During mouse embryonic development, vasculogenesis initially occurs in the yolk sac, preceding neurulation. Our previous studies have demonstrated that maternal diabetes induces embryonic vasculopathy at early embryonic developmental stage by suppressing the expression of vascular growth factors including BMP4 (bone morphogenetic protein 4). This study aimed to determine whether restoring diabetes-inhibited BMP4 expression in Flk-1(+) progenitors effectively prevented maternal diabetes-induced embryonic vasculopathy and NTDs. Transgenic (Tg) BMP4 expression in the vascular endothelial growth factor receptor 2 (Flk-1)-positive (Flk-1(+)) progenitors was achieved by crossing a Floxed BMP4 Tg mouse line with the Flk-1-Cre mouse line. Non-BMP4 Tg and BMP4 Tg embryos were harvested at E8.5 to assess the expression of BMP4, markers of endoplasmic reticulum stress, and expression of the Id genes, direct targets of BMP4; and the presence of cleaved caspase 3 and 8, apoptosis, and Smad signaling. BMP4 Tg overexpression neutralized its down-regulation by maternal diabetes in E8.5 embryos. Maternal diabetes-induced Flk-1(+) progenitor apoptosis, impairment of blood island formation, and reduction of Flk-1(+) progenitor number and blood vessel density, which were reversed by BMP4 Tg expression. BMP4 Tg expression in Flk-1(+) progenitors blocked maternal diabetes-induced vasculopathy in early stage embryos (E7.5-E8.5) and consequently led to amelioration of maternal diabetes-induced neural tube defects (NTDs) at E10.5. BMP4 Tg expression inhibited maternal diabetes-induced endoplasmic reticulum stress and caspase cascade activation in the developing neuroepithelium, and reduced neuroepithelial cell apoptosis. BMP4 Tg expression re-activated Smad1/5/8 phosphorylation and reversed maternal diabetes-suppressed Smad4 expression. BMP4 Tg expression restored Id1 and Smad6 expression inhibited by maternal diabetes. In vitro, recombinant BMP4 protein blocked high glucose-induced Flk-1(+) progenitor apoptosis and NTDs. These data demonstrate that BMP4 down-regulation in Flk-1(+) progenitors are responsible for diabetes-induced yolk sac vasculopathy, and that restoring BMP4 expression prevents vasculopathy and rescues neuroepithelial cells from cellular organelle stress, leading to NTD reduction.
The US biomedical research enterprise is renowned for its historical and ongoing scientific breakthroughs and advancements. Yet its capacity to solve complex health issues, bridge health equity gaps, and strengthen public trust is constrained by the lack of an overarching national vision, fragmented coordination for research funding, and critical workforce recruitment and retention challenges. To improve national health outcomes and retain global competitiveness, the sector must embrace new approaches. This article, part of the National Academy of Medicine's Vital Directions for Health and Health Care: Priorities for 2025 initiative, identifies four key opportunities to revitalize the biomedical research enterprise: establishing a national advisory body, bolstering the workforce, prioritizing research to reduce health disparities, and developing approaches to streamlining and coordinating federal research funding. These priorities will help the biomedical research enterprise meet twenty-first-century challenges, promote healthy longevity, and preserve US leadership in the global arena.
This study aimed to assess the strengths, limitations, opportunities, and threats presented by diabetes-in-pregnancy. We review the improvements in maternal and fetal mortality since the advent of insulin therapy, evaluate current health challenges, and identify opportunities for preventing increased mortality due to diabetes-in-pregnancy. Prior to 1922, women with type 1 diabetes mellitus (T1DM) of childbearing age were discouraged from becoming pregnant as the maternal and fetal/neonatal mortality rates were extremely high. Starvation-level dietary restriction was the only “treatment,” with limited success in managing the disease. The discovery of insulin coupled with careful clinical management presented the possibility of successful pregnancies for women with T1dm. Over the course of the next half-century, maternal survival increased from 54 to 97%. However, the gains made in reducing adverse outcomes of diabetes in pregnancy are eroding due to modern challenges. The global obesity epidemic has led to an increase in type 2 and gestational diabetes mellitus (DM). T1DM also is on the rise. Together, the rise in the prevalence of pregestational diabetes has increased the risks for adverse outcomes. Here we review the ongoing challenges as well as opportunities for research to improve outcomes. We suggest that overweight, obesity, and diabetes management must be coupled with preconception counseling and education and must include, in addition to, Ob/Gyns, primary care, nutrition, weight management, and other experts to ensure that those at risk of pregnancy complications due to diabetes have the best possible outcomes. Key Points
Blood samples and testing are routine in healthcare. Presently, there is a growing interest in using tear samples in place of blood. Tear samples can be obtained non-invasively and collection does not require the skills of a trained phlebotomist. Red blood cells and other cells are not present in tears, which avoids centrifugation. Importantly, basal tear samples contain most of the biomarkers present in blood. The difficulty is the small volume of basal tears, which is about 7 μL in each eye. Any contact with the eye results in additional reflex tears with a different chemical composition. The small tear samples are collected with capillary tubes and then sent out for amplified assays, such as enzyme-linked immunosorbent assay (ELISA) or polymerase chain reaction (PCR). The results are not available for several days or a week and, therefore, are less useful in an ophthalmology office. We propose the use of a contact lens that contains bound antibodies for fluorescence immunoassays. The lenses could be removed from the patient for point-of-care measurements at the bedside. To prove that this concept is possible, we performed a three-layer protein capture assay that mimics an immunoassay. For convenience, we used lysozyme (Lys), which spontaneously coats silicon hydrogel (SiHG) contact lenses (CL). Anti-lysozyme IgG was the second layer captured, with anti-lysozyme considered to be the target biomarker. The third layer was rhodamine or Alexa Fluor-labeled Ab against the IgG Fc region, considered to be the detection antibody. The multiple protein layers were stable and did not wash off the SiHG lenses. These results strongly suggest the contact lens can be used for capture immunoassays for a wide variety of biomarkers.
The neurotropism of SARS-CoV-2 and the phenotypes of infected neurons are still in debate. Long COVID manifests with “brain diseases” and the cause of these brain dysfunction is mysterious. Here, we analyze 34 age- and underlying disease-matched COVID-19 or non-COVID-19 human brains. SARS-CoV-2 RNA, nucleocapsid, and spike proteins are present in neurons of the cognitive centers of all COVID-19 patients, with its non-structural protein NSF2 detected in adult cases but not in the infant case, indicating viral replications in mature neurons. In adult COVID-19 patients without underlying neurodegeneration, SARS-CoV-2 infection triggers Aβ and p-tau deposition, degenerating neurons, microglia activation, and increased cytokine, in some cases with Aβ plaques and p-tau pretangles. The number of SARS-CoV-2 + cells is higher in patients with neurodegenerative diseases than in those without such conditions. SARS-CoV-2 further activates microglia and induces Aβ and p-tau deposits in non-Alzheimer’s neurodegenerative disease patients. SARS-CoV-2 infects mature neurons derived from inducible pluripotent stem cells from healthy and Alzheimer’s disease (AD) individuals through its receptor ACE2 and facilitator neuropilin-1. SARS-CoV-2 triggers AD-like gene programs in healthy neurons and exacerbates AD neuropathology. An AD infectious etiology gene signature is identified through SARS-CoV-2 infection and silencing the top three downregulated genes in human primary neurons recapitulates the neurodegenerative phenotypes of SARS-CoV-2. Thus, our data suggest that SARS-CoV-2 invades the brain and activates an AD-like program.
This Viewpoint discusses the need for the US to foster public-private partnerships, advance convergence science, and prioritize workforce development in order to maintain its position as a global leader in biomedical research, particularly in the face of rising competition from countries around the world.
Dehydration is a serious medical problem for elderly patients and young children. The most widely used diagnostics are measurements of sodium ion (Na+) and potassium ion (K+) in blood serum. Dehydration is difficult to diagnose even by trained health care professionals because the body compensates to maintain the appearance of skin. These measurements required a blood draw because specific tests are generally not available for only Na+ and K+. The blood samples are analyzed by an electrolyte panel (EP) or a basic metabolic panel (BMP). Most hospitals limit EP and BMP to one per day to control costs. More frequent measurements of Na+ and K+ are needed, especially during rehydration. We designed a dehydration contact lens that can provide the Na+ and K+ concentrations as needed or for continuous monitoring. The measurements are obtained from the fluorescent lifetime or wavelength-ratiometric intensities of the Na+- and K+-sensitive fluorophores. The dehydration contact lens does not contain electronic components and are inexpensive to prepare.
Pregestational diabetes complicates 1% to 2% of all pregnancies. Achievement of euglycemia prevents adverse maternal, fetal, and neonatal outcomes. Insulin is the first line and the backbone of diabetes treatment in and out of pregnancy, but the delicate balance between stringent control and hypoglycemia, along with the complexity and interruption of multiple injections per day, continues to make glycemic control challenging. The ideal basal insulin has a flat pharmacodynamic profile with minimal variability and is relatively easy for patients and clinicians to use. Insulin analogs, such as insulins glargine and detemir, are the most common basal insulins used in pregnancy at this time, but insulin degludec, which has advantages like prolonged duration of action in the nonpregnant population, was recently shown to be equally as effective as detemir in pregnancy. The ease of a once-daily injection without an increased risk of hypoglycemia is attractive to patients and clinicians who wish to simplify insulin regimens. Furthermore, there are current clinical trials evaluating once-weekly basal insulin regimens in the general population. This would decrease basal injections from a minimum of 365 per year to 52 per year, potentially increasing adherence and improving glycemic control. This review will discuss the evidence for insulin degludec in pregnancy as well as discuss the potential benefits and drawbacks of once-weekly ultralong-acting basal insulins in pregnancy.
OBJECTIVE:Pregnant women are at increased risk of coronavirus disease 2019 (COVID-19). This could be explained through the prism of physiologic and immunologic changes in pregnancy. In addition, certain immunological reactions originate in the placenta in response to viral infections.This study aimed to investigate whether severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) can infect the human placenta and discuss its implications in the pathogenesis of adverse pregnancy outcomes. STUDY DESIGN:We conducted a retrospective cohort study in which we collected placental specimens from pregnant women who had a laboratory-confirmed SARS-CoV-2 infection. We performed RNA in situ hybridization assay on formalin-fixed paraffin-embedded tissues to establish the in vivo evidence for placental infectivity by this corona virus. In addition, we infected trophoblast isolated from uninfected term human placenta with SARS-CoV-2 variants to further provide in vitro evidence for such an infectivity. RESULTS:There was a total of 21 cases enrolled, which included 5 cases of spontaneous preterm birth (SPTB) and 2 intrauterine fetal demises (IUFDs). Positive staining of positive-sense strand of SARS-CoV-2 virions was detected in 15 placentas including 4 SPTB and both IUFDs. In vitro infection assay demonstrated that SARS-CoV-2 virions were highly capable of infecting both cytotrophoblast and syncytiotrophoblast. CONCLUSION:This study implies that placental SARS-CoV-2 infection may be associated with an increased risk of adverse obstetrical outcomes. KEY POINTS:· SARS-CoV-2 can effectively infect human placenta.. · Such infectivity is confirmed by in vitro experiments.. · Placental SARS-CoV-2 corelates with adverse obstetrical outcomes..
BACKGROUND: Hyperglycemia from pregestational diabetes mellitus induces neural tube defects in the developing fetus. Folate supplementation is the only effective way to prevent neural tube defects; however, some cases of neural tube defects are resistant to folate. Excess folate has been linked to higher maternal cancer risk and infant allergy. Therefore, additional interventions are needed. Understanding the mechanisms underlying maternal diabetes mellitus-induced neural tube defects can identify potential targets for preventing such defects. Despite not yet being in clinical use, growing evidence suggests that microRNAs are important intermediates in embryonic development and can serve as both biomarkers and drug targets for disease intervention. Our previous studies showed that maternal diabetes mellitus in vivo activates the inositolrequiring transmembrane kinase/endoribonuclease 1a (IRE1a) in the developing embryo and that a high glucose condition in vitro reduces microRNA-322 (miR-322) levels. IRE1a is an RNA endonuclease; however, it is unknown whether IRE1a targets and degrades miR-322 specifically or whether miR-322 degradation leads to neural tube defects via apoptosis. We hypothesize that IRE1a can inhibit miR-322 in maternal diabetes mellitus-induced neural tube defects and that restoring miR322 expression in developing neuroepithelium ameliorates neural tube defects. OBJECTIVE: This study aimed to identify potential targets for preventing maternal diabetes mellitus-induced neural tube defects and to investigate the roles and relationship of a microRNA and an RNA endonuclease in mouse embryos exposed to maternal diabetes mellitus. STUDY DESIGN: To determine whether miR-322 reduction is necessary for neural tube defect formation in pregnancies complicated by diabetes mellitus, male mice carrying a transgene expressing miR-322 were mated with nondiabetic or diabetic wide-type female mice to generate embryos with or without miR-322 overexpression. At embryonic day 8.5 when the neural tube is not yet closed, embryos were harvested for the assessment of 3 miR-322 transcripts (primary, precursor, and mature miR-322), tumor necrosis factor receptor-associated factor 3 (TRAF3), and neuroepithelium cell survival. Neural tube defect incidences were determined in embryonic day 10.5 embryos when the neural tube should be closed if there is no neural tube defect formation. To identify which miR322 transcript is affected by maternal diabetes mellitus and high glucose conditions, 3 miR-322 transcripts were assessed in embryos from dams with or without diabetes mellitus and in C17.2 mouse neural stem cells treated with different concentrations of glucose and at different time points. To determine whether the endonuclease IRE1a targets miR-322, small interfering RNA knockdown of IRE1a or overexpression of inositolrequiring transmembrane kinase/endoribonuclease 1a by DNA plasmid transfection was used to determine the effect of IRE1a deficiency or overexpression on miR-322 expression. RNA immunoprecipitation was performed to reveal the direct targets of inositol-requiring transmembrane kinase/endoribonuclease 1a. RESULTS: Maternal diabetes mellitus suppressed miR-322 expression in the developing neuroepithelium. Restoring miR-322 expression in the neuroepithelium blocked maternal diabetes mellitus-induced caspase-3 and caspase-8 cleavage and cell apoptosis, leading to a neural tube defect reduction. Reversal of maternal diabetes mellitus-inhibited miR-322 via transgenic overexpression prevented TRAF3 up-regulation in embryos exposed to maternal diabetes mellitus. Activated IRE1a acted as an endonuclease and degraded precursor miR-322, resulting in mature miR322 reduction. CONCLUSION: This study supports the crucial role of the IRE1a- microRNA-TRAF3 circuit in the induction of neuroepithelial cell apoptosis and neural tube defect formation in pregnancies complicated by diabetes mellitus and identifies IRE1a and miR-322 as potential targets for preventing maternal diabetes mellitus-induced neural tube defects.
The career path of everyone is quite unique based on the goals and the choices we make, and success can take time to unfold. My career choices have been greatly influenced by remarkable mentors and opportunities. Reciprocally I have had the pleasure, as a faculty member, department chair, and medical school dean to mentor promising young physicians and scientists to launch successful careers. We need to continue to attract physicians and scientists to academic medicine to ensure that our field continues to innovate and improve the lives of our patients. To influence positive change, we must stay relentlessly focused and have faith that success will come.
Human parturition involves many events among mother, fetus, and placenta, and the initiation of these events is the consequence of activation of a series of endocrine and immune responses. Multiple underlying pathways account for the cascade of events that culminate in spontaneous preterm labor. In this study, we aimed to characterize these signaling pathways of placental origin at molecular levels.We used single-cell RNA-sequencing (sc-RNA-seq) analysis to probe transcriptional heterogeneity in human placenta delivered at preterm or term and then used RNA in situ hybridization (RNA-ISH) assay on formalin-fixed paraffin-embedded (FFPE) placental tissues to validate these results.By using sc-RNA-seq on villous cytotrophoblast (CTB) isolated from a preterm placenta, we found that signaling pathways implicated in the initiation of term or preterm labor including ferroptosis, kisspeptin (KISS1), and senescence were constitutively activated in distinct cellular clusters of these trophoblastic stem cells. RNA-ISH-based spatial gene expression profiling in FFPE tissues revealed that pregnancy-specific beta-1-glycoprotein 4 (PSG4), a potent molecular driver for cellular aging, was significantly increased in preterm placentas (N = 30) compared to their full-term counterparts (N = 9). Furthermore, PSG4 mRNA signals were predominantly detected in the villous syncytiotrophoblast and the discontinuous monolayer of CTB as well as the intervillous space where maternal blood circulates.Our study provides strong support for PSG4 overexpression serving as a biomarker for pregnant women at risk for preterm delivery, which can allow for the development of timely and clinical preventive strategies. · A sc-RNA-seq analysis on a preterm placenta identified multiple signaling pathways constitutively activated in distinct clusters of CTB.. · RNA-ISH assay uncovered that the mRNA levels of PSG4, a molecular driver for cellular senescence significantly increased in preterm placentas compared to the term counterparts.. · PSG4 mRNA signals were largely observed in the villous trophoblast as well as the intervillous space..
Pregestational diabetes, either type 1 or type 2 diabetes, induces structural birth defects including neural tube defects and congenital heart defects in human fetuses. Rodent models of type 1 and type 2 diabetic embryopathy have been established and faithfully mimic human conditions. Hyperglycemia of maternal diabetes triggers oxidative stress in the developing neuroepithelium and the embryonic heart leading to the activation of proapoptotic kinases and excessive cell death. Oxidative stress also activates the unfolded protein response and endoplasmic reticulum stress. Hyperglycemia alters epigenetic landscapes by suppressing histone deacetylation, perturbing microRNA (miRNA) expression, and increasing DNA methylation. At cellular levels, besides the induction of cell apoptosis, hyperglycemia suppresses cell proliferation and induces premature senescence. Stress signaling elicited by maternal diabetes disrupts cellular organelle homeostasis leading to mitochondrial dysfunction, mitochondrial dynamic alteration, and autophagy impairment. Blocking oxidative stress, kinase activation, and cellular senescence ameliorates diabetic embryopathy. Deleting the mir200c gene or restoring mir322 expression abolishes maternal diabetes hyperglycemia-induced senescence and cellular stress, respectively. Both the autophagy activator trehalose and the senomorphic rapamycin can alleviate diabetic embryopathy. Thus, targeting cellular stress, miRNAs, senescence, or restoring autophagy or mitochondrial fusion is a promising approach to prevent poorly controlled maternal diabetes-induced structural birth defects. In this review, we summarize the causal events in diabetic embryopathy and propose preventions for this pathological condition. · Maternal diabetes induces structural birth defects.. · Kinase signaling and cellular organelle stress are critically involved in neural tube defects.. · Maternal diabetes increases DNA methylation and suppresses developmental gene expression.. · Cellular apoptosis and senescence are induced by maternal diabetes in the neuroepithelium.. · microRNAs disrupt mitochondrial fusion leading to congenital heart diseases in diabetic pregnancy..
In this paper, a method is described to perform ion concentration measurements on both sides of an inserted contact lens, without physical contact with the eye or the contact lens. The outer surface of an eye is covered with a tear film that has multiple layers. The central aqueous layer contains electrolytes and proteins. When a contact lens is inserted, it becomes localized in the central layer, which creates two layers known as the pre-lens tear film (PLTF) and the post-lens tear film (PoLTF). The PoLTF is in direct contact with the sensitive corneal epithelial cells which control electrolyte concentrations in tears. It is difficult to measure the overall electrolyte concentration in tears because of the small 7 μL volume of bulk tears. No methods are known, and no method has been proposed, to selectively measure the concentrations of electrolytes in the smaller volumes of the PLTF and the PoLTF. In this paper, we demonstrate the ability to localize fluorophores on each side of a contact lens without probe mixing or diffusion across the lens. We measured the concentration of sodium in the region of the PoLTF using a sodium-sensitive fluorophore positioned on the inner surface of a contact lens. The fluorescence measurements do not require physical contact and are mostly independent of eye motion and fluorophore concentration. The method is generic and can be combined with ion-sensitive fluorophores for the other electrolytes in tears. Instrumentation for non-contact measurements is likely to be inexpensive with modern opto-electronic devices. We expect these lenses to be used for measurements of other ions in the PLTF and the PoLTF, and thus become useful for both research and in the diagnosis of infections, keratitis and biomarkers for diseases.
INTRODUCTION:Studies indicate a very low rate of SARS-CoV-2 detection in the placenta or occasionally a low rate of vertical transmission in COVID-19 pregnancy. SARS-CoV-2 Delta variant has become a dominant strain over the world and possesses higher infectivity due to mutations in its spike receptor-binding motif.CASE PRESENTATION:To determine whether SARS-CoV-2 Delta variant has increased potential for placenta infection and vertical transmission, we analyzed SARS-CoV-2 infection in the placenta, umbilical cord, and fetal membrane from a case where an unvaccinated mother and her neonate were COVID-19 positive. A 35-year-old primigravida with COVID-19 underwent an emergent cesarean delivery due to placental abruption in the setting of premature rupture of membranes. The neonate tested positive for SARS-CoV-2 within the first 24 h, and then again on days of life 2, 6, 13, and 21. The placenta exhibited intervillositis, increased fibrin deposition, and syncytiotrophoblast necrosis. Sequencing of viral RNA from fixed placental tissue revealed SAR-CoV-2 B.1.167.2 (Delta) variant. Both spike protein and viral RNA were abundantly present in syncytiotrophoblasts, cytotrophoblasts, umbilical cord vascular endothelium, and fetal membranes.CONCLUSION:We report with strong probability the first SARS-CoV-2 Delta variant transplacental transmission. Placental cells exhibited extensive apoptosis, senescence, and ferroptosis after SARS-CoV-2 Delta infection.