Transplanted artificial amnion membrane enhanced wound healing in third-degree burn injury diabetic mouse model

Introduction

Wound healing is severely compromised in patients with diabetes owing to factors such poor blood circulation, delayed immune response, elevated blood sugar levels, and neuropathy. Although the development of new wound healing products and prevention of serious complications such as infections in wounds have received substantial interest, wound healing remains a challenge in regenerative medicine. Burn wounds, especially third-degree burns, are difficult to treat because they are associated with immune and inflammatory reactions and distributive shock. Wound care and treatment that protects the burn site from infection and allows wound healing can be achieved with bioengineered wound dressings. However, few studies have reported effective dressings for third-degree burn wounds, making it important to develop new dressing materials.

Methods

In this study, we developed an artificial amniotic membrane (AM) using epithelial and mesenchymal cells derived from human amnion as a novel dressing material. The artificial AM was applied to the wound of a diabetic third-degree burn model and its wound healing ability was evaluated.

Results

This artificial amnion produced multiple growth factors associated with angiogenesis, fibroblast proliferation, and anti-inflammation. In addition, angiogenesis and granulation tissue formation were promoted in the artificial AM-treated mouse group compared with the control group. Furthermore, the inflammatory phase was prolonged in the control group.

Conclusions

Our preliminary results indicate that the artificial AM might be useful as a new dressing for refractory ulcers and third-degree burns. This artificial AM-based material represents great potential for downstream clinical research and treatment of diabetes patients with third-degree burns.

Chorion and amnion/chorion membranes in oral and periodontal surgery: A systematic review

The aim of this study was to perform a systematic review on the clinical applications where chorion membrane (CM) and amnion/chorion membrane (ACM) were used for oral tissue regeneration procedures. Selection of articles was carried out by two evaluators in Pubmed and Scopus databases, and Outcomes (PICO) method was used to select the relevant articles. Clinical studies reporting the use of CM or ACM for oral soft and hard tissue regeneration were included. The research involved 21 studies conducted on 375 human patients. Seven clinical applications of CM and ACM in oral and periodontal surgery were identified: gingival recession treatment, intrabony and furcation defect treatment, alveolar ridge preservation, keratinized gum width augmentation around dental implants, maxillary sinus membrane repair, and large bone defect reconstruction. CM and ACM were compared to negative controls (conventional surgeries without membrane) or to the following materials: collagen membranes, dense polytetrafluoroethylene membranes, platelet-rich fibrin membranes, amnion membranes, and to a bone substitute. Several studies support the use of CM and ACM as an efficient alternative to current techniques for periodontal and oral soft tissue regeneration procedures. However, further studies are necessary to increase the level of evidence and especially to demonstrate their role for bone regeneration.

Update review on five top clinical applications of human amniotic membrane in regenerative medicine

Due to the increasing number of studies performed in the field of regenerative medicine during the last two decades, more analytic studies are still needed to clarify the future prospect of this area of science. The main aim of this research was to review the clinical applications of human Amniotic membrane in the field of regenerative medicine critically. Furthermore, in the light of increasing numbers of available products derived from amniotic membrane, we aimed look in depth to see whether regenerative medicine research strategies have a place in the clinical setting. More specifically, in the present study, we attempted to provide insight on developing the new indication for more research and in the next step, for market leaders companies to expand cost-effectiveness of new derived AM products. 20 companies or distributers have offered some commercial products in this field. Survey on more than 90 clinical trials in last five years showed dermatology (and more specific wound healing), orthopedic, and ophthalmology are heavily biased toward multibillion dollar industry. Moreover, urology and dentistry with fewer numbers of clinical data in comparison with the above-mentioned areas, currently are in the path of translation (especially dentistry). In addition, otolaryngology and oncology with the lowest number showed more potential of research thorough understanding the properties that will help guiding the use of AM-derived products in these two areas in future. More than 50% of clinical studies were done or are developing in USA, which have the biggest share in market products. Subsequently, China, Egypt, India, Iran, and Germany with the ongoing clinical trials in different phases may have more approved products in near future.

Efficacy of self-retained cryopreserved amniotic membrane for treatment of neuropathic corneal pain

PURPOSE

Treatment of neuropathic corneal pain (NCP) remains intricate, and involves a long-term combined multistep approach. The self-retained cryopreserved amniotic membrane (PROKERA®, Bio-Tissue, Miami,FL) has been utilized for multiple ocular surface disorders. We evaluate the efficacy, safety, and tolerability of ProKera® Slim [PKS] and ProKera® Clear [PKC] in the treatment of NCP.

METHODS

Retrospective case series of 9 patients who received PKS/PKC for the acute treatment of NCP. Patient demographics, prior therapies, clinical examination, duration of PKS/PKC retention, changes in pain severity, corneal subbasal nerve density and morphology by in vivo confocal microscopy (IVCM; HRT3/RCM, Heidelberg Engineering, Heidelberg, Germany), and adverse events were recorded.

RESULTS

PKS/PKC were placed in 10 eyes of 9 patients. Pain severity improved by 72.5 ± 8.4% (from 6.3 ± 0.8 to 1.9 ± 0.6, scale 1-10, p = 0.0003) after retention for 6.4 ± 1.1 days. Despite shorter retention for 4.0 ± 0.7 days in patients with ring dysesthesia (4 eyes) or premature implant disengagement (2 eyes), pain severity still improved by 63.1 ± 12.5% (from 6.8 ± 1.0 to 2.4 ± 0.9, p = 0.009). During a follow-up of 9.3 ± 0.8 months, two patients reported recurrence of pain after 2.3 and 9.6 months respectively, treated effectively with additional PKS/PKC. IVCM showed a 36.6 ± 17.6% increase in total nerve density, from 17,700.9 ± 1315.7 to 21,891.3 ± 2040.5 μm/mm2 (p = 0.047), while the fellow PKS/PKC-untreated eyes did not show a significant interval change. Main nerve trunk and branch nerve densities were not statistically different. Dendritiform cell density decreased from 46.0 ± 8.2 to 32.0 ± 6.0 cells/mm2 (p = 0.01).

CONCLUSIONS

PKS/PKC provide a safe and effective treatment approach to achieve sustained pain control in patients with NCP.

Use of Amnion Transfer in Resistant Nonhealing Venous Leg Ulcers

In the treatment of venous leg ulcers, after adopting many treatment modalities, at times we are still left with a local indolent problem, "the resistant nonhealing venous ulcer." With repeated surgical procedures failing to obtain a healed ulcer, constant pain, persistent discharging wound, infections, etc., many a patient turn hostile. Also, there comes a dimension of despair in the health feeling of the patient. This prospective study was conducted in 40 patients, who were within the inclusion criteria (January 2006-January 2010, 12 males and 28 females, mean age 45 years). A single amniotic membrane (AM) transfer was done after preparation of the wound, and the parameters were assessed periodically. Follow-up for a minimum period of 1 year in all cases and a maximum period of 3 years in many cases (38) was done. Significant clinical response was defined as an ulcer healing greater than 75 % of the original area. Treatment failure was taken as a persistence or recurrence of more than 25 % of the ulcer area in a 1-year follow-up period. The preliminary results of good ulcer healing and no recurrence are encouraging, even up to 3-year follow-up. This proof-of-concept study demonstrates that AM transfer is useful, safe, inexpensive, readily available, and well accepted by patients, with tremendous potential in promoting epithelial healing in "the resistant nonhealing chronic venous leg ulcer."

A critical role of interleukin-1 in preterm labor

Preterm birth (PTB) is a leading cause of neonatal mortality and morbidity worldwide, and represents a heavy economic and social burden. Despite its broad etiology, PTB has been firmly linked to inflammatory processes. Pro-inflammatory cytokines are produced in gestational tissues in response to stressors and can prematurely induce uterine activation, which precedes the onset of preterm labor. Of all cytokines implicated, interleukin (IL)-1 has been largely studied, revealing a central role in preterm labor. However, currently approved IL-1-targeting therapies have failed to show expected efficacy in pre-clinical studies of preterm labor. Herein, we (a) summarize animal and human studies in which IL-1 or IL-1-targeting therapeutics are implicated with preterm labor, (b) focus on novel IL-1-targeting therapies and diagnostic tests, and (c) develop the case for commercialization and translation means to hasten their development.

Umbilical cord prostaglandins in term and preterm parturition

OBJECTIVE

Prostaglandins (PGs) are considered the universal mediators of parturition. Amniotic fluid PGE2 and PGF2α concentrations increase before the onset of spontaneous labor at term, as well as during labor. This study was conducted to determine if the concentrations of umbilical cord PGE2 and PGF2α change with advancing gestational age, spontaneous labor at term, and preterm labor (with and without funisitis).

METHODS

Umbilical cord (UC) tissue samples were obtained from women (N = 158) with singleton pregnancies in the following groups: (1) term deliveries without labor (TNL; n = 20); (2) term deliveries with labor (TIL; n = 20); (3) spontaneous preterm deliveries (sPTD) with (n = 20) and without acute funisitis (n = 20); and (4) preeclampsia without labor (n = 78). The concentrations of PGs were determined in different locations of the UC. PGE2 and PGF2α were measured by specific immunoassays. Non-parametric statistics were used for analysis.

RESULTS

(1) In spontaneous preterm deliveries, the median UC PGE2 concentration was higher in cases with funisitis than in those without funisitis (233.7 pg/µg versus 87.4 pg/µg of total protein, p = 0.001); (2) the median UC PGE2 concentration in sPTD with funisitis was also higher than that obtained from samples who had undergone labor at term (233.7 pg/µg versus 116.1 pg/µg of total protein, p = 0.03); (3) the UC PGE2 and PGF2α concentration increased as a function of advancing gestational age before 36 weeks (PGE2: ρ = 0.59, p < 0.001; PGF2α: ρ = 0.39, p = 0.01), but not after 36 weeks (PGE2: ρ = -0.1, p = 0.5; PGF2α: ρ = -0.2, p = 0.2); (4) the median UC concentrations of PGE2 and PGF2α at term was similar in samples obtained from women with and without labor (PGE2: TNL 133.7 pg/µg versus TIL 116.1 pg/µg of total protein, p = 0.9; PGF2α: TNL 8.4 pg/µg versus TIL 8.1 pg/µg of total protein, p = 0.7); and (5) there was no correlation between UC PG concentration and gestational age at term pregnancy (PGE2: ρ = 0.01, p = 0.9; PGF2α: ρ = 0.07, p = 0.7).

CONCLUSIONS

(1) PGE2 concentrations in the UC are higher in the presence of acute funisitis than in the absence of this lesion; (2) spontaneous labor at term was not associated with a change in the UC concentration of PGE2 and PGF2α; and (3) the UC concentrations of PGE2 and PGF2α increased as a function of gestational age. We propose that UC PGs act as inflammatory mediators generated in the context of fetal systemic inflammation.

Clinical effect of bovine amniotic membrane and hydrocolloid on wound by laser treatment: prospective comparative randomized clinical trial

Bovine amniotic membrane (BAM) has been regarded as an ideal dressing material because it accelerates epithelization and has anti-inflammatory, anti-angiogenic, and strong analgesic effects. To evaluate the clinical effects of BAM and compare them to that of hydrocolloid dressings on wounds created by ablative laser treatments, 49 subjects with nevi or scars requiring ablative laser treatment were evaluated. To compare efficacy, we divided the body into six areas and included patients with two or more similar skin lesions in the same body area. After ablative laser treatments, BAM and hydrocolloid dressing were applied to the wounds with random allocation. Clinical assessments were performed at baseline, 1, 4, 6, 8, 11, and 13 days after treatment. Histologic changes were assessed by skin biopsy. BAM treatment induced faster epithelization than hydrocolloid treatment (6.7 vs. 9.2 days). Erythema and oozing faded more quickly, and the satisfaction score was higher in BAM-treated sites than it was in hydrocolloid-treated sites, without severe adverse effects. Histologic analysis confirmed epithelization and immunohistochemistry revealed different growth factor profiles between the two treatment modalities. BAM benefits wound healing following ablative laser treatment.

Assessment of cervicovaginal vascular endothelial growth factor in predicting preterm delivery

AIM

The aim of this study is to estimate the effectiveness of cervicovaginal vascular endothelial growth factor (VEGF) in predicting preterm delivery.

METHODS

Cervicovaginal VEGF was measured in 30 women who presented symptoms or signs of threatened preterm labor and the control group of 30 healthy pregnant patients by enzyme-linked immunoassay.

RESULTS

There was no statistically significant difference in cervicovaginal VEGF values between the threatened preterm labor group and the control group (P > 0.05). Similarly, no statistically significant difference was observed in terms of cervical length and cervicovaginal VEGF values between preterm and term-delivered groups (P > 0.05). Additionally, there was no correlation between cervicovaginal VEGF values and cervical length (P > 0.05) between the threatened preterm labor and the control groups.

CONCLUSION

No correlation was found between cervicovaginal VEGF values and the preterm delivery. However, we believe that the role of VEGF in preterm delivery needs to be investigated further in well-designed studies with larger samples.

The effects of labor on differential gene expression in parturient women, placentas, and fetuses at term pregnancy

Labor and its associated pain are thought to have unique impacts on parturient women. The goal of this study was to investigate the effects of labor and associated pain on differential gene expression profiles in the maternal, fetal, and placental compartments. We used microarrays to analyze maternal blood (MB), fetal cord blood (CB), and placental tissue samples in pregnant women after term vaginal deliveries (laboring group) and in term pregnant women after scheduled Ceasarean sections (nonlaboring group). The upregulated genes in the MB of the laboring group are involved in cytokine and nuclear factor-kappa B signaling pathways, regulation of the networks of toll-like receptor 4, and suppressor of cytokine signaling 3. Upregulated genes in the CB of the laboring group are involved in responding to stress and stimuli by regulating the network genes of the T-cell receptor beta locus and the FK506 binding protein 8. Differentially expressed genes in the placenta of the laboring group are involved in nitric oxide transport, gas transport, response to hydrostatic pressure, oxygen transport, acute phase responses, and the tumor necrosis factor-mediated signaling pathway, which are important during the transient hypoxemia and hypoperfusion that occur in the placenta during uterine contractions. Interestingly, few of the genes exhibited simultaneous changes in all three compartments, indicating that different pathways and complex interactions may be involved in human labor. In conclusion, human labor and its associated pain elicit unique gene regulatory changes in MB, placenta, and CB.

Evidence in support of a role for anti-angiogenic factors in preterm prelabor rupture of membranes

OBJECTIVE

Vaginal bleeding, placental abruption, and defective placentation are frequently observed in patients with preterm prelabor rupture of membranes (PROM). Recently, a role of vascular endothelial growth factor (VEGF) and its receptor, VEGF receptor (VEGFR)- 1 has been implicated in the mechanisms of membrane rupture. The purpose of this study was to determine whether the soluble form of VEGFR-1 and -2 concentrations in amniotic fluid (AF) change with preterm PROM, intra-amniotic infection/inflammation (IAI), or parturition.

STUDY DESIGN

This cross-sectional study included 544 patients in the following groups: (1) midtrimester (MT) (n = 48); (2) preterm labor (PTL) leading to term delivery (n = 143); (3) PTL resulting in preterm delivery with (n = 72) and without IAI (n = 100); (4) preterm PROM with (n = 46) and without IAI (n = 42); (5) term in labor (n = 48); and (6) term not in labor (n = 45). The concentrations of sVEGFR-1 and sVEGFR-2 were determined by ELISA. Non-parametric statistics and logistic regression analysis were applied.

RESULTS

(1) Preterm PROM (with and without IAI) had a lower median AF concentration of sVEGFR-1 than patients with PTL who delivered at term (p < 0.001 for each comparison); (2) A decrease in AFsVEGFR-1 concentrations per each quartile was associated with PROM after adjusting for confounders (OR 1.8; 95%CI 1.4-2.3); (3) IAI, regardless of the membrane status, was not associated with a change in the median AF concentrations of sVEGFR-1 and sVEGFR-2 (p > 0.05 for each comparison); and (4) Spontaneous term and PTL did not change the median sVEGFR-1 and sVEGFR-2 concentrations (p > 0.05 for each comparison).

CONCLUSION

(1) This is the first evidence that preterm PROM is associated with a lower AF concentration of sVEGFR-1 than patients with PTL intact membranes. These findings cannot be attributed to gestational age, labor, or IAI; and (2) AF concentrations of sVEGFR-2 did not change with preterm PROM, IAI, or labor at term and preterm.

A subset of patients destined to develop spontaneous preterm labor has an abnormal angiogenic/anti-angiogenic profile in maternal plasma: evidence in support of pathophysiologic heterogeneity of preterm labor derived from a longitudinal study

OBJECTIVE

An imbalance between angiogenic and anti-angiogenic factors in maternal blood has been observed in several obstetrical syndromes including preeclampsia, pregnancies with fetal growth restriction and fetal death. Vascular lesions have been identified in a subset of patients with spontaneous preterm labor (PTL). It is possible that PTL may be one of the manifestations of an anti-angiogenic state. The aim of this study was to determine if patients prior to the clinical diagnosis of PTL leading to preterm delivery had plasma concentrations of angiogenic and anti-angiogenic factors different from normal pregnant women.

STUDY DESIGN

This longitudinal nested case-control study included normal pregnant women (n = 208) and patients with PTL leading to preterm delivery (n = 52). Maternal blood samples were collected at 6 gestational age intervals from 6 to 36.9 weeks of gestation. The end point (time of diagnosis) of the study, 'True PTL', was defined as patients presenting with PTL and delivered within 1 day. Plasma concentrations of sVEGFR-1, sVEGFR-2, sEng and PlGF were determined by ELISA. Analysis was performed with both cross-sectional and longitudinal (mixed effects model) approaches.

RESULTS

(1) Plasma sEng concentration in patients destined to develop PTL was higher than that in normal pregnant women from 15-20 weeks of gestation. The difference became statistical significant at 28 weeks of gestation, or approximately 5-10 weeks prior to the diagnosis of 'true PTL'. (2) Backward analysis suggests that plasma concentrations of PlGF and sVEGFR-2 were lower, and those of sVEGFR-1 were higher in patients with PTL than in normal pregnant women less than 5 weeks prior to the diagnosis of 'true PTL'; and (3) Plasma concentrations of sEng and sVEGFR-1 were higher and those of PlGF and sVEGFR-2 were lower in patients diagnosed with PTL and delivery within 1 day than in normal pregnant women who delivered at term.

CONCLUSION

The changes in sEng are demonstrable several weeks prior to the onset of preterm parturition. In contrast, the changes in the other angiogenic proteins are present close to the onset of PTL and delivery. This observation supports the view that an imbalance of angiogenic factors participates in the pathophysiology of spontaneous preterm parturition.

Vascular endothelial growth factor gene polymorphisms and pregnancy

Vascular endothelial growth factor (VEGF) is a major angiogenic factor and prime regulator of endothelial cell proliferation. During pregnancy, VEGF is essential for the proliferation of trophoblasts, the development of embryonic vasculature and the growth of maternal and fetal blood cells in utero. In cases of pre-eclampsia and in some circumstances of preterm labor-raised umbilical cord serum, VEGF levels might be correlated with the clinical development of the above pathological disorders. Genetic alteration as 936C/T VEGF gene polymorphism has a statistical significant correlation with the severity of pre-eclampsia. The same VEGF gene polymorphism, which has been associated with lower protein production, has an increased risk of spontaneous preterm delivery in a Greek-studied population. Homozygotes were found to carry the greatest risk with a lesser proportionate risk associated with heterozygosity, whereas women with the -1154 allele of the VEGF gene have an increased risk of recurrent pregnancy loss. In this review, we present evidence that demonstrates an implication of VEGF gene polymorphisms in the pathological disorders of pregnancy. However, further genetic studies are needed to confirm these data.

Effects of the Human Amniotic Membrane on Axonal Outgrowth of Dorsal Root Ganglia Neurons in Culture

PURPOSE

In order to investigate the potential underlying neurotrophic mechanisms of human amniotic membrane (AM) in the treatment of neurotrophic corneal ulcers, we evaluated whether or not there are significant differences in the neuritic growth of neuronal cell cultures on different surfaces of AM.

METHODS

Neurite outgrowth of dorsal root ganglia neurons was examined under two separate conditions: (1) in serum-free medium consisting of minimal essential medium (MEM), glucose, and L-glutamine, (2) in same medium additionally supplemented with horse serum, chick embryonic extract, and nerve growth factor. Neuritic outgrowth was labeled with antibodies against neurofilaments and tubulin and screened by confocal laser scanning microscopy. Moreover, Western blot analysis was performed with antibodies to neuronal cell adhesion molecule (NCAM), L1, pan-cadherin, semaphorin-3F, as well as various ephrins.

RESULTS

The basement membrane and the stromal surface promoted the outgrowth of an extensive neuritic network, whereas the epithelial surface did not. Interestingly, these differences of neuritic growth were evident in cell cultures treated with serum-free medium lacking neurotrophic factors and in standard medium containing neurotrophic factors. Western blot analysis revealed an abundant expression of ephrin A4 in intact AM but not in epithelium-denuded AM, and no significant difference of pan-cadherin and NCAM expression was found in intact AM compared with denuded AM. Additionally, no expression of L1, semaphorin-3F, and the ephrins A1, A2, B1, and B3 was detected.

CONCLUSIONS

This study shows that AM exhibits location-dependent neuritic growth-promoting effects that might influence the clinical outcome of (amniotic membrane transplantation) in neurotrophic conditions.

The influence of various storage conditions on cell viability in amniotic membrane

Up to now freeze-dried, gamma-sterilised or glycerol-preserved amniotic membranes (AMs) have widely been used in the field of ophthalmology and wound care (e.g. leg ulcers, burns). After some preservation processes in use, like freeze-drying or glycerol-preserving, the cells in the AM are no longer viable. Within this study we evaluated the influence of different short-term and long-term storage conditions on cell viability in AM. Therefore AMs from cesarean section placentae were washed and biopsied to evaluate the microbiological status and to determine the viability of the tissue. Additionally, viability under various storage conditions was examined by assessment of mitochondrial activity. Preservation included temperatures above and below 0 degrees C as well as various media compositions. As expected, cell viability in amnion decreases during storage, in fact the effect was more pronounced when stored frozen, but the higher viability of amnion obtained by storage above 0 degrees C with medium is associated with the limitation to a short period of storage of about 28 days. The evaluated preservation methods are the basis for future non-clinical in-vivo studies in which the possible benefit of amnion as a viable biomaterial in wound healing will be investigated.

Inflammatory processes in preterm and term parturition

A role for the pro-inflammatory cytokines interleukin (IL)-1beta, IL-6, IL-8 and tumor necrosis factor alpha (TNF-alpha) is evident in term and preterm delivery, and this is independent of the presence of infection. All uterine tissues progress through a staged transformation near the end of pregnancy that leads from relative uterine quiescence and maintenance of pregnancy to the activation of the uterus that prepares it for the work of labour and production of stimulatory molecules that trigger the onset of labour and delivery. The uterus is activated by pro-inflammatory cytokines through stimulation of the expression and production of uterine activation proteins (UAPs). One of these actions is the stimulation of prostaglandin (PG) synthesis. Particularly important for labour is PGF(2alpha) and its receptor, PTGFR. In addition, pro-inflammatory cytokines are able to increase the synthesis of matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF) and the progesterone receptor C isoform, which leads to decreased tissue progesterone responsiveness. Some of these effects are replicated by PGF(2alpha), suggesting that it may act via its receptor to amplify the direct actions of cytokines. In turn, VEGF may enhance leukocyte recruitment to the uterus, and MMP-9 may promote activation of inactive pro-form cytokines. Pro-inflammatory cytokines also decrease the activity of 11beta-hydroxysteroid dehydrogenase, which likely increases intrauterine cortisol concentrations. In turn, cortisol may drive PG synthesis. Together these feed-forward mechanisms activate the uterus, trigger the production of uterine contractile stimulants and lead to labour and delivery.

Angiogenesis gene expression in mouse uterus during the common pathway of parturition

OBJECTIVE

The objective of the study was to investigate changes in the expression of angiogenesis-related genes during the common terminal pathway of parturition including spontaneous labor at term, as well as preterm labor (PTL), induced by either bacteria or ovariectomy.

STUDY DESIGN

Preterm pregnant mice (14.5 days of gestation) were treated with the following: (1) intrauterine injection of media; (2) intrauterine injection of heat-inactivated Escherichia coli; (3) ovariectomy; and (4) sham operation. Tissues from mice at term (19.5 days of gestation) were collected at term not in labor, term in labor, and 12 hours postpartum. Angiogenesis-related gene expression levels were quantitated by the measurement of specific mRNAs in uterine tissue by RT-qPCR and analyzed by repeated-measures analysis of variance.

RESULTS

The following results were found: (1) microarray analysis of the uterine transcriptome indicated an enrichment for the gene ontology category of angiogenesis in bacteria-induced PTL samples (P < or = .093); (2) several genes related to angiogenesis demonstrated significantly increased expression in samples in either term spontaneous labor or preterm labor; and (3) qRT-PCR measurements demonstrated that spontaneous term labor and preterm labor induced by either bacteria or ovariectomy all substantially increased the expression of multiple angiogenesis-related genes (P < or = .0003; Angpt2, Ctgf, Cyr61, Dscr1, Pgf, Serpine1, Thbs1, and Wisp 1).

CONCLUSION

Spontaneous labor at term, as well as pathologically induced preterm labor, all result in greatly increased expression of angiogenesis-related genes in the uterus.

Unexplained fetal death: another anti-angiogenic state

BACKGROUND

Pregnancy creates a unique situation in which both vasculogenesis and extensive angiogenesis are required for successful fetal and placental development. Recently, the soluble form of vascular endothelial growth factor (VEGF) receptor-1 (sVEGFR-1), an antagonist to VEGF and placental growth factor (PlGF) (two important angiogenic factors), has been implicated in the pathophysiology of preeclampsia and small for gestational age (SGA) without preeclampsia. There is, however, a paucity of information concerning plasma sVEGFR-1 concentrations in other obstetrical disorders. The purpose of this study was to determine plasma sVEGFR-1 concentrations in normal pregnancy, term gestation in labor, and in patients with pregnancy complications including spontaneous preterm labor, preterm premature rupture of the membranes (PROM), fetal death, and acute pyelonephritis.

METHODS

A cross-sectional study was conducted to determine the concentrations of sVEGFR-1 in plasma obtained from 499 women in the following groups: (1) non-pregnant women (n = 40); (2) pregnant women (n = 135); (3) normal pregnant women at term in labor (n = 60); (4) fetal death (n = 60); (5) spontaneous preterm labor with intact membranes (n = 102); (6) preterm PROM (n = 64); and (7) pregnancy with acute pyelonephritis (n = 38). Since plasma sVEGFR-1 concentration changes with gestational age, the difference between the actual and the expected plasma sVEGFR-1 concentration (derived from regression equation of normal pregnancy) for each patient (delta value) was calculated and used to examine the differences of plasma sVEGFR-1 concentrations among various groups. Plasma concentrations of sVEGFR-1 were determined by enzyme-linked immunoassay. Regression analysis and non-parametric statistics were used for analysis.

RESULTS

(1) Normal pregnant women before term had a median plasma sVEGFR-1 concentration significantly higher than non-pregnant women (p < 0.001); (2) plasma sVEGFR-1 concentration increased with advancing gestational age in normal pregnancy (r = 0.5; p < 0.001); (3) there was no significant difference in the median delta plasma concentration of sVEGFR-1 between normal pregnant women at term with and without labor (p = 0.09); (4) patients with fetal death had a median delta plasma concentration of sVEGFR-1 significantly higher than normal pregnant women (p = 0.001). Among patients with fetal death, those with unexplained causes (p = 0.04) and those with preeclampsia (p < 0.001) had a significantly higher delta plasma sVEGFR-1 concentration than normal pregnant women; and (5) there was no significant difference in the median delta plasma sVEGFR-1 concentration between normal pregnancy and preterm labor with intact membranes, preterm PROM (regardless of the presence or absence of microbial invasion of the amniotic cavity), or acute pyelonephritis (all p > 0.05).

CONCLUSIONS

Plasma sVEGFR-1 concentration is increased in a subset of patients with fetal death, but does not change in term and preterm parturition, rupture of fetal membranes, or acute pyelonephritis.

Functional network analysis of the transcriptomes of mesenchymal stem cells derived from amniotic fluid, amniotic membrane, cord blood, and bone marrow

Using high-density oligonucleotide microarrays and functional network analyses, we examined whether MSCs derived from four different origins exhibited unique gene expression profiles individually and then compared the gene expression profiles of all MSCs with those of fetal organs. Our results indicated that within each group of MSCs from the same origin, the variability of the gene expression levels was smaller than that between groups of different origins. Functional genomic studies revealed the specific roles of MSCs from different origins. Our results suggest that amniotic fluid MSCs may initiate interactions with the uterus by upregulating oxytocin and thrombin receptors. Amniotic membrane MSCs may play a role in maintaining homeostasis of fluid and electrolytes by regulating the networks of endothelin, neprilysin, bradykinin receptors, and atrial natriuretic peptide. Cord blood MSCs may be involved in innate immune systems as the neonatal defense system against the earliest encountered pathogens. Adult bone marrow MSCs may be an important source not only of all blood lineages but also of bone formation. However, in spite of the different gene expression profiles seen in MSCs derived from different origins, a set of core gene expression profiles was preserved in these four kinds of MSCs. The core signature transcriptomes of all MSCs, when contrasted against those of fetal organs, included genes involved in the regulation of extracellular matrix and adhesion, transforming growth factor-beta receptor signaling, and the Wnt signaling pathways. Disclosure of potential conflicts of interest is found at the end of this article.

Functional genomics of the pregnant uterus: from expectations to reality, a compilation of studies in the myometrium

Background

Studies on the human myometrium have reported on different microarrays containing different sets of genes or ESTs. However each study profiled only a small number of patients due to various constraints. More profiling information would be an addition to our knowledge base of parturition.

Methods

We compiled from five human studies, transcriptional differences between the non pregnant myometrium (NP), preterm myometrium (PTNIL), term myometrium not in labor (TNIL) and term myometrium in labor (TIL). Software modules developed by the Draghici's group at Wayne State University (Detroit, MI, USA) were used to propose a hierarchical list of several KEGG pathways most likely adjusted to changes observed in microarray experiments.

Results

The differential expression of 118 genes could be dispatched in 14 main KEGG pathways that were the most representative of the changes seen in NP and PTNIL, versus TNIL or TIL. Despite the potential of multiple pitfalls inherent to the use of the microarray technology, gene module analysis of the myometrial transcriptome reveals the activation of precise signaling pathways, some of which may have been under evaluated.

Conclusion

The remodelling and maturation processes that the uterus undergoes in pregnancy appear clearly as phenomena which last during the full course of gestation. It is attested by the nature of the main signaling pathways represented, in the comparison of the PTNIL versus TNIL uterus. Comparatively, the onset of labor is a phenomenon which remains less well characterized by these methods of analysis, possibly because it is a phenomenon occurring in too short a window to have been grasped by the studies carried out up to now.

Human spontaneous labor without histologic chorioamnionitis is characterized by an acute inflammation gene expression signature

OBJECTIVE

The purpose of this study was to identify which biological processes may be involved in normal labor.

STUDY DESIGN

Transcriptional profiles for chorioamniotic membranes (n = 24) and blood (n = 20) were generated from patients at term with no labor (TNL) and in labor (TIL).

RESULTS

Expression of 197 transcripts (P < or = .02) differentiated TIL and TNL chorioamniotic membrane samples. Gene Ontology analysis indicated that TIL samples had increased expression of multiple chemokines and transcripts associated with neutrophil and monocyte recruitment. Microarray results were verified using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) with independent samples. Transcriptional profiles from blood RNA revealed no Gene Ontology category enrichment of discriminant probe sets.

CONCLUSION

Labor induces gene expression changes consistent with localized inflammation, despite the absence of histologically detectable inflammation.

Failure of decidual arteriolar remodeling in the CBA/J x DBA/2 murine model of recurrent pregnancy loss is linked to increased expression of tissue inhibitor of metalloproteinase 2 (TIMP-2)

OBJECTIVE

Uterine vascular remodeling at mid gestation includes the thinning of the vessel walls and, typically, an increase in lumen diameter. This study aimed to elucidate any differences in structural remodeling in normal murine pregnancies versus those differences that resulted from the crossing of CBA/J female mice by DBA/2 male mice, a combination that is known to exhibit recurrent resorption/pregnancy loss.

STUDY DESIGN

CBA/J female mice that were pregnant by DBA/2 male mice (abnormals) and DBA/2 female mice that were pregnant by CBA/J male mice (normals) were killed at mid gestation, which is a time when fetal resorption can be identified. Tissues were collected for permanent fixation and gene expression studies with complementary DNA macroarrays that were specific for extracellular matrix proteins. A 2-fold increase in expression or a 50% decline was considered significant. Expression changes were confirmed by real-time reverse transcriptase-polymerase chain reaction.

RESULTS

The vessel-to-lumen diameter ratios were found to be significantly greater for the CBA/J implantation sites (1.50 +/- 0.05 vs 1.22 +/- 0.02, respectively; P < .0001), which indicates a lack of vascular remodeling. There was also a trend towards smaller lumen diameters for the CBA/J vessels, but this was not statistically significant (78.2 +/- 4.4 microm vs 93.5 +/- 6.8 microm, respectively; P = .22). The mean coefficient of variation for lumen measurements was 0.8% and for vessel diameter was 0.3%. The ranges were 0 to 3.2% and 0 to 1.4%, respectively. Tissue inhibitor of metalloproteinase 2 expression was up-regulated in the placentas of the group with higher resorption rates when compared with normals. This was confirmed with reverse transcriptase-polymerase chain reaction, where abnormals exhibited 2.6-fold greater tissue inhibitor of metalloproteinase 2 protein quantities when compared with normal controls (P = .03).

CONCLUSION

The expansive vascular remodeling of decidual vessels that is characteristic of normal murine pregnancy is attenuated significantly in the CBA/J x DBA/2 mating combination, which is known for its tendency to recurrent fetal resorption. This has been correlated with a relative overexpression of tissue inhibitor of metalloproteinase 2 protein in placentas of this strain combination and compared with normals.

Gene Expression Profiling of Cervical Tissue During Physiological Cervical Effacement

OBJECTIVE

The softening and dilation of cervical tissue during parturition requires a rapid reorganization of extracellular matrix and cellular interactions. The purpose of this study was to gain insight into the complex transformational changes in gene expression that lead to cervical effacement.

METHODS

Cervical biopsies from effaced cervices of 10 women undergoing spontaneous vaginal delivery and from competent cervices of 10 women undergoing primary cesarean delivery were collected at 37-41 weeks of gestation and subjected to differential complementary DNA (cDNA) microarray analysis. Gene expression results were validated by real-time polymerase chain reaction (PCR).

RESULTS

In a cDNA array that enables the analysis of the differential gene expression of more than 600 genes, the messenger (m)RNA expression of 40 genes increased more than 2.5-fold during cervical ripening. The majority of these genes encode cytokines, transcription factors, and cell-matrix-associated proteins. The mRNA expression of 6 genes decreased to less than 0.5-fold. The remaining 556 genes were not significantly altered. Real-time PCR analysis performed for selected, highly up-regulated genes confirmed our cDNA array findings.

CONCLUSION

Complete cervical effacement is associated with a characteristic and profound alteration in the gene expression profile of cervical cells. We hypothesize that an understanding of the molecular events that accompany physiological cervical dilation is pivotal to an understanding of pathological conditions such as premature delivery and postterm pregnancy.

Association of −634G/C and 936C/T polymorphisms of the vascular endothelial growth factor with spontaneous preterm delivery

BACKGROUND

There is convincing evidence for a central role of vascular endothelial growth factor (VEGF) in fetal and placental angiogenesis. Our present study was undertaken to examine the possible relationship between two common functional VEGF gene polymorphisms (- 634G/C and 936C/T), linked with altered VEGF gene responsiveness, and spontaneous preterm delivery.

METHODS

Genomic DNA was extracted from whole blood from 54 women with preterm labor and 79 menopausal women with at least two term spontaneous labors. DNA samples were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Individuals with 936T/T or 936C/T genotype demonstrated a statistically significant association with preterm delivery compared with those sharing 936C/C genotype [P = 0.0009, risk factor 2.05, 95% confidence interval (CI) 1.37-3.06]. There were no significant associations between spontaneous preterm delivery and - 634 genotypes.

CONCLUSION

An association was demonstrated between the VEGF 936C/T polymorphism and deliveries before 37 weeks of gestation.

Strategy for elucidating differentially expressed genes in leiomyomata identified by microarray technology

OBJECTIVE

cDNA microarray technology identifies genes that are differentially expressed between tissues. Our previous study identified several genes that might contribute to the fibroid phenotype. We therefore sought to confirm genes involved in three distinct signal transduction pathways.

DESIGN

Evaluation of differential mRNA and protein expression of Dlk, Frizzled-2, and CD-24 in fibroids compared with adjacent myometrium. University hospital.

PATIENT(S)

Five women undergoing medically indicated hysterectomy for symptomatic fibroids.

INTERVENTION(S)

Microarray analysis of up to 33000 genes, reverse transcriptase-polymerase chain reaction (RT-PCR), real-time RT-PCR, Western blot, and immunohistochemistry.

MAIN OUTCOME MEASURE(S)

Expression of mRNA transcripts and protein in fibroid compared with myometrium.A more extensive microarray confirmed differential expression of Frizzled-2 and CD-24 but did not confirm Dlk overexpression. RT-PCR and real-time PCR demonstrated equivalent Dlk mRNA expression between fibroid and myometrium (ratio, 1.02), a slight Frizzled-2 overexpression (ratio, 2.09), and robust CD-24 overexpression in fibroids (ratio, 12.35). Western blot and immunohistochemistry confirmed Frizzled-2 overexpression, but did not confirm Dlk overexpression.

CONCLUSION(S)

Microarray technology is the first phase of tissue evaluation, but changes in gene expression must be confirmed. Confirmed genes can then be used to generate hypotheses testing their involvement in fibroid development.