Placenta-targeted treatment strategies: An opportunity to impact fetal development and improve offspring health later in life

Placental targeted drug delivery: a review of recent progress

The placenta plays a crucial role in mediating nutrient and gas exchange between the mother and fetus during pregnancy. Targeting therapeutic agents to the placenta presents significant opportunities for treating placental disorders and enhancing fetal outcomes. However, the unique structural complexity and selective permeability of the placenta pose substantial challenges for effective drug delivery. This review provides a comprehensive overview of current strategies for placental targeting, including lipid nanoparticle (LNP) delivery systems, targeted peptide modifications, specific antibody targeting of placental receptors, and the use of viral vectors. We critically analyze the advantages and limitations of each approach, emphasizing recent advancements in enhancing targeting specificity and delivery efficiency. By consolidating the latest research developments, this review aims to foster further innovation in placental drug delivery methods and contribute significantly to the advancement of therapeutic strategies for placental disorders, ultimately improving outcomes for both mother and fetus.

Transfer of Antioxidant Capacity Through Placenta and Colostrum: β-Carotene and Superoxide Dismutase Collaboratively Enhance Integrated Breeding of Sows and Piglets

Sows and piglets face heightened oxidative stress during gestation and lactation, yet strategies to simultaneously mitigate these challenges remain underexplored. This study investigated the effects of β-carotene and superoxide dismutase (SOD) supplementation on 140 Landrace × Yorkshire sows (parity 3-5) randomly assigned to (1) a control; (2) long-term low-dose treatment (25 mg/kg β-carotene, 4 mg/kg SOD, or both) throughout gestation-lactation; or (3) short-term high-dose treatment (100 mg/kg β-carotene, 14 mg/kg SOD, or both) administered 7 days pre/post-weaning and farrowing. Our data indicate that the antioxidants enhanced the productive performance of both sows and piglets, with the most pronounced effect observed in the long-term, low-dose combined administration of β-carotene and SOD. The composite antioxidants significantly improved the systemic antioxidant capacity in sows, while concurrently reducing the cortisol and lipopolysaccharide concentrations in the serum. This enhancement contributed to elevations in serum progesterone and prolactin levels at day 40 of gestation and farrowing, respectively, ultimately increasing the number of weaned piglets and decreasing the backfat loss. In addition, the compound antioxidants improved the serum antioxidant indices of piglets, increased the growth hormone concentrations, and improved the litter weight gain. Mechanistically, the placental upregulation of CAT, GPX1, and GLUT3, alongside Claudin1, Occludin, and ZO-1 expression, underpinned improved nutrient transport and barrier function. These findings demonstrate that β-carotene and SOD synergistically transfer antioxidant capacity via placental and colostrum pathways, offering a viable strategy for integrated sow-piglet management.

Maternal Hypertension Aggravates Vascular Dysfunction After Injury in Male Adult Offspring Through Transgenerational Transmission of N6-Methyladenosine

BACKGROUND

Whether maternal hypertension contributes to the enhanced susceptibility to vascular remodeling in adult offspring through epigenetic mechanisms remains unclear. We aimed to address this gap in the literature using a transgenerational mouse model.

METHODS

Gestational hypertension was induced in pregnant mice using chronic angiotensin II infusion. Blood pressure was monitored using the tail-cuff method. Two months post-delivery, an N6-methyladenosine epitranscriptomic microarray analysis was performed on the carotid arteries of second-generation mice. A unilateral carotid artery injury model was used to study the postinjury vascular response in vivo. Furthermore, carotid ultrasonography, immunohistochemistry, and molecular biological parameters were assessed in adult offspring.

RESULTS

Exposure to maternal hypertension decreased the birth weight of live pups and increased the fetal death rate. Compared with normal offspring, adult offspring with hypertension had wire-induced injury that led to greater vascular remodeling, which was associated with aggravated inflammation imbalance, fibrosis, and oxidative stress. In addition, aberrant N6-methyladenosine methylation, increased N6-methyladenosine levels, and increased METTL3 (methyltransferase-like 3) expression were detected in the vessels of offspring with hypertension. Maternal METTL3 deficiency increased the birth weight of live pups with hypertension, improved vascular dysfunction, and alleviated vascular inflammation in adult offspring with hypertension after injury.

CONCLUSIONS

Maternal hypertension can induce transgenerational transmission of enhanced susceptibility to vascular remodeling, and the possible underlying mechanism is associated with altered METTL3-mediated N6-methyladenosine methylation. Therefore, this study reveals the role of epigenetic effects across generations and provides new insights into vascular remodeling causes.

Does preeclampsia impact the gut microbiota of preterm offspring during early infancy?

Preeclampsia (PE) is a pregnancy complication characterized by high blood pressure and organ damage. This study investigates the differences in the gut microbiota between preterm neonates born to mothers with PE and those born to mothers without PE (PR), aiming to understand how maternal health conditions like PE influence neonatal gut microbiota. The early gut microbiota plays a crucial role in neonatal health, and disturbances in its development can have long-term consequences. Fecal samples were collected from preterm neonates of PE and PR mothers at 2 and 6 weeks postpartum and analyzed using shotgun metagenomic sequencing. We found that PE significantly affected the gut microbial composition of preterm neonates, particularly at 2 weeks postpartum. The gut microbial diversity in the PE_2 group was notably lower compared to the PR_2 group, with no significant difference observed between the PR_6 and PE_6 groups. At the phylum level, Firmicutes and Proteobacteria were predominant, with significant differences observed, particularly a lower abundance of Actinobacteria in the PE_2 group. At the genus level, Escherichia, Enterococcus, and Klebsiella were more prevalent in the PE_2 group, whereas Bifidobacterium and Cutibacterium dominated the PR_2 group. The gut virome analysis showed no significant differences among the groups. Functional analysis revealed distinct metabolic pathway activities across the groups, suggesting that early disturbances due to PE impact the establishment of healthy gut microbiota. These findings underscore the substantial influence of maternal health on the early development of the neonatal gut microbiota and highlight the potential long-term health consequences. Additionally, the differences in metabolic pathways further emphasize the impact of preeclampsia on gut microbiota functionality.

Effects of in ovo feeding of vitamin C on embryonic development, hatching process, and chick rectal temperature of broiler embryos

Maternal nutritional status plays a crucial role in embryonic development and has persistent effects on postnatal chicks. Vitamin C (VC) plays an important role in embryonic and postnatal development involved in nutri-epigenetics. The present study was conducted to investigate the effects of in ovo feeding (IOF) of VC on embryonic development, egg hatching time, and chick rectal temperature. Trial 1 was conducted under normal incubation conditions without the IOF procedure and was designed to analyze the characteristics of embryonic development and establish the scoring standards for yolk absorption and the rupture of the shell membrane. The results showed that the relative weight of the embryo and residual yolk and the organ indexes were reliable indicators of embryonic development. Yolk absorption was scored 0, 1, 2, 3, and 4, with a higher score indicating more complete absorption. In addition, the rupture of the shell membrane was divided into two cases: YES and NO. Trial 2 included three groups, control (CON), normal saline (NS), and vitamin C (VC), and was designed to detect the effects of IOF of VC on the indicators in trial 1, as well as the plasma biochemical indicators. At embryonic age 11 (E11), each egg in the CON group was non-injected, each egg in the NS group was injected with 0.1 mL of sterile normal saline, and each egg in the VC group was injected with 0.1 mL of sterile normal saline containing 3 mg vitamin C. The whole day of E21 was evenly divided into three time periods: early (incubation hours 480-488), middle (incubation hours 488-496), and late (incubation hours 496-504). Among the CON, NS, and VC groups, the percentages of the early-hatched chicks (egg hatching time) were 29.31, 12.00, and 33.90%, respectively. The proportions of early and middle hatched chicks in these groups were 51.72, 42.00, and 38.27%, respectively. The rectal temperature of chicks was lower (p < 0.05) in the VC group than in the CON and NS groups. Compared to the NS group, the plasma biochemical indicators in the VC group showed significantly lower levels of alkaline phosphatase (ALP), total protein (TP), albumin (ALB), GLB, total bilirubin (TBIL), TBA, uric acid (UA), high-density lipoprotein cholesterol (HDL-C), and corticosterone (CORT) (p < 0.05). Additionally, alanine aminotransferase (ALT) had an increasing trend (p = 0.059) in the VC group. In conclusion, our data demonstrated that VC accelerated the hatching process and reduced chicks' rectal temperature, which may be related to the improvement of liver function and changes in metabolism, as indicated by blood biochemical indicators.

The rebalancing of the immune system at the maternal-fetal interface ameliorates autism-like behavior in adult offspring

Maternal immune activation (MIA) is critical for imparting neuropathology and altered behaviors in offspring; however, maternal-fetal immune cell populations have not been thoroughly investigated in MIA-induced autism spectrum disorders (ASDs). Here, we report the single-cell transcriptional landscape of placental cells in both PBS- and poly(I:C)-induced MIA dams. We observed a decrease in regulatory T (Treg) cells but an increase in the M1 macrophage population at the maternal-fetal interface in MIA dams. Based on the Treg-targeting approach, we investigate an immunoregulatory protein, the helminth-derived heat shock protein 90α (Sjp90α), that induces maternal Treg cells and subsequently rescues the autism-like behaviors in adult offspring. Furthermore, in vivo depletion of maternal macrophages attenuates placental inflammatory reaction and reverses behavioral abnormalities in adult offspring. Notably, Sjp90α induces CD4+ T cell differentiation via scavenger receptor A (SR-A) on the macrophage in vitro. Our findings suggest a maternal Treg-targeted approach to alleviate MIA-induced autism-like behavior in adult offspring.

Placental Gene Therapy for Fetal Growth Restriction and Preeclampsia: Preclinical Studies and Prospects for Clinical Application

In the last three decades, gene therapy has demonstrated significant progress. Over 700 active investigational new drug (IND) applications have been reported. Research on in utero gene therapy has advanced, but ethical and safety concerns persist. A novel approach under investigation is placental gene therapy, which holds promise for targeting diseases associated with placental dysfunction, such as fetal growth restriction (FGR) and preeclampsia. One of the underlying causes of placental insufficiency in these conditions is reduced placental growth factor-driven angiogenesis and endothelial cell dysfunction during fetal development. Studies have explored the overexpression of growth factor transgenes like IGF-1 to address FGR, yielding promising outcomes in animal models. Furthermore, intra-placental gene transfer, instead of systemic delivery of gene therapy vectors, has the potential to treat and cure these disorders. However, challenges and limitations akin to in utero gene therapy persist, including the risk of in utero infection, potential impairment of the mother's future fertility, the risk of germline integration, and possible off-target effects of gene transfer in the fetus or the mother. Consequently, additional research and deliberation within the scientific and medical communities are warranted to fully comprehend the potential benefits and risks of placental gene therapy.

Preeclampsia: A comprehensive review

Preeclampsia (PE) is a life-threatening disease of pregnancy and a prominent cause of neonatal and maternal mortality and morbidity. PE affects approximately 5-10% of pregnancies worldwide, posing significant risks to perinatal and maternal health. It is characterized by a variety of interconnected pathological cascades contributing to the stimulation of intravascular inflammation, oxidative stress (OS), endothelial cell activation, and syncytiotrophoblast stress that converge on a common pathway, ultimately resulting in disease progression. The present study was designed and executed to review the existing scientific literature, specifically focusing on the etiology (gestational diabetes mellitus and maternal obesity, insulin resistance, metabolic syndrome, maternal infection, periodontal disease, altered microbiome, and genetics), clinical presentations (hypertension, blood disorders, proteinuria, hepatic dysfunction, renal dysfunction, pulmonary edema, cardiac dysfunction, fetal growth restrictions, and eclampsia), therapeutic clinical biomarkers (creatinine, albuminuria, and cystatin C) along with their associations and mechanisms in PE. In addition, this study provides insights into the potential of nanomedicines for targeting these mechanisms for PE management and treatment. Inflammation, OS, proteinuria, and an altered microbiome are prominent biomarkers associated with progression and PE-related pathogenesis. Understanding the molecular mechanisms, exploring suitable markers, targeted interventions, comprehensive screening, and holistic strategies are critical to decreasing the incidence of PE and promoting maternal-fetal well-being. The present study comprehensively reviewed the etiology, clinical presentations, therapeutic biomarkers, and preventive potential of nanomedicines in the treatment and management of PE.

Placenta-targeted Treatment Strategies for Preeclampsia and Fetal Growth Restriction: An Opportunity and Major Challenge

The placenta plays a crucial role in maintaining normal pregnancy. The failure of spiral artery remodeling (SAR) is a key factor leading to placental ischemia and poor perfusion which is strongly associated with obstetric diseases, including preeclampsia (PE) and fetal growth restriction (FGR). Existing interventions for PE and FGR are limited and termination of pregnancy is inevitable when the maternal or fetus condition deteriorates. Considering the safety of the mother and fetus, treatments that may penetrate the placental barrier and harm the fetus are not accepted. Developing targeted treatment strategies for these conditions is urgent and necessary. With the proven efficacy of targeted therapy in treating conditions such as endometrial cancer and trophoblastic tumors, research on placental dysfunction continues to deepen. This article reviews the studies on placenta-targeted treatment and drug delivery strategies, summarizes the characteristics proposes corresponding improvement measures in targeted treatment, provides solutions for existing problems, and makes suggestions for future studies.

Guidelines for in vivo models of developmental programming of cardiovascular disease risk

Research using animals depends on the generation of offspring for use in experiments or for the maintenance of animal colonies. Although not considered by all, several different factors preceding and during pregnancy, as well as during lactation, can program various characteristics in the offspring. Here, we present the most common models of developmental programming of cardiovascular outcomes, important considerations for study design, and provide guidelines for producing and reporting rigorous and reproducible cardiovascular studies in offspring exposed to normal conditions or developmental insult. These guidelines provide considerations for the selection of the appropriate animal model and factors that should be reported to increase rigor and reproducibility while ensuring transparent reporting of methods and results.

Association of Placental Pathology with Physical and Neuronal Development of Infants: A Narrative Review and Reclassification of the Literature by the Consensus Statement of the Amsterdam Placental Workshop Group

The placenta is the largest fetal organ, which connects the mother to the fetus and supports most aspects of organogenesis through the transport of nutrients and gases. However, further studies are needed to assess placental pathology as a reliable predictor of long-term physical growth or neural development in newborns. The Consensus Statement of the Amsterdam Placental Workshop Group (APWGCS) on the sampling and definition of placental lesions has resulted in diagnostic uniformity in describing the most common pathological lesions of the placenta and contributed to the international standardization of descriptions of placental pathology. In this narrative review, we reclassified descriptions of placental pathology from previously published papers according to the APWGCS criteria and comparatively assessed the relationship with infantile physical and/or neural development. After reclassification and reevaluation, placental pathology of maternal vascular malperfusion, one of the APWGCS criteria, emerged as a promising candidate as a universal predictor of negative infantile neurodevelopmental outcomes, not only in term and preterm deliveries but also in high-risk groups of very low birthweight newborns. However, there are few studies that examined placental pathology according to the full categories of APWGCS and also included low-risk general infants. It is necessary to incorporate the assessment of placental pathology utilizing APWGCS in the design of future birth cohort studies as well as in follow-up investigations of high-risk infants.

Prenatal exposure to per- and polyfluoroalkyl substances and DNA methylation in the placenta: A prospective cohort study

Epidemiological studies regarding the relationship between per- and polyfluoroalkyl substances (PFAS) and DNA methylation were limited. We investigated the associations of maternal PFAS concentrations with placental DNA methylation and examined the mediating role of methylation changes between PFAS and infant development. We measured the concentrations of 11 PFAS in maternal plasma during early pregnancy and infant development at six months of age. We analyzed genome-wide DNA methylation in 16 placental samples using reduced representation bisulfite sequencing. Additionally, we measured DNA methylation levels using bisulfite amplicon sequencing in 345 mother-infant pairs for five candidate genes, including carbohydrate sulfotransferase 7 (CHST7), fibroblast growth factor 13 (FGF13), insulin receptor substrate 4 (IRS4), paired like homeobox 2Ap (PHOX2A), and plexin domain containing 1 (PLXDC1). We found that placental DNA methylation profiles related to PFOA mainly enriched in angiogenesis and neuronal signaling pathways. PFOA was associated with hypomethylation of IRS4 and PLXDC1, and PFNA was associated with PLXDC1 hypomethylation. There were positive associations of CHST7 methylation with PFTrDA and IRS4 methylation with PFDoA and PFTrDA. PLXDC1 hypomethylation mediated the association between PFOA and suspected developmental delay in infants. Future studies with larger sample sizes are warranted to confirm these findings.

Mechanistic insights into the development of severe fetal growth restriction

Fetal growth restriction (FGR), which most commonly results from suboptimal placental function, substantially increases risks for adverse perinatal and long-term outcomes. The only "treatment" that exists is delivery, which averts stillbirth but does not improve outcomes in survivors. Furthermore, the potential long-term consequences of FGR to the fetus, including cardiometabolic disorders, predispose these individuals to developing FGR in their future pregnancies. This creates a multi-generational cascade of adverse effects stemming from a single dysfunctional placenta, and understanding the mechanisms underlying placental-mediated FGR is critically important if we are to improve outcomes and overall health. The mechanisms behind FGR remain unknown. However, placental insufficiency derived from maldevelopment of the placental vascular systems is the most common etiology. To highlight important mechanistic interactions within the placenta, we focus on placental vascular development in the setting of FGR. We delve into fetoplacental angiogenesis, a robust and ongoing process in normal pregnancies that is impaired in severe FGR. We review cellular models of FGR, with special attention to fetoplacental angiogenesis, and we highlight novel integrin-extracellular matrix interactions that regulate placental angiogenesis in severe FGR. In total, this review focuses on key developmental processes, with specific focus on the human placenta, an underexplored area of research.

Placental Changes and Neuropsychological Development in Children-A Systematic Review

Placental dysfunction may increase the offspring's later-life disease risk. The objective of this systematic review was to describe associations between pathological placental changes and neuropsychological outcomes in children after the neonatal period. The inclusion criteria were human studies; original research; direct placental variables; neuropsychological outcomes; and analysis between their associations. The exclusion criterion was the offspring's age-0-28 days or >19 years. The MEDLINE and EMBASE databases were last searched in May 2022. We utilized the ROBINS-I for the risk of bias assessment and performed a narrative synthesis. In total, 3252 studies were identified, out of which 16 were included (i.e., a total of 15,862 participants). Half of the studies were performed on children with neonatal complications, and 75% of the studies reported an association between a placental change and an outcome; however, following the completion of the funnel plots, a risk of publication bias was indicated. The largest study described a small association between placental size and a risk of psychiatric symptoms in boys only. Inconsistency between the studies limited the evidence in this review. In general, no strong evidence was found for an association between pathological placental changes and childhood neuropsychological outcomes after the neonatal period. However, the association between placental size and mental health in boys indicates a placental sexual dimorphism, thereby suggesting an increased vulnerability for male fetuses.

A global view of hypertensive disorders and diabetes mellitus during pregnancy

Two important maternal cardiometabolic disorders (CMDs), hypertensive disorders in pregnancy (HDP) (including pre-eclampsia) and gestational diabetes mellitus (GDM), result in a large disease burden for pregnant individuals worldwide. A global consensus has not been reached about the diagnostic criteria for HDP and GDM, making it challenging to assess differences in their disease burden between countries and areas. However, both diseases show an unevenly distributed disease burden for regions with a low income or middle income, or low-income and middle-income countries (LMICs), or regions with lower sociodemographic and human development indexes. In addition to many common clinical, demographic and behavioural risk factors, the development and clinical consequences of maternal CMDs are substantially influenced by the social determinants of health, such as systemic marginalization. Although progress has been occurring in the early screening and management of HDP and GDM, the accuracy and long-term effects of such screening and management programmes are still under investigation. In addition to pharmacological therapies and lifestyle modifications at the individual level, a multilevel approach in conjunction with multisector partnership should be adopted to tackle the public health issues and health inequity resulting from maternal CMDs. The current COVID-19 pandemic has disrupted health service delivery, with women with maternal CMDs being particularly vulnerable to this public health crisis.

Nanoparticle-mediated transgene expression of insulin-like growth factor 1 in the growth restricted guinea pig placenta increases placenta nutrient transporter expression and fetal glucose concentrations

Fetal growth restriction (FGR) significantly contributes to neonatal and perinatal morbidity and mortality. Currently, there are no effective treatment options for FGR during pregnancy. We have developed a nanoparticle gene therapy targeting the placenta to increase expression of human insulin-like growth factor 1 (hIGF1) to correct fetal growth trajectories. Using the maternal nutrient restriction guinea pig model of FGR, an ultrasound-guided, intraplacental injection of nonviral, polymer-based hIGF1 nanoparticle containing plasmid with the hIGF1 gene and placenta-specific Cyp19a1 promotor was administered at mid-pregnancy. Sustained hIGF1 expression was confirmed in the placenta 5 days after treatment. Whilst increased hIGF1 did not change fetal weight, circulating fetal glucose concentration were 33%-67% higher. This was associated with increased expression of glucose and amino acid transporters in the placenta. Additionally, hIGF1 nanoparticle treatment increased the fetal capillary volume density in the placenta, and reduced interhaemal distance between maternal and fetal circulation. Overall, our findings, that trophoblast-specific increased expression of hIGF1 results in changes to glucose transporter expression and increases fetal glucose concentrations within a short time period, highlights the translational potential this treatment could have in correcting impaired placental nutrient transport in human pregnancies complicated by FGR.

Maternal hypertensive disorder of pregnancy and mortality in offspring from birth to young adulthood: national population based cohort study

OBJECTIVE

To examine the association of maternal hypertensive disorder of pregnancy (HDP) with overall and cause specific mortality in offspring from birth to young adulthood.

DESIGN

Nationwide population based cohort study.

SETTING

Danish national health registers.

PARTICIPANTS

All 2 437 718 individuals live born in Denmark, 1978-2018, with follow-up from date of birth until date of death, emigration, or 31 December 2018, whichever came first.

MAIN OUTCOME MEASURES

The primary outcome was all cause mortality. Secondary outcomes were 13 specific causes of death in offspring from birth to young adulthood (age 41 years). Cox regression was used to assess the association, taking into consideration several potential confounders. The role of timing of onset and severity of pre-eclampsia, maternal history of diabetes, and maternal education were also studied.

RESULTS

102 095 mothers had HDP: 67 683 with pre-eclampsia, 679 with eclampsia, and 33 733 with hypertension. During follow-up to 41 years (median 19.4 (interquartile range 9.7-28.7) years), deaths occurred in 781 (58.94 per 100 000 person years) offspring born to mothers with pre-eclampsia, 17 (133.73 per 100 000 person years) born to mothers with eclampsia, 223 (44.38 per 100 000 person years) born to mothers with hypertension, and 19 119 (41.99 per 100 000 person years) born to mothers with no HDP. The difference in cumulative incidence in overall mortality between cohorts exposed and unexposed to maternal HDP was 0.37% (95% confidence interval 0.11% to 0.64%), and the population attributable fraction for maternal HDP was estimated as 1.09% (95% confidence interval 0.77% to 1.41%). Maternal HDP was associated with a 26% (hazard ratio 1.26, 95% confidence interval 1.18 to 1.34) higher risk of all cause mortality in offspring. The corresponding estimates for maternal pre-eclampsia, eclampsia, and hypertension were 1.29 (1.20 to 1.38), 2.88 (1.79 to 4.63), and 1.12 (0.98 to 1.28). Increased risks were also observed for several cause specific mortalities, such as deaths from conditions originating in the perinatal period (2.04, 1.81 to 2.30), cardiovascular diseases (1.52, 1.08 to 2.13), digestive system diseases (2.09, 1.27 to 3.43), and endocrine, nutritional, and metabolic diseases (1.56, 1.08 to 2.27). The increased risks were more pronounced among offspring of mothers with early onset and severe pre-eclampsia (6.06, 5.35 to 6.86) or with both HDP and diabetes history (1.57, 1.16 to 2.14) or HDP and low education level (1.49, 1.34 to 1.66).

CONCLUSION

Maternal HDP, particularly eclampsia and severe pre-eclampsia, is associated with increased risks of overall mortality and various cause specific mortalities in offspring from birth to young adulthood.

Down-Regulation of PLAC1 in the Placenta of Gestational Diabetes Mellitus Patients and its Clinical Significance

Background: Placenta-specific 1 (PLAC1) is specifically expressed in the placenta and plays a fundamental role in placenta function. Aberrant expression of PLAC1 has been reported in pregnancy-related disorders; however, its expression in gestational diabetes mellitus (GDM) has not been clearly elucidated. This study aimed to investigate the expression of PLAC1 in the placenta of GDM patients, and its relationship with clinical characteristics. Methods: This was a case-control study. Placental tissues were collected from 37 GDM patients (GDM group) and 38 pregnant women with normal glucose tolerance (control group), matched with respect to maternal age and gestational weeks. We examined the expression of PLAC1 in the placenta of both groups and determined its association with clinical indicators. The localization of PLAC1 was confirmed by immunohistochemistry analyses. Results: PLAC1 expression was significantly lower in the placenta of GDM patients. For the control group, PLAC1 was positively correlated with pre-pregnancy body mass index (BMI), BMI at delivery, the fasting insulin, triglyceride levels, and homeostasis model assessment during delivery. In the case of GDM patients, there was no correlation between PLAC1 and these indices. Additionally, PLAC1 protein was mainly expressed in the cytoplasm of syncytiotrophoblasts and chorionic stromal cells. Conclusions: The expression of PLAC1 was reduced in the GDM placenta, which provides insight into the pathophysiological changes occurring in the placenta of these patients.

Killing two birds with one stone: Pregnancy is a sensitive window for endocrine effects on both the mother and the fetus

Pregnancy is a complex process requiring tremendous physiological changes in the mother in order to fulfill the needs of the growing fetus, and to give birth, expel the placenta and nurse the newborn. These physiological modifications are accompanied with psychological changes, as well as with variations in habits and behaviors. As a result, this period of life is considered as a sensitive window as impaired functional and physiological changes in the mother can have short- and long-term impacts on her health. In addition, dysregulation of the placenta and of mechanisms governing placentation have been linked to chronic diseases later-on in life for the fetus, in a concept known as the Developmental Origin of Health and Diseases (DOHaD). This concept stipulates that any change in the environment during the pre-conception and perinatal (in utero life and neonatal) period to puberty, can be "imprinted" in the organism, thereby impacting the health and risk of chronic diseases later in life. Pregnancy is a succession of events that is regulated, in large part, by hormones and growth factors. Therefore, small changes in hormonal balance can have important effects on both the mother and the developing fetus. An increasing number of studies demonstrate that exposure to endocrine disrupting compounds (EDCs) affect both the mother and the fetus giving rise to growing concerns surrounding these exposures. This review will give an overview of changes that happen during pregnancy with respect to the mother, the placenta, and the fetus, and of the current literature regarding the effects of EDCs during this specific sensitive window of exposure.

A Review of Nanotechnology for Treating Dysfunctional Placenta

The placenta plays a significant role during pregnancy. Placental dysfunction contributes to major obstetric complications, such as fetal growth restriction and preeclampsia. Currently, there is no effective treatment for placental dysfunction in the perinatal period, and prophylaxis is often delivered too late, at which point the disease manifestation cannot be prevented. However, with recent integration of nanoscience and medicine to perform elaborate experiments on the human placenta, it is expected that novel and efficient nanotherapies will be developed to resolve the challenge of managing placental dysfunction. The advent of nanomedicine has enabled the safe and targeted delivery of drugs using nanoparticles. These smart nanoparticles can load the necessary therapeutic substances that specifically target the placenta, such as drugs, targeting molecules, and ligands. Packaging multifunctional molecules into specific delivery systems with high targeting ability, diagnosis, and treatment has emerged as a novel theragnostic (both therapeutic and diagnostic) approach. In this review, the authors discuss recent advances in nanotechnology for placental dysfunction treatment. In particular, the authors highlight potential candidate nanoparticle-loaded molecules that target the placenta to improve utero-placental blood flow, and reduce reactive oxygen species and oxidative stress. The authors intend to provide basic insight and understanding of placental dysfunction, potential delivery targets, and recent research on placenta-targeted nanoparticle delivery systems for the potential treatment of placental dysfunction. The authors hope that this review will sensitize the reader for continued exploration of novel nanomedicines.

Placental pathology predicts infantile neurodevelopment

The aim of present study was to investigate the association of placental pathological findings with infantile neurodevelopment during the early 40 months of life. 258 singleton infants were enrolled in the Hamamatsu Birth Cohort for Mothers and Children (HBC Study) whose placentas were saved in our pathological division. To assess the infantile neurodevelopment, we used Mullen Scales of Early Learning (gross motor, visual reception, fine motor, receptive language, expressive language) at 10, 14, 18, 24, 32, and 40 months. For obtaining placental blocks, we carried out random sampling and assessed eleven pathological findings using mixed modeling identified ‘Accelerated villous maturation’, ‘Maternal vascular malperfusion’, and ‘Delayed villous maturation’ as significant predictors of the relatively lower MSEL composite scores in the neurodevelopmental milestones by Mullen Scales of Early Learning. On the other hand, ‘Avascular villi’, ‘Thrombosis or Intramural fibrin deposition’, ‘Fetal vascular malperfusion’, and ‘Fetal inflammatory response’ were significant predictors of the relatively higher MSEL composite scores in the neurodevelopmental milestones by Mullen Scales of Early Learning. In conclusion, the present study is the first to report that some placental pathological findings are bidirectionally associated with the progression of infantile neurodevelopment during 10–40 months of age.

NLRP3 inflammasome activation in gestational diabetes mellitus placentas is associated with hydrogen sulfide synthetase deficiency

The placenta may play a key role in the activation of inflammation and initiation of insulin resistance (IR) during gestational diabetes mellitus (GDM) pathogenesis. Interleukin (IL)-1β and IL-18, regulated by NLR family pyrin domain containing-3 (NLRP3) inflammasome, are important inflammatory cytokines in the initiation of maternal IR during GDM. However, the mechanism responsible for the regulatory of NLRP3 inflammasome in placenta remains unknown. Hydrogen sulfide (H₂S) exerts anti-inflammatory function partially via suppressing the activation of the NLPR3 inflammasome. The present study aimed to investigate the role of NLRP3 inflammasome, H₂S synthetase cystathionine-γ-lyase (CSE) and cystathionine-β-synthetase (CBS) in placenta in the pathogenesis of GDM. Clinical placenta samples were collected from pregnant women with GDM (n=16) and healthy pregnant women at term (n=16). Western blot analysis was performed to detect the protein expression levels of NLRP3, cleaved caspase-1, CBS and CSE in the placenta samples. Pearson's correlation analysis was performed to assess the correlation between NLRP3 inflammasome and H₂S synthetase. Human placental cells were cultured and treated with different concentrations of NaHS (0, 10, 25 and 50 nmol/l) or L-cysteine (0, 0.25, 0.50 and 1.00 mmol/l). In addition, western blot analysis was performed to detect the protein expression levels of NLRP3 and cleaved caspase-1, while ELISA was performed to measure the production of IL-1β and IL-18 in the culture media. The results demonstrated that the expression levels of NLRP3 and cleaved caspase-1 increased, while the expression levels of CBS and CSE decreased in the placenta samples. In addition, the expression levels of NLRP3 and cleaved caspase-1 were inversely correlated with the expression levels of CBS and CSE. Notably, NaHS and L-cysteine significantly suppressed the expression levels of NLRP3 and cleaved caspase-1, and the production of IL-1 and IL-18 in human placental cells. Taken together, the results of the present study suggest that H₂S synthetase deficiency in placenta may contribute to excessive activation of NLRP3 inflammasome in GDM.

Prenatal administration of IL-1Ra attenuate the neurodevelopmental impacts following non-pathogenic inflammation during pregnancy

Prenatal inflammation negatively affects placental function, subsequently altering fetal development. Pathogen-associated molecular patterns (PAMPs) are used to mimics infections in preclinical models but rarely detected during pregnancy. Our group previously developed an animal model of prenatal exposure to uric acid (endogenous mediator), leading to growth restriction alongside IL-1-driven placental inflammation (Brien et al. in J Immunol 198(1):443–451, 2017). Unlike PAMPs, the postnatal impact of prenatal non-pathogenic inflammation is still poorly understood. Therefore, we investigated the effects of prenatal uric acid exposure on postnatal neurodevelopment and the therapeutic potential of the IL-1 receptor antagonist; IL-1Ra. Uric acid induced growth restriction and placental inflammation, which IL-1Ra protected against. Postnatal evaluation of both structural and functional aspects of the brain revealed developmental changes. Both astrogliosis and microgliosis were observed in the hippocampus and white matter at postnatal day (PND)7 with IL-1Ra being protective. Decreased myelin density was observed at PND21, and reduced amount of neuronal precursor cells was observed in the Dentate Gyrus at PND35. Functionally, motor impairments were observed as evaluated with the increased time to fully turn upward (180 degrees) on the inclined plane and the pups were weaker on the grip strength test. Prenatal exposure to sterile inflammation, mimicking most clinical situation, induced growth restriction with negative impact on neurodevelopment. Targeted anti-inflammatory intervention prenatally could offer a strategy to protect brain development during pregnancy.

Maternal antioxidant treatment protects adult offspring against memory loss and hippocampal atrophy in a rodent model of developmental hypoxia

Chronic fetal hypoxia is one of the most common outcomes in complicated pregnancy in humans. Despite this, its effects on the long-term health of the brain in offspring are largely unknown. Here, we investigated in rats whether hypoxic pregnancy affects brain structure and function in the adult offspring and explored underlying mechanisms with maternal antioxidant intervention. Pregnant rats were randomly chosen for normoxic or hypoxic (13% oxygen) pregnancy with or without maternal supplementation with vitamin C in their drinking water. In one cohort, the placenta and fetal tissues were collected at the end of gestation. In another, dams were allowed to deliver naturally, and offspring were reared under normoxic conditions until 4 months of age (young adult). Between 3.5 and 4 months, the behavior, cognition and brains of the adult offspring were studied. We demonstrated that prenatal hypoxia reduced neuronal number, as well as vascular and synaptic density, in the hippocampus, significantly impairing memory function in the adult offspring. These adverse effects of prenatal hypoxia were independent of the hypoxic pregnancy inducing fetal growth restriction or elevations in maternal or fetal plasma glucocorticoid levels. Maternal vitamin C supplementation during hypoxic pregnancy protected against oxidative stress in the placenta and prevented the adverse effects of prenatal hypoxia on hippocampal atrophy and memory loss in the adult offspring. Therefore, these data provide a link between prenatal hypoxia, placental oxidative stress, and offspring brain health in later life, providing insight into mechanism and identifying a therapeutic strategy.

Mitochondria antioxidant protection against cardiovascular dysfunction programmed by early-onset gestational hypoxia

Mitochondria-derived oxidative stress during fetal development increases cardiovascular risk in adult offspring of pregnancies complicated by chronic fetal hypoxia. We investigated the efficacy of the mitochondria-targeted antioxidant MitoQ in preventing cardiovascular dysfunction in adult rat offspring exposed to gestational hypoxia, integrating functional experiments in vivo, with those at the isolated organ and molecular levels. Rats were randomized to normoxic or hypoxic (13%-14% O₂ ) pregnancy ± MitoQ (500 μM day^-1 ) in the maternal drinking water. At 4 months of age, one cohort of male offspring was chronically instrumented with vascular catheters and flow probes to test in vivo cardiovascular function. In a second cohort, the heart was isolated and mounted onto a Langendorff preparation. To establish mechanisms linking gestational hypoxia with cardiovascular dysfunction and protection by MitoQ, we quantified the expression of antioxidant system, β-adrenergic signaling, and calcium handling genes in the fetus and adult, in frozen tissues from a third cohort. Maternal MitoQ in hypoxic pregnancy protected offspring against increased α₁ -adrenergic reactivity of the cardiovascular system, enhanced reactive hyperemia in peripheral vascular beds, and sympathetic dominance, hypercontractility and diastolic dysfunction in the heart. Inhibition of Nfe2l2-mediated oxidative stress in the fetal heart and preservation of calcium regulatory responses in the hearts of fetal and adult offspring link molecular mechanisms to the protective actions of MitoQ treatment of hypoxic pregnancy. Therefore, these data show the efficacy of MitoQ in buffering mitochondrial stress through NADPH-induced oxidative damage and the prevention of programmed cardiovascular disease in adult offspring of hypoxic pregnancy.

Developmental programming of cardiovascular function: a translational perspective

The developmental origins of health and disease (DOHaD) is a concept linking pre- and early postnatal exposures to environmental influences with long-term health outcomes and susceptibility to disease. It has provided a new perspective on the etiology and evolution of chronic disease risk, and as such is a classic example of a paradigm shift. What first emerged as the 'fetal origins of disease', the evolution of the DOHaD conceptual framework is a storied one in which preclinical studies played an important role. With its potential clinical applications of DOHaD, there is increasing desire to leverage this growing body of preclinical work to improve health outcomes in populations all over the world. In this review, we provide a perspective on the values and limitations of preclinical research, and the challenges that impede its translation. The review focuses largely on the developmental programming of cardiovascular function and begins with a brief discussion on the emergence of the 'Barker hypothesis', and its subsequent evolution into the more-encompassing DOHaD framework. We then discuss some fundamental pathophysiological processes by which developmental programming may occur, and attempt to define these as 'instigator' and 'effector' mechanisms, according to their role in early adversity. We conclude with a brief discussion of some notable challenges that hinder the translation of this preclinical work.

Nanoparticles in pregnancy: the next frontier in reproductive therapeutics

BACKGROUND

Nanotechnology involves the engineering of structures on a molecular level. Nanomedicine and nano-delivery systems have been designed to deliver therapeutic agents to a target site or organ in a controlled manner, maximizing efficacy while minimizing off-target effects of the therapeutic agent administered. In both reproductive medicine and obstetrics, developing innovative therapeutics is often tempered by fears of damage to the gamete, embryo or developing foetus or of negatively impacting a woman's reproductive potential. Thus, nanomedicine delivery systems may provide alternative targeted intervention strategies, treating the source of the disease and minimizing long-term consequences for the mother and/or her foetus.

OBJECTIVE AND RATIONALE

This review summarizes the current state of nanomedicine technology in reproductive medicine and obstetrics, including safety, potential applications, future directions and the hurdles for translation.

SEARCH METHODS

A comprehensive electronic literature search of PubMed and Web of Science databases was performed to identify studies published in English up until February 2020. Relevant keywords were used to obtain information regarding use of nanoparticle technology in fertility and gene therapy, early pregnancy complications (ectopic pregnancy and gestational trophoblastic disease) and obstetric complications (preeclampsia, foetal growth restriction, preterm birth and gestational diabetes) and for selective treatment of the mother or foetus. Safety of specific nanoparticles to the gamete, embryo and foetus was also investigated.

OUTCOMES

Pre-clinical research in the development of nanoparticle therapeutic delivery is being undertaken in many fields of reproductive medicine. Non-hormonal-targeted nanoparticle therapy for fibroids and endometriosis may provide fertility-sparing medical management. Delivery of interventions via nanotechnology provides opportunities for gene manipulation and delivery in mammalian gametes. Targeting cytotoxic treatments to early pregnancy tissue provides an alternative approach to manage ectopic pregnancies and gestational trophoblastic disease. In pregnancy, nanotherapeutic delivery offers options to stably deliver silencing RNA and microRNA inhibitors to the placenta to regulate gene expression, opening doors to novel genetic treatments for preeclampsia and foetal growth restriction. Restricting delivery of teratogenic drugs to the maternal compartment (such as warfarin) may reduce risks to the foetus. Alternatively, targeted delivery of drugs to the foetus (such as those to treat foetal arrythmias) may minimize side effects for the mother.

WIDER IMPLICATIONS

We expect that further development of targeted therapies using nanoparticles in a reproductive setting has promise to eventually allow safe and directed treatments for conditions impacting the health and reproductive capacity of women and for the management of pregnancy and serious pregnancy complications.

Targeting the Dysfunctional Placenta to Improve Pregnancy Outcomes Based on Lessons Learned in Cancer

In recent decades, our understanding of the disrupted mechanisms that contribute to major obstetrical diseases, including preeclampsia, fetal growth restriction, preterm birth, and gestational diabetes, has increased exponentially. Common to many of these obstetric diseases is placental maldevelopment and dysfunction; the placenta is a significant component of the maternal-fetal interface involved in coordinating, facilitating, and regulating maternal and fetal nutrient, oxygen and waste exchange, and hormone and cytokine production. Despite the advances in our understanding of placental development and function, there are currently no treatments for placental maldevelopment and dysfunction. However, given the transient nature and accessibility from the maternal circulation, the placenta offers a unique opportunity to develop targeted therapeutics for routine obstetric practices. Furthermore, given the similar developmental paradigms between the placenta and cancer, there is an opportunity to appropriate current knowledge from advances in targeted therapeutics in cancer treatments. In this review, we highlight the similarities between early placental development and cancer and introduce a number of targeted therapies currently being explored in cancer and pregnancy. We also propose a number of new effectors currently being targeted in cancer research that have the potential to be targeted in the development of treatments for pregnancy complications. Finally, we describe a method for targeting the placenta using nonviral polymers that are capable of delivering plasmids, small interfering RNA, and other effector nucleic acids, which could ultimately improve fetal and maternal outcomes from complicated pregnancies.

Placental treatment improves cardiac tolerance to ischemia/reperfusion insult in adult male and female offspring exposed to prenatal hypoxia

Offspring born from complicated pregnancies are at greater risk of cardiovascular disease in adulthood. Prenatal hypoxia is a common pregnancy complication that results in placental oxidative stress and impairs fetal development. Adult offspring exposed to hypoxia during fetal life are more susceptible to develop cardiac dysfunction, and show decreased cardiac tolerance to an ischemia/reperfusion (I/R) insult. To improve offspring cardiac outcomes, we have assessed the use of a placenta-targeted intervention during hypoxic pregnancies, by encapsulating the mitochondrial antioxidant MitoQ into nanoparticles (nMitoQ). We hypothesized that maternal nMitoQ treatment during hypoxic pregnancies improves cardiac tolerance to I/R insult in adult male and female offspring. Pregnant Sprague-Dawley rats were exposed to normoxia (21 % O²) or hypoxia (11 % O²) from gestational day 15-20, after injection with 100 μL saline or nMitoQ (125 μM) on GD15 (n=6-8/group). Male and female offspring were aged to 4 months. Both male and female offspring from hypoxic pregnancies showed reduced cardiac tolerance to I/R (assessed ex vivo using the isolated working heart technique) which was ameliorated by nMitoQ treatment. To identify potential molecular mechanisms for the changes in cardiac tolerance to I/R, cardiac levels/phosphorylation of proteins important for intracellular Ca²⁺ cycling were assessed with Western blotting. In prenatally hypoxic male offspring, improved cardiac recovery from I/R by nMitoQ was accompanied by increased cardiac phospholamban and phosphatase 2Ce levels, and a trend to decreased Ca²⁺/calmodulin-dependent protein kinase IIδ phosphorylation. In contrast, in female offspring, nMitoQ treatment in hypoxic pregnancies increased phospholamban and protein kinase Cε phosphorylation. Maternal nMitoQ treatment improves cardiac tolerance to I/R insult in adult offspring and thus has the potential to improve the later-life trajectory of cardiovascular health of adult offspring born from pregnancies complicated by prenatal hypoxia.

Cinnamaldehyde mitigates placental vascular dysfunction of gestational diabetes and protects from the associated fetal hypoxia by modulating placental angiogenesis, metabolic activity and oxidative stress

Gestational diabetes mellitus (GDM) is a major pregnancy-related disorder with an increasing prevalence worldwide. GDM is associated with altered placental vascular functions and has severe consequences for fetal growth. There is no commonly accepted medication for GDM due to safety considerations. Actions of the currently limited therapeutic options focus exclusively on lowering the blood glucose level without paying attention to the altered placental vascular reactivity and remodelling. We used the fat-sucrose diet/streptozotocin (FSD/STZ) rat model of GDM to explore the efficacy of cinnamaldehyde (Ci; 20 mg/kg/day), a promising antidiabetic agent for GDM, and glyburide/metformin-HCl (Gly/Met; 0.6 + 100 mg/kg/day), as a reference drug for treatment of GDM, on the placenta structure and function at term pregnancy after their oral intake one week before mating onward. Through genome-wide transcriptome, biochemical, metabolome, metal analysis and histopathology we obtained an integrated understanding of their effects. GDM resulted in maternal and fetal hyperglycemia, fetal hyperinsulinemia and placental dysfunction with subsequent fetal anemia, hepatic iron deficiency and high serum erythropoietin level, reflecting fetal hypoxia. Differentially-regulated genes were overrepresented for pathways of angiogenesis, metabolic transporters and oxidative stress. Despite Ci and Gly/Met effectively alleviated the maternal and fetal glycemia, only Ci offered substantial protection from GDM-associated placental vasculopathy and prevented the fetal hypoxia. This was explained by Ci's impact on the molecular regulation of placental angiogenesis, metabolic activity and redox signaling. In conclusion, Ci provides a dual impact for the treatment of GDM at both maternal and fetal levels through its antidiabetic effect and the direct placental vasoprotective action. Lack of Gly/Met effectiveness to restore it's impaired functionality demonstrates the vital role of the placenta in developing efficient medications for GDM.

Nanoparticle-encapsulated antioxidant improves placental mitochondrial function in a sexually dimorphic manner in a rat model of prenatal hypoxia

Pregnancy complications associated with prenatal hypoxia lead to increased placental oxidative stress. Previous studies suggest that prenatal hypoxia can reduce mitochondrial respiratory capacity and mitochondrial fusion, which could lead to placental dysfunction and impaired fetal development. We developed a placenta-targeted treatment strategy using a mitochondrial antioxidant, MitoQ, encapsulated into nanoparticles (nMitoQ) to reduce placental oxidative stress and (indirectly) improve fetal outcomes. We hypothesized that, in a rat model of prenatal hypoxia, nMitoQ improves placental mitochondrial function and promotes mitochondrial fusion in both male and female placentae. Pregnant rats were treated with saline or nMitoQ on gestational day (GD) 15 and exposed to normoxia (21% O₂ ) or hypoxia (11% O₂ ) from GD15-21. On GD21, male and female placental labyrinth zones were collected for mitochondrial respirometry assessments, mitochondrial content, and markers of mitochondrial biogenesis, fusion and fission. Prenatal hypoxia reduced complex IV activity and fusion in male placentae, while nMitoQ improved complex IV activity in hypoxic male placentae. In female placentae, prenatal hypoxia decreased respiration through the S-pathway (complex II) and increased N-pathway (complex I) respiration, while nMitoQ increased fusion in hypoxic female placentae. No changes in mitochondrial content, biogenesis or fission were found. In conclusion, nMitoQ improved placental mitochondrial function in male and female placentae from fetuses exposed to prenatal hypoxia, which may contribute to improved placental function. However, the mechanisms (ie, changes in mitochondrial respiratory capacity and mitochondrial fusion) were distinct between the sexes. Treatment strategies targeted against placental oxidative stress could improve placental mitochondrial function in complicated pregnancies.

The challenge of using nanotherapy during pregnancy: Technological aspects and biomedical implications

During the period of pregnancy, several processes and physiological adaptations occur in the body and metabolism of pregnant woman. These physiological adaptations in pregnant woman end up leading to a suppression in immune system favoring obstetric complications to the mother, fetus and placental tissue. An effective pharmacological therapy for these complications is still a challenge, since some drugs during pregnancy can have deleterious and teratogenic effects. An emerging alternative to pharmacological therapy during pregnancy is drugs encapsulated in nanoparticles (NP), recent area called nano-obstetrics. NP have the advantage of drug targeting and reduction of side effects. Then, maternal, placental or fetal uptake can be expected, depending on the characteristics of NP. Inorganic NP, crossing placental barrier effectively, but have several nanotoxicological effects. While organic NP appear to have a better targeting capacity and have few toxicological effects, but the studies are still scarce. Thus, in this review, were examined questions related to use and impact of physicochemical aspects of inorganic and organic NP during pregnancy.