Laeverin Protein Expression in Normal and Preeclamptic Placentas using Tissue Microarray Analysis

This is the peer reviewed version of the following article: Nystad, M., Sitras, V.S., Nordbakken, C., Pedersen, M.I. & Acharya, G. (2018). Laeverin Protein Expression in Normal and Preeclamptic Placentas using Tissue Microarray Analysis. Acta Obstetricia et Gynecologica Scandinavica, 97(5), 536-544, which has been published in final form at https://doi.org/10.1111/aogs.13304. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Introduction - Laeverin is a placenta‐specific protein that is normally expressed in the plasma membrane of human trophoblasts. In previous studies, we showed higher expression levels of laeverin gene in preeclamptic compared with normal placentas and found that laeverin protein was ectopically expressed in the cytoplasm of the preeclamptic placentas. Our objective was to investigate laeverin protein expression in normal and preeclamptic placentas combining immunohistochemistry and immunofluorescence. Material and methods - Tissue microarray analysis of 72 placentas, obtained from 33 preeclamptic and 39 uncomplicated pregnancies, was performed. Laeverin was labeled with a specific antibody for immunohistochemistry and immunofluorescence studies. Results - Immunohistochemistry showed that laeverin was expressed in syncytiotrophoblasts, cytotrophoblasts and extravillous trophoblasts in all placentas examined. In preeclamptic placentas (n = 33) compared with normal placentas (n = 39), laeverin was expressed in the cell membrane in 21 (64%) vs. 21 (54%) samples (p = 0.726), in the cytoplasm in 3 (9%) vs. 2 (5%) samples (p = 0.795) and in both the cytoplasm and membrane in 9 (27%) vs. 16 (41%) samples (p = 0.0522). All placental samples that showed cytoplasmic expression of laeverin were obtained from women who delivered before 34 weeks of gestation (early‐onset preeclampsia). Further, immunofluorescence studies showed laeverin expression in the cytoplasm of six preeclamptic (three early‐onset and three late‐onset) and one normal placenta but did not reveal any simultaneous cell membrane and cytoplasmic expression of laeverin. Conclusion - Laeverin is expressed in all trophoblast cell types of normal and preeclamptic placentas. Expression pattern of laeverin in trophoblast cells is heterogeneous and not necessarily membrane‐bound

Chitosan-based delivery system enhances antimicrobial activity of chlorhexidine

Infected chronic skin wounds and other skin infections are increasingly putting pressure on the health care providers and patients. The pressure is especially concerning due to the rise of antimicrobial resistance and biofilm-producing bacteria that further impair treatment success. Therefore, innovative strategies for wound healing and bacterial eradication are urgently needed; utilization of materials with inherent biological properties could offer a potential solution. Chitosan is one of the most frequently used polymers in delivery systems. This bioactive polymer is often regarded as an attractive constituent in delivery systems due to its inherent antimicrobial, anti-inflammatory, anti-oxidative, and wound healing properties. However, lipid-based vesicles and liposomes are generally considered more suitable as delivery systems for skin due to their ability to interact with the skin structure and provide prolonged release, protect the antimicrobial compound, and allow high local concentrations at the infected site. To take advantage of the beneficial attributes of the lipid-based vesicles and chitosan, these components can be combined into chitosan-containing liposomes or chitosomes and chitosan-coated liposomes. These systems have previously been investigated for use in wound therapy; however, their potential in infected wounds is not fully investigated. In this study, we aimed to investigate whether both the chitosan-containing and chitosan-coated liposomes tailored for infected wounds could improve the antimicrobial activity of the membrane-active antimicrobial chlorhexidine, while assuring both the anti-inflammatory activity and cell compatibility. Chlorhexidine was incorporated into three different vesicles, namely plain (chitosan-free), chitosan-containing and chitosan-coated liposomes that were optimized for skin wounds. Their release profile, antimicrobial activities, anti-inflammatory properties, and cell compatibility were assessed in vitro. The vesicles comprising chitosan demonstrated slower release rate of chlorhexidine and high cell compatibility. Additionally, the inflammatory responses in murine macrophages treated with these vesicles were reduced by about 60% compared to non-treated cells. Finally, liposomes containing both chitosan and chlorhexidine demonstrated the strongest antibacterial effect against Staphylococcus aureus. Both chitosan-containing and chitosan-coated liposomes comprising chlorhexidine could serve as excellent platforms for the delivery of membrane-active antimicrobials to infected wounds as confirmed by improved antimicrobial performance of chlorhexidine

High-throughput spatial sensitive quantitative phase microscopy using low spatial and high temporal coherent illumination

High space-bandwidth product with high spatial phase sensitivity is indispensable for a single-shot quantitative phase microscopy (QPM) system. It opens avenue for widespread applications of QPM in the field of biomedical imaging. Temporally low coherence light sources are implemented to achieve high spatial phase sensitivity in QPM at the cost of either reduced temporal resolution or smaller field of view (FOV). In addition, such light sources have low photon degeneracy. On the contrary, high temporal coherence light sources like lasers are capable of exploiting the full FOV of the QPM systems at the expense of less spatial phase sensitivity. In the present work, we demonstrated that use of narrowband partially spatially coherent light source also called pseudo-thermal light source (PTLS) in QPM overcomes the limitations of conventional light sources. The performance of PTLS is compared with conventional light sources in terms of space bandwidth product, phase sensitivity and optical imaging quality. The capabilities of PTLS are demonstrated on both amplitude (USAF resolution chart) and phase (thin optical waveguide, height ~ 8 nm) objects. The spatial phase sensitivity of QPM using PTLS is measured to be equivalent to that for white light source and supports the FOV (18 times more) equivalent to that of laser light source. The high-speed capabilities of PTLS based QPM is demonstrated by imaging live sperm cells that is limited by the camera speed and large FOV is demonstrated by imaging histopathology human placenta tissue samples. Minimal invasive, high-throughput, spatially sensitive and single-shot QPM based on PTLS will enable wider penetration of QPM in life sciences and clinical applications

Changes and tracking of fruit, vegetables and sugar-sweetened beverages intake from 18 months to 7 years in the Norwegian mother and child cohort study

Background A few studies have investigated tracking of dietary patterns or nutrient intake in pre-school children, but no studies have been identified examining tracking of sugar-sweetened beverages (SSB), fruit and vegetable intakes in early childhood (1–7 year olds). The purpose of this study was to investigate changes and tracking of intakes of fruit, vegetables and SSB, and association between maternal education and dietary tracking, from 18 months to 7 years of age. Methods Longitudinal data from the nation-wide Norwegian Mother and Child Cohort Study, conducted by the Norwegian Institute of Public Health were used, including 9 025 children participating at three time points (18 months, 36 months and 7 years). Frequencies of fruit, vegetables and SSB were assessed by questionnaire. Slightly different questions were used at each time point to collect information about intake. Maternal education was categorized into ≤ 12 years, 13–16 years, ≥ 17 years. Cross-tabulation, Spearman’s rho and multinomial logistic regression were used for assessing change, tracking and differences by maternal education. Results Analyses by gender indicated largest changes for intake of fruit and SSB from age 18 months to 7 years. Fair to moderate tracking coefficients (Spearman’s rho = 0.23-0.46) for intake of fruit, vegetables and SSB were found and children assigned to low, medium and high frequency of consumption at 18 months continued to be in the same group at age 36 months and 7 years. Children of mothers with low education consumed fruit and vegetables less often and SSB more often compared to children of mothers with high education at 18 months of age. Children with higher educated mothers had lower odds for increasing fruit intake or decreasing SSB intake, compared to children with lower educated mothers showing a stable intake. Conclusions The tracking coefficients for intakes were fair to moderate and differences in intakes according to maternal education were found already at age 18 months. This suggests that promotion of healthy dietary behaviours at an early age is important to prevent unfavourable dietary behaviours later in childhood. Moreover, it seems important to target mothers in nutrition interventions for improving dietary habits among children

Maternal serum laeverin (aminopeptidase Q) measured in the first trimester of pregnancy does not predict preeclampsia

Objective: The aim of this study was to compare the laeverin level in maternal serum from first trimester (11–14 weeks) of pregnancy between normal pregnancies and pregnancies that later developed preeclampsia (PE). Material and methods: This was a case-cohort study. The laeverin concentration was measured in cases with preterm PE (n = 55), term PE (n = 95), and a reference group of randomly selected women with normal pregnancy outcome (n = 200) in stored serum samples collected from the double-test as part of the combined first trimester trisomy 21 screening program. The samples were thawed and analyzed for laeverin. The median gestational age at blood sampling was 77 days (range 57–96 days). Multiple regression analysis was performed to establish a normal median. Concentrations were converted to multiples of the median (MoM) and groups were compared using the Mann–Whitney U-test. Results: In the reference group, laeverin was significantly correlated with gestational age (r = 0.18, p = .01) and its concentration ranged from 41–393 µg/L. No significant differences in the median laeverin MoM were found between the reference group (1.01 MoM) and cases with preterm PE (0.98 MoM) or term PE (0.96 MoM). Conclusions: First trimester maternal serum laeverin level cannot be used to predict preeclampsia

Human cytomegalovirus (HCMV) and hearing impairment: Infection of fibroblast cells with HCMV induces chromosome breaks at 1q23.3, between loci DFNA7 and DFNA49—Both involved in dominantly inherited, sensorineural, hearing impairment

Human cytomegalovirus (HCMV) infection is the most common congenital infection in developed countries and is responsible for a substantial fraction of sensorineural hearing impairment (SNHI) in children. The risk of hearing impairment is associated with viral load in urine and blood collected during the first postnatal month. However, although inner ear abnormalities are observed in some children with HCMV-induced SNHI, the exact mechanism whereby congenital HCMV infection causes hearing impairment is unknown. Earlier studies using standard cytogenetic mapping techniques showed that infection of S-phase human fibroblast cells with HCMV resulted in two specific, site-directed, chromosome breaks at band positions 1q21 and 1q42 which include loci involved in dominantly and recessively inherited hearing impairment, respectively. These findings suggested that cells infected with HCMV might provide a reservoir for genetic damage and, in a clinical perspective, a scenario could be envisioned whereby hearing impairment could result from early DNA damage of dividing fetal cells rather than viral replication and cell lysis. In this work we demonstrate, using fine mapping techniques, that HCMV infection in S-phase fibroblast cells induces genetic damage at 1q23.3, within a maximal region of 37 kb, containing five low copy repeat (LCR) elements. The breakpoint is situated between two hearing impairment (HI) loci, DFNA49 and DFNA7, and in close proximity to the MPZ gene previously shown to be involved in autosomal dominant Charcot-Marie-Tooth syndrome (CMT1B) with auditory neuropathy

Following the fate of dye-containing liposomes in vitro

The rather limited success of translation from basic research to clinical application has been highlighted as a major issue in the nanomedicine field. To identify the factors influencing the applicability of nanosystems as drug carriers and potential nanomedicine, we focused on following their fate through fluorescence-based assays, namely flow cytometry and imaging. These methods are often used to follow the nanocarrier internalization and targeting; however, the validity of the obtained results strictly depends on how much the nanosystem’s fate can be inferred from the fate of fluorescent dyes. To evaluate the parameters that affect the physicochemical and biological stability of the labeled nanosystems, we studied the versatility of two lipid dyes, TopFluor®-PC and Cy5-DSPE, in conventional liposomes utilizing well-defined in vitro assays. Our results suggest that the dye can affect the major characteristics of the system, such as vesicle size and zeta-potential. However, a nanocarrier can also affect the dye properties. Medium, temperature, time, fluorophore localization and its concentration, as well as their interplay, affect the outcome of tracing experiments. Therefore, an in-depth characterization of the labeled nanosystem should be fundamental to understand the conditions that validate the results within the screening process in optimization of nanocarrier

Longitudinal reference ranges for maternal plasma laeverin, and its role as a potential biomarker of preeclampsia

Background Laeverin is a placenta-specific membrane-bound aminopeptidase. In this study we wanted to: 1) serially measure plasma levels of laeverin in healthy women during the second half of pregnancy and postpartum, 2) determine whether laeverin is differently expressed at 22–24 weeks in women who later develop preeclampsia compared to controls, 3) compare laeverin protein expression in placenta and umbilical vein serum in healthy and preeclamptic pregnancies at birth. Methods Plasma was obtained serially, approximately every 4-weeks, from 53 healthy women with uncomplicated pregnancies during 22+0 to 39+6 weeks of gestation, and at 22–24 weeks from 15 women who later developed preeclampsia. Enzyme-linked immunosorbent assay was used to measure laeverin protein concentration. Serum from healthy non-pregnant premenopausal women (n = 10), menopausal women (n = 10) and men (n = 11) were used as negative controls. Protein extracts from placental tissue were obtained after birth from healthy- (n = 11) and preeclamptic women (n = 13). Paired umbilical artery and vein serum samples from the neonates (n = 10) of healthy mothers were also analyzed. Multilevel modeling was used to determine the reference centiles. Differences between groups were analyzed using Student’s t-test. Results Healthy pregnant women at term (37–40 weeks) had significantly higher plasma levels of laeverin (mean 4.95 ± 0.32 ng/mL; p < 0.0001) compared to men (mean 0.18 ± 0.31 ng/mL), non-pregnant premenopausal women (mean 0.77 ± 0.26 ng/mL) and postmenopausal women (mean 0.57 ± 0.40 ng/mL). Maternal plasma laeverin levels decreased with advancing gestation, from 6.96 ± 0.32 ng/mL at 22–24 weeks to 4.95 ± 0.32 ng/mL at term (p < 0.0001) in uncomplicated pregnancies. Half of the women who developed preeclampsia had plasma laeverin levels below the 5th percentile at 22–24 weeks gestation. However, laeverin levels were 1.6 fold higher in preeclamptic compared to healthy placentas (p = 0.0071). Umbilical venous samples of healthy neonates (n = 38) had higher (p = 0.001) mean levels of laeverin (16.63 ± 0.73 ng/mL), compared to neonates of preeclamptic (n = 14) mothers (12.02 ± 1.00 ng/mL). Postpartum plasma levels of laeverin decreased in healthy and preeclamptic women with a half-life of 3 and 5 days, respectively. Conclusions Maternal plasma levels of laeverin decrease with advancing gestation during the second half of normal pregnancy and lower levels measured at 22–24 weeks might be associated with the development of preeclampsia later in gestation