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24 result(s) for "Nevo, Ori"
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Impact of Th-17 Cytokines on the Regulation of Transporters in Human Placental Explants
Activated T helper 17 (Th-17) cytokines play a role in the pathophysiology of autoimmune and infectious diseases. While these diseases affect many women of childbearing age, little is known about the effect of these cytokines on placental transporters. As several pro-inflammatory cytokines impact the expression of ABC and SLC placental transporters, we hypothesized that these transporters may be similarly altered by elevated levels of circulating Th-17 cytokines. Cultured term human villous explants were treated with IL-17A, IL-22, or IL-23, alone or in combination. Samples were analyzed using qRT-PCR and Western blotting. The mRNA expression of OATP2B1 was significantly downregulated in explants by all individual cytokines and combination treatments, while decreased protein expression was seen with IL-23 and combination (p < 0.01). Combination treatment decreased the mRNA expression of BCRP and OAT4 but increased that of OCT3 (p < 0.01). Decreased accumulation of the OATP substrate, cascade blue, was seen in IL-23-treated choriocarcinoma JAr cells (p < 0.01). Elevated Th-17 cytokines, which are seen in infectious and autoimmune diseases, affect the expression and activity of OATP2B1, as well as mRNA expression of placental BCRP, OAT4, and OCT3. This dysregulation could impact the fetal exposure to endogenous and exogenous substrates.
Attenuation of VEGFR-2 Expression by sFlt-1 and Low Oxygen in Human Placenta
Vascular endothelial growth factor receptor 2 (VEGFR-2), the primary receptor for VEGF, is crucial for normal endothelial function. sFlt-1, a truncated and soluble form of VEGFR-1 which binds and inhibits VEGF, is increased in preeclampsia and is positively regulated by low oxygen. Here, we investigated the effects of sFlt-1 and hypoxia on VEGFR-2 expression and signaling in the human placenta. VEGFR-2 transcript and protein levels were significantly decreased in preeclamptic placentae compared to controls (1.82 and 1.85 fold, respectively). An inverse correlation was observed for VEGFR-2 and sFlt-1 levels in both singleton and twin placentae from patients with preeclampsia. Immunofluorescence analyses revealed co-localization of VEGFR-2 and sFlt-1 in placental vasculature and co-immunoprecipitation analyses confirmed VEGFR-2 and sFlt-1 interaction only in preeclamptic placentae compared to age-matched controls. VEGFR-2 transcript and protein levels from explants cultured in 3% O2 were significantly decreased compared to those incubated at 20% O2 (5.9 and 12.47 fold, respectively). Also, VEGFR-2 transcript levels were significantly decreased in early first trimester placentae (low oxygen environment) compared to late first trimester placentae (2.05 fold). We next explored whether sFlt-1 directly affects VEGFR-2 expression. Treatment of first trimester placental explants with sFlt-1 resulted in significantly decreased levels of VEGFR-2 (2.03 fold) and downstream signaling proteins phospho-ERK (1.60 fold) and phospho-Akt (1.64 fold). Our findings show a novel hypoxia-induced and PE-related down-regulation of VEGFR-2 in the human placenta. sFlt-1, which is known to be increased in hypoxic conditions and PE, directly attenuates VEGFR-2 expression and signaling. A direct interaction between sFlt-1 and VEGFR-2 may represent an important mechanism in VEGFR-2 regulation, inhibition of VEGFR-2-mediated processes in placentation and a novel platform to examine the onset of preeclampsia.
Ceramide-Induced Lysosomal Biogenesis and Exocytosis in Early-Onset Preeclampsia Promotes Exosomal Release of SMPD1 Causing Endothelial Dysfunction
Aberrant ceramide build-up in preeclampsia, a serious disorder of pregnancy, causes exuberant autophagy-mediated trophoblast cell death. The significance of ceramide accumulation for lysosomal biogenesis in preeclampsia is unknown. Here we report that lysosome formation is markedly increased in trophoblast cells of early-onset preeclamptic placentae, in particular in syncytiotrophoblasts. This is accompanied by augmented levels of transcription factor EB (TFEB). In vitro and in vivo experiments demonstrate that ceramide increases TFEB expression and nuclear translocation and induces lysosomal formation and exocytosis. Further, we show that TFEB directly regulates the expression of lysosomal sphingomyelin phosphodiesterase (L-SMPD1) that degrades sphingomyelin to ceramide. In early-onset preeclampsia, ceramide-induced lysosomal exocytosis carries L-SMPD1 to the apical membrane of the syncytial epithelium, resulting in ceramide accumulation in lipid rafts and release of active L-SMPD1 via ceramide-enriched exosomes into the maternal circulation. The SMPD1-containing exosomes promote endothelial activation and impair endothelial tubule formation in vitro . Both exosome-induced processes are attenuated by SMPD1 inhibitors. These findings suggest that ceramide-induced lysosomal biogenesis and exocytosis in preeclamptic placentae contributes to maternal endothelial dysfunction, characteristic of this pathology.
Histological Characterization of Class I HLA Molecules in Whole Umbilical Cord Tissue Towards an Inexhaustible Graft Alternative for Reconstructive Surgery
Background: Limited graft availability is a constant clinical concern. Hence, the umbilical cord (UC) is an attractive alternative to autologous grafts. The UC is an inexhaustible tissue source, and its removal is harmless and part of standard of care after the birth of the baby. Minimal information exists regarding the immunological profile of a whole UC when it is considered to be used as a tissue graft. We aimed to characterize the localization and levels of class I human leukocyte antigens (HLAs) to understand the allogenicity of the UC. Additionally, HLA-E and HLA-G are putative immunosuppressive antigens that are abundant in placenta, but their profiles in UC whole tissue are unclear. Hypothesis: The UC as a whole expresses a relatively low but ubiquitous level of HLA-ABC and significant levels of HLA-G and HLA-E. Methods: Healthy patients with no known pregnancy-related complications were approached for informed consent. UCs at term and between 12 and 19 weeks were collected to compare HLA profiles by gestational age. Formalin-fixed paraffin-embedded tissues were sectioned to 5 µm and immunohistochemically stained with a pan-HLA-ABC, two HLA-G-specific, or an HLA-E-specific antibody. Results: HLA-ABC was consistently found present in UCs. HLA-ABC was most concentrated in the UC vessel walls and amniotic epithelium but more dispersed in the Wharton’s Jelly. HLA-E had a similar localization pattern to HLA-ABC in whole UC tissues at both gestational ages, but its protein level was lower. HLA-G localization and intensity were poor in all UC tissues analyzed, but additional analyses by Western immunoblot and mass spectrometry revealed a low level of HLA-G in the UC. Conclusion: The UC may address limitations of graft availability. Rather than the presence of HLA-G, the immunosuppressive properties of the UC are more likely due to the abundance of HLA-E and the interaction known to occur between HLA-E and HLA–ABC. The co-localization of HLA-E and HLA-ABC suggests that HLA-E is likely presenting HLA-ABC leader peptides to immune cells, which is known to have a primarily inhibitory effect.
Risk factors for obstetric anal sphincter injuries in twin deliveries: a retrospective review
Introduction and hypothesis Risk factors for obstetric anal sphincter injuries (OASIS) have been well-established in singleton pregnancies. Considering the unique characteristics of twin deliveries, our aim was to identify risk factors for OASIS that are specific to twins. Methods A retrospective study of all vaginal twin deliveries in a tertiary center between 2000 and 2014. Women who experienced OASIS (the OASIS group) were compared with those whose anal sphincter was intact (controls). Results Overall 717 women were eligible for the study, of whom 20 (2.8 %) experienced OASIS. Women in the OASIS group were more likely to be nulliparous (95.0 % vs 53.7 %, p  < 0.001) and were characterized by a higher gestational age at delivery (36.1 ± 2.5 vs 34.6 ± 3.3, p  = 0.04), a higher birth weight for both twin A and twin B (2,507 ± 540 g vs 2,254 ± 525 g, p  = 0.03, and 25,49 ± 420 g vs 2,232 ± 606 g, p  = 0.004 respectively), and a higher rate of episiotomy (40.0 % vs 14.2 %, p  = 0.001), instrumental delivery for twin A (80.0 % vs 13.5 %, p  < 0.001) or twin B (80.0 % vs 18.7 %, p  < 0.001), and inter-twin delivery interval of over 30 min (20.0 % vs 7.5 %, p  = 0.04). The only factor that remained significant on multivariate analysis was instrumental delivery: forceps delivery of twin A (OR = 8.8, 95 % CI 2.6–30.1), vacuum extraction of twin A (OR = 9.2, 95 % CI 2.6–34.6), and forceps delivery of twin B (OR = 15.4, 95 % CI 4.9–48.6). In women with certain combinations of risk factors the risk of OASIS was as high as 30 %. Conclusion The overall rate of OASIS in twins is low and instrumental delivery, especially by forceps, is a risk factor.
Neuroprotective Anti-Apoptosis Effect of Estrogens in Traumatic Brain Injury
Traumatic brain injury (TBI) is a leading cause of death and functional disability in western countries, affecting mostly young patients. Despite intense and sustained efforts deployed for the development of new therapeutic strategies, no clinical benefit has been shown by any of the investigated compounds. Increasing attention has been drawn during the past two decades to the neuroprotective effects of estrogens, although most of the available data relate to ischemic brain injury. The purpose of the present study was to investigate the potential neuroprotective value of estrogens in TBI as a therapeutic modality. For this purpose, a contusion was created in the parietal cortex by dynamic cortical deformation in two groups of 10 Sprague-Dawley male rats. Following the injury, treated animals received conjugated estrogens for 3 days, using a subcutaneously implanted osmotic pump. Animals were then sacrificed, and TUNEL, anti-active Caspase 3, bcl-2, and bax labeling were performed in paraffin-embedded brain sections, allowing for comparative and quantitative analysis. In estrogen-treated animals, there was a marked and significant reduction of apoptosis in comparison with non-treated animals. The reduction in TUNEL and active Caspase 3 staining was similar and close to 50%. Optical analysis of histological slides prepared by bcl-2 labeling showed a significant increase in bcl-2 expression in estrogen-treated animals compared to non-treated animals. On the contrary, bax expression was not influenced by hormonal treatment, and no difference could be noticed between the two groups. These results support the potential therapeutic value of estrogens in TBI and further clarify their mode of action.
Attenuation of VEGFR-2 Expression by sFlt-1 and Low Oxygen in Human Placenta: e81176
Vascular endothelial growth factor receptor 2 (VEGFR-2), the primary receptor for VEGF, is crucial for normal endothelial function. sFlt-1, a truncated and soluble form of VEGFR-1 which binds and inhibits VEGF, is increased in preeclampsia and is positively regulated by low oxygen. Here, we investigated the effects of sFlt-1 and hypoxia on VEGFR-2 expression and signaling in the human placenta. VEGFR-2 transcript and protein levels were significantly decreased in preeclamptic placentae compared to controls (1.82 and 1.85 fold, respectively). An inverse correlation was observed for VEGFR-2 and sFlt-1 levels in both singleton and twin placentae from patients with preeclampsia. Immunofluorescence analyses revealed co-localization of VEGFR-2 and sFlt-1 in placental vasculature and co-immunoprecipitation analyses confirmed VEGFR-2 and sFlt-1 interaction only in preeclamptic placentae compared to age-matched controls. VEGFR-2 transcript and protein levels from explants cultured in 3% O2 were significantly decreased compared to those incubated at 20% O2 (5.9 and 12.47 fold, respectively). Also, VEGFR-2 transcript levels were significantly decreased in early first trimester placentae (low oxygen environment) compared to late first trimester placentae (2.05 fold). We next explored whether sFlt-1 directly affects VEGFR-2 expression. Treatment of first trimester placental explants with sFlt-1 resulted in significantly decreased levels of VEGFR-2 (2.03 fold) and downstream signaling proteins phospho-ERK (1.60 fold) and phospho-Akt (1.64 fold). Our findings show a novel hypoxia-induced and PE-related down-regulation of VEGFR-2 in the human placenta. sFlt-1, which is known to be increased in hypoxic conditions and PE, directly attenuates VEGFR-2 expression and signaling. A direct interaction between sFlt-1 and VEGFR-2 may represent an important mechanism in VEGFR-2 regulation, inhibition of VEGFR-2-mediated processes in placentation and a novel platform to examine the onset of preeclampsia.
Endometrial Thickness- a Practical Prospective Marker for the Risk of Surgical Intervention after RU486 Induced Abortion
Background: Medical termination of pregnancy [TOP] during the early first trimester is commonly used. However, treatment failure which warrants surgical intervention occurs in small proportion of patients. Our objective was to examine the effectiveness and predictive value of sonographic measurement of endometrial thickness during a follow up visit after medical abortion as an accurate predictor of the necessity of curettage for completion of pregnancy termination. Methods: Women who opted for medical TOP where treated by single dose of RU486 followed by a single dose of misoprostol. Endometrial thickness was evaluated by transvaginal U.S. at 14 days after misoprostol tretament. The data was collected prospectively for this cohort study which includes all the women undergoing medical abortion in the first seven weeks of gestation. Results: In 34.7% of the patients the endometrial width was 11 mm on the follow-up visit. Surgical intervention was performed in 18% of these patients, for a failure rate of the medical termination of pregnancy [TOP] of 6.25%, as com- pared with no failure rate in those with endometrium 11 mm, P 0.001. In the patients where the endometrium was 11-12 mm on follow-up, the failure rate was 5%, and if 12 mm the failure was 5.9%. In cases where the endometrium was 12-13 mm the failure rate was 27.3%, and if 13 mm the failure was 18.9%. When the endometrium was 13-14 mm the failure rate was 10%, and when 14 mm the failure was 23.7%. Half of the 18 patients who had undergone dilatation and curettage [D&C] for completion of the TOP, had endometrium 14 mm, one to two weeks after the medical abortion. Conclusion: Measurement of endometrial width after medical TOP is beneficial in segregating patient to low or high risk for surgical treatment of retained product of conception [POC]. Using a cutoff of 11 mm during the follow-up visit after medical TOP, 18% of the patients may need dilatation and curettage to complete the pregnancy termination, and if it is 14 mm, half of them may need surgical intervention. There is no difference between 11 and 14 mm regarding the risk of surgical intervention after medical TOP.
Single-cell mapping of the thymic stroma identifies IL-25-producing tuft epithelial cells
T cell development and selection are coordinated in the thymus by a specialized niche of diverse stromal populations 1 – 3 . Although much progress has been made over the years in identifying the functions of the different cell types of the thymic stromal compartment, there is no comprehensive characterization of their diversity and heterogeneity. Here we combined massively parallel single-cell RNA-sequencing 4 , 5 , spatial mapping, chromatin profiling and gene targeting to characterize de novo the entire stromal compartment of the mouse thymus. We identified dozens of cell states, with thymic epithelial cells (TECs) showing the highest degree of heterogeneity. Our analysis highlights four major medullary TEC (mTEC I–IV) populations, with distinct molecular functions, epigenetic landscapes and lineage regulators. Specifically, mTEC IV constitutes a new and highly divergent TEC lineage with molecular characteristics of the gut chemosensory epithelial tuft cells. Mice deficient in Pou2f3 , a master regulator of tuft cells, have complete and specific depletion of mTEC IV cells, which results in increased levels of thymus-resident type-2 innate lymphoid cells. Overall, our study provides a comprehensive characterization of the thymic stroma and identifies a new tuft-like TEC population, which is critical for shaping the immune niche in the thymus. A comprehensive characterization of the thymic stroma identifies a tuft-cell-like thymic epithelial cell population that is critical for shaping the immune niche in the thymus.
Thymic mimetic cells function beyond self-tolerance
Development of immunocompetent T cells in the thymus is required for effective defence against all types of pathogens, including viruses, bacteria and fungi. To this end, T cells undergo a very strict educational program in the thymus, during which both non-functional and self-reactive T cell clones are eliminated by means of positive and negative selection 1 .Thymic epithelial cells (TECs) have an indispensable role in these processes, and previous studies have shown the notable heterogeneity of these cells 2 – 7 . Here, using multiomic analysis, we provide further insights into the functional and developmental diversity of TECs in mice, and reveal a detailed atlas of the TEC compartment according to cell transcriptional states and chromatin landscapes. Our analysis highlights unconventional TEC subsets that are similar to functionally well-defined parenchymal populations, including endocrine cells, microfold cells and myocytes. By focusing on the endocrine and microfold TEC populations, we show that endocrine TECs require Insm1 for their development and are crucial to maintaining thymus cellularity in a ghrelin-dependent manner; by contrast, microfold TECs require Spib for their development and are essential for the generation of thymic IgA + plasma cells. Collectively, our study reveals that medullary TECs have the potential to differentiate into various types of molecularly distinct and functionally defined cells, which not only contribute to the induction of central tolerance, but also regulate the homeostasis of other thymus-resident populations. Multiomic analyses of mouse thymic epithelial cells identify several unconventional subsets that are mimetics of various populations of terminally differentiated parenchymal cells and provide insights into their development, molecular features and function.