflammation processes in these tissues, with a particular focus on the nucleotide-binding oligomerization domain (NOD)-like receptor, pyrin domain containing protein 7 (NLRP7) inflammasome. Methods: The presence of NLRP7 inflammasome actors [NLRP7, apoptosis-associated speck-like protein containing a CARD domain (ASC), and caspase-1] was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) in human amnion and choriodecidua at the three trimesters and at term. The protein concentrations were then determined by enzyme-linked immunosorbent assay in term tissues, with or without labor. The presence of Mycoplasma salivarium and Mycoplasma fermentans in human fetal membranes was investigated using a PCR approach. Human amnion epithelial cells (AECs) were treated for 4 or 20 h with fibroblast-stimulating lipopeptide-1 (FSL-1), a M. salivarium-derived ligand. Transcripts and proteins quantity was then measured by RT-quantitative PCR and Western blotting, respectively. NLRP7 and ASC colocalization was confirmed by immunofluorescence. Western blots allowed analysis of pro-caspase-1 and gasdermin D cleavage. Results: NLRP7, ASC, and caspase-1 transcripts were expressed in both sheets of human fetal membranes during all pregnancy stages, but only ASC protein expression was increased with labor. In addition, M. salivarium and M. fermentans were detected for the first time in human fetal membranes. NLRP7 and caspase-1 transcripts, as well as NLRP7, ASC, and pro-caspase-1 protein levels, were increased in FSL-1-treated AECs. The NLRP7 inflammasome assembled around the nucleus, and pro-caspase-1 and gasdermin D were cleaved into their mature forms after FSL-1 stimulation. Conclusion: Two new mycoplasmas, M. salivarium and M. fermentans, were identified in human fetal membranes, and a lipopeptide derived from M. salivarium was found to induce NLRP7 inflammasome formation in AECs.

Porphyromonas gingivalis, a cause of preterm birth in mice, induces an inflammatory response in human amnion mesenchymal cells but not epithelial cells.

INTRODUCTION: Inflammation and infection, including dental infectious diseases, are factors that can induce preterm birth. We previously reported that mice with dental Porphyromonas gingivalis infection could be used as a model of preterm birth. In this model, cyclooxygenase (COX)-2 and interleukin (IL)-1ß levels are increased, and P. gingivalis colonies are observed in the fetal membrane. However, the mechanism underlying fetal membrane inflammation remains unknown. Therefore, we investigated the immune responses of human amnion to P. gingivalis in vitro. METHODS: Epithelial and mesenchymal cells were isolated from human amnion using trypsin and collagenase, and primary cell cultures were obtained. Confluent cells were stimulated with P. gingivalis lipopolysaccharide (P.g-LPS) or P. gingivalis. mRNA expressions of IL-1ß, IL-8, IL-6 and COX-2, protein expressions of nuclear factor (NF)-κB pathway components and culture medium levels of prostaglandin E2 were evaluated. RESULTS: Following stimulation with 1 µg/mL P.g-LPS, the mRNA expression levels of IL-1ß, IL-8, IL-6 and COX-2 in mesenchymal cells were increased 5.9-, 3.3-, 4.2- and 3.1-fold, respectively. Similarly, the expression levels of IL-1ß, IL-8, IL-6 and COX-2 in mesenchymal cells were increased by 7.6-, 8.2-, 13.4- and 9.3-fold, respectively, after coculture with P. gingivalis. Additionally, stimulation with P.g-LPS or P. gingivalis resulted in the activation of NF-κB signaling and increased production of IL-1ß and prostaglandin E2. In contrast, no significant changes were observed in epithelial cells. DISCUSSION: Our findings suggest that mesenchymal cells might mediate the inflammatory responses to P. gingivalis and P.g-LPS, thereby producing inflammation that contributes to the induction of preterm birth.

Inflammation, but not infection, induces EMT in human amnion epithelial cells.

A non-reversible state of epithelial to mesenchymal transition (EMT) at term accumulates proinflammatory mesenchymal cells and predisposes fetal membrane to weakening prior to delivery at term. We investigated the induction of EMT in amnion epithelial cells (AEC) in response to inflammation and infection associated with spontaneous preterm birth (SPTB). For this, membranes from SPTB were screened for EMT markers. Primary AEC in culture were treated with TNF-α (10 and 50 ng/mL) and LPS (50 and 100 ng/mL) for 72 h. Cell shape index (SI) was determined based on morphological shift (microscopy followed by ImageJ software analysis). Immunocytochemistry and Western blot assessed changes in epithelial markers (cytokeratin-18 and E-cadherin) and mesenchymal markers (vimentin and N-cadherin). Involvement of transforming growth factor beta (TGF-ß) in EMT induction and EMT associated inflammation was tested using specific markers (Western blot) and by measuring MMP9 (ELISA), respectively. We report that PTB is associated with fetal membrane EMT. TNF-α produced dose- and time-dependent induction of EMT; within 24 h by 50 ng/mL and after 72 h by 10 ng/mL. AEC showed mesenchymal morphology, lower E-cadherin, higher vimentin and N-cadherin and higher MMP9 compared to control. TNF-α-induced EMT was not associated with canonical TGF-ß pathway. LPS, regardless of dose or time, did not induce EMT in AEC. We conclude that PTB with intact membranes is associated with EMT. Our data suggest that inflammation, but not infection, is associated with non-canonical activation of EMT and inflammation that can predispose membrane to undergo weakening.

Altered productions of prostaglandins and prostamides by human amnion in response to infectious and inflammatory stimuli identified by mutliplex mass spectrometry.

INTRODUCTION: Prostaglandins are critical for the onset and progression of labor in mammals, and are formed by the metabolism of arachidonic acid. The products of arachidonic acid, 2-arachidonoylglycerol (2-AG), and anandamide (AEA) have a similar lipid back bone but differing polar head groups, meaning that identification of these products by immunoassay can be difficult. MATERIALS AND METHODS: In the current study, we present the use of mass spectrometry as multiplex method of identifying the specific end products of arachidonic and anandamide metabolism by human derived amnion explants treated with either an infectious agent (LPS) or inflammatory mediator (IL-1ß or TNF-α). RESULTS: Human amnion tissue explants treated with LPS, IL-1ß, or TNF-α increased production of prostaglandin E2 (PGE2; p < 0.05) but decreased PGFM. Overall, PGE2 production was greater compared to the other prostaglandins and prostamides irrespective of treatment. CONCLUSIONS: The findings of the current study are in keeping with the literature which describes amnion tissues as predominantly producing PGE2. The use of mass spectrometry for the differential identification of prostaglandins, prostamides, and other eicosanoids may help better elucidate mechanisms of preterm labor, and lead to new targets for the prediction of risk for preterm labor and/or birth.

Granulocyte macrophage colony stimulating factor (GM-CSF), the critical intermediate of inflammation-induced fetal membrane weakening, primarily exerts its weakening effect on the choriodecidua rather than the amnion.

INTRODUCTION: We have previously demonstrated two associations of PPROM, (1) inflammation/infection (modeled by tumor necrosis factor (TNF)) and (2) decidual bleeding (modeled by thrombin), both decrease fetal membrane (FM) rupture strength in-vitro. Furthermore, Granulocyte-Macrophage-Colony-Stimulating-Factor (GM-CSF) induced by both TNF and thrombin is a critical intermediate, necessary and sufficient for weakening by either agent. The amnion is the strength component of FM and must weaken for FM to rupture. It is unclear whether GM-CSF weakens amnion (AM) directly, or initially targets choriodecidua (CD) which secondarily releases agents to act on amnion. METHODS: Full thickness FM fragments were treated with/without GM-CSF. Some were preincubated with alpha-lipoic acid (LA), a known inhibitor of FM weakening. The FM fragments were then strength-tested. Separately, FM fragments were initially separated to AM and CD. AM fragments were cultured with Medium ± GM-CSF and then strength-tested. In other experiments, CD fragments were cultured with Medium, GM-CSF, LA, or LA + GM-CSF. Conditioned medium from each group was then incubated with AM. AM was then strength-tested. Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Matrix Metalloproteinases (TIMPs) were analyzed by Mutiplex Elisa. RESULTS: GM-CSF weakened intact FM which was blocked by LA. GM-CSF did not weaken isolated AM. However, GM-CSF conditioned CD media weakened AM and this weakening was inhibited by LA. GM-CSF treatment of CD increased MMPs 2, 9, and 10, and decreased TIMPs 1-3. LA reversed these effects. CONCLUSIONS: GM-CSF does not weaken amnion directly; GM-CSF acts on CD to increase proteases and decrease anti-proteases which secondarily weaken the amnion.

Increased Soluble Epoxide Hydrolase in Human Gestational Tissues from Pregnancies Complicated by Acute Chorioamnionitis.

Chorioamnionitis (CAM) is primarily a polymicrobial bacterial infection involving chorionic and amniotic membranes that is associated with increased risk of preterm delivery. Epoxyeicosatrienoic acids (EETs) are eicosanoids generated from arachidonic acid by cytochrome P450 enzymes and further metabolized mainly by soluble epoxide hydrolase (sEH) to produce dihydroxyeicosatrienoic acids (DHETs). As a consequence of this metabolism of EETs, sEH reportedly exacerbates several disease states; however, its role in CAM remains unclear. The objectives of this study were to (1) determine the localization of sEH and compare the changes it undergoes in the gestational tissues (placentas and fetal membranes) of women with normal-term pregnancies and those with pregnancies complicated by acute CAM; (2) study the effects of lipopolysaccharide (LPS) on the expression of sEH in the human gestational tissues; and (3) investigate the effect of 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), a specific sEH inhibitor, on LPS-induced changes in 14,15-DHET and cytokines such as interleukin- (IL-) 1ß and IL-6 in human gestational tissues in vitro and in pregnant mice. We found that women with pregnancies complicated by acute CAM had higher levels of sEH mRNA and protein in fetal membranes and villous tissues compared to those in women with normal-term pregnancies without CAM. Furthermore, fetal membrane and villous explants treated with LPS had higher tissue levels of sEH mRNA and protein and 14,15-DHET than those present in the vehicle controls, while the administration of AUDA in the media attenuated the LPS-induced production of 14,15-DHET in tissue homogenates and IL-1ß and IL-6 in the media of explant cultures. Administration of AUDA also reduced the LPS-induced changes of 14,15-DHET, IL-1ß, and IL-6 in the placentas of pregnant mice. Together, these results suggest that sEH participates in the inflammatory changes in human gestational tissues in pregnancies complicated by acute CAM.

Effects of hyaluronic acid on differentiation of human amniotic epithelial cells and cell-replacement therapy in type 1 diabetic mice.

Our hypothesis is that hyaluronic acid may regulate the differentiation of human amniotic epithelial cells (hAECs) into insulin-producing cells and help the treatment of type 1 diabetes. Herein, a protocol for the stepwise in vitro differentiation of hAECs into functional insulin-producing cells was developed by mimicking the process of pancreas development. Treatment of hAECs with hyaluronic acid enhanced their differentiation of definitive endoderm and pancreatic progenitors. Endodermal markers Sox17 and Foxa2 and pancreatic progenitor markers Pax6, Nkx6.1, and Ngn3 were upregulated an enhanced gene expression in hAECs, but hAECs did not express the ß cell-specific transcription factor Pdx1. Interestingly, hyaluronic acid promoted the expression of major pancreatic development-related genes and proteins after combining with commonly used inducers of stem cells differentiation into insulin-producing cells. This indicated the potent synergistic effects of the combination on hAECs differentiation in vitro. By establishing a multiple injection transplantation strategy via tail vein injections, hAECs transplantation significantly reduced hyperglycemia symptoms, increased the plasma insulin content, and partially repaired the islet structure in type 1 diabetic mice. In particular, the combination of hAECs with hyaluronic acid exhibited a remarkable therapeutic effect compared to both the insulin group and the hAECs alone group. The hAECs' paracrine action and hyaluronic acid co-regulated the local immune response, improved the inflammatory microenvironment in the damaged pancreas of type 1 diabetic mice, and promoted the trans-differentiation of pancreatic α cells into ß cells. These findings suggest that hyaluronic acid is an efficient co-inducer of the differentiation of hAECs into functional insulin-producing cells, and hAECs treatment with hyaluronic acid may be a promising cell-replacement therapeutic approach for the treatment of type 1 diabetes.

Propofol Suppresses LPS-Induced Inflammation in Amnion Cells via Inhibition of NF-κB Activation.

Background: Preterm labor is a leading risk factor for neonatal death and long-term impairment and linked closely with inflammation. Non-obstetric surgery is occasionally needed during pregnancy and the anesthetic drugs or surgery itself can give rise to inflammation. Here, we examined the influence of propofol pretreatment on the expression of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) after lipopolysaccharide (LPS) stimulation. In addition, we evaluated the expression of pro-inflammatory cytokines and nuclear factor kappa B (NF-κB). Methods: Human amnion-derived WISH cells were used to investigate the effect of propofol on the LPS-induced expression of inflammatory substances involved in preterm labor. For the experiment, WISH cells were pretreated with various concentrations propofol (0.01-10 µg/ml) for 1 h and then treated with LPS (1 µg/ml) for 24 h. Cytotoxicity was evaluated using MTT assay. PGE2 concentration was assessed by ELISA. Protein expressions of COX-2, PGE2 and NF-κB were analyzed by western blotting analysis. RT-PCR was used for analysis of mRNA expression of COX-2, PGE2, interlukin (IL)-1ß and tumor necrosis factor (TNF)-α. Results: Propofol showed no cytotoxicity on the WISH cells. LPS-induced PGE2 production and COX-2 and PGE2 expression were decreased after propofol pretreatment. Propofol also attenuated the LPS-induced mRNA expression of IL-1ß and TNF-α. Moreover, the activation of NF-κB was inhibited by propofol pretreatment on LPS-stimulated WISH cells. Conclusion: We demonstrated that propofol suppresses the expression of inflammatory substances enhanced by LPS stimulation. Furthermore, this inhibitory effect of propofol on the inflammatory substance expression is mediated by suppression of NF-κB activation.

Microengineered human amniotic ectoderm tissue array for high-content developmental phenotyping.

During early post-implantation human embryogenesis, the epiblast (EPI) within the blastocyst polarizes to generate a cyst with a central lumen. Cells at the uterine pole of the EPI cyst then undergo differentiation to form the amniotic ectoderm (AM), a tissue essential for further embryonic development. While the causes of early pregnancy failure are complex, improper lumenogenesis or amniogenesis of the EPI represent possible contributing factors. Here we report a novel AM microtissue array platform that allows quantitative phenotyping of lumenogenesis and amniogenesis of the EPI and demonstrate its potential application for embryonic toxicity profiling. Specifically, a human pluripotent stem cell (hPSC)-based amniogenic differentiation protocol was developed using a two-step micropatterning technique to generate a regular AM microtissue array with defined tissue sizes. A computer-assisted analysis pipeline was developed to automatically process imaging data and quantify morphological and biological features of AM microtissues. Analysis of the effects of cell density, cyst size and culture conditions revealed a clear connection between cyst size and amniogenesis of hPSC. Using this platform, we demonstrated that pharmacological inhibition of ROCK signaling, an essential mechanotransductive pathway, suppressed lumenogenesis but did not perturb amniogenic differentiation of hPSC, suggesting uncoupled regulatory mechanisms for AM morphogenesis vs. cytodifferentiation. The AM microtissue array was further applied to screen a panel of clinically relevant drugs, which successfully detected their differential teratogenecity. This work provides a technological platform for toxicological screening of clinically relevant drugs for their effects on lumenogenesis and amniogenesis during early human peri-implantation development, processes that have been previously inaccessible to study.

Insulin-Transferrin-Selenium as a Novel Serum-free Media Supplement for the Culture of Human Amnion Mesenchymal Stem Cells

This study aimed to evaluate the use of Insulin-Transferrin-Selenium (ITS) medium in place of fetal bovine serum (FBS) to culture human amnion mesenchymal stem cells (hAMSCs). Cell morphology, ultrastructure, proliferation, migration and MSC related markers were assessed accordingly. The hAMSCs were induced to osteocyte, chondrocyte, adipocyte and keratinocyte by culturing in appropriate induction medium. hAMSCs mRNA expression was detected for the matrix metalloproteinases 2 (MMP2), keratinocyte growth factor (KGF), vascular endothelial growth factor (VEGF), insulin-like growth factor-I (IGF-I), Platelet-derived Growth Factor (PDGF), and transforming growth factor beta 1 (TGF-ß) by real-time quantitative RT-PCR. Our results showed that hAMSCs cultured in ITS medium exhibited similar proliferation rates, demonstrated a statistically significant increased migration and expressed similar levels of MSC markers(CD73+, CD90+, CD105+, CD45-, CD34-) compared with those cultured in FBS. Osteoblasts, chondrocytes, adipocytes and keratinocytes were differentiated. Results of transmission electron microscope (TEM) revealed that hAMSCs cultured in ITS medium underwent active metabolism. The mRNA expression of MMP2, VEGF, KGF, TGF-ß, IGF-I and PDGF upregulated in ITS medium. In conclusion, ITS medium has the potential to be used for the expansion of hAMSCs before clinical application.

Dexamethasone induces primary amnion epithelial cell senescence through telomere-P21 associated pathway†.

Dexamethasone (Dex), a corticosteroid hormone, is used during the perinatal period to help fetal lung and other organ development. Conversely, Dex-induced cell proliferation has been associated with accelerated aging. Using primary amnion epithelial cells (AECs) from term, not in labor, fetal membranes, we tested the effects of Dex on cell proliferation, senescence, and inflammation. Primary AECs treated with Dex (100 and 200 nM) for 48 h were tested for cell viability (crystal violet dye exclusion), cell cycle progression and/or type of cell death (flow cytometry), expression patterns of steroid receptors (glucocorticoid receptor, progesterone receptor membrane component 1&2), inflammatory mediators (IL-6 and IL-8), and telomere length (quantitative RT-PCR). Mechanistic mediators of senescence (p38MAPK and p21) were determined by western blot analysis. Dex treatment did not induce AEC proliferation, cell cycle, influence viability, or morphology. However, Dex caused dependent telomere length reduction and p38MAPK-independent but p21-dependent (confirmed by treatment with p21 inhibitor UC2288). Senescence was not associated with an increase in inflammatory mediators, which is often associated with senescence. Co-treatment with RU486 produced DNA damage, cell cycle arrest, and cellular necrosis with an increase in inflammatory mediators. The effect of Dex was devoid of changes to steroid receptors, whereas RU486 increased GR expression. Dex treatment of AECs produced nonreplicative and noninflammatory senescence. Extensive use of Dex during the perinatal period may lead to cellular senescence, contributing to cellular aging associated pathologies during the perinatal and neonatal periods.