Biology subjects

Jones, H.

Publications and source records attributed to Jones, H..

At least 37 records · Page 2Linked to original sources

bioRxiv2024

Nanoparticle-mediated delivery of placental gene therapy via uterine artery catheterization in a pregnant rhesus macaque

Nanoparticles offer promise as a mechanism to non-invasively deliver targeted placental therapeutics. Our previous studies utilizing intraplacental administration demonstrate efficient nanoparticle uptake into placental trophoblast cells and overexpression of human IGF1 (hIGF1). Nanoparticle-mediated placental overexpression of hIGF1 in small animal models of placental insufficiency and fetal growth restriction improved nutrient transport and restored fetal growth. The objective of this pilot study was to extend these studies to the pregnant nonhuman primate and develop a method for local delivery of nanoparticles to the placenta via maternal blood flow from the uterine artery. Nanoparticles containing hIGF1 plasmid driven by the placenta-specific PLAC1 promoter were delivered to a mid-gestation pregnant rhesus macaque via a catheterization approach that is clinically used for uterine artery embolization. Maternal-fetal interface, fetal and maternal tissues were collected four days post-treatment to evaluate the efficacy of hIGF1 treatment in the placenta. The uterine artery catheterization procedure and nanoparticle treatment was well tolerated by the dam and fetus through the four-day study period following catheterization. Nanoparticles were taken up by the placenta from maternal blood as plasmid-specific hIGF1 expression was detected in multiple regions of the placenta via in situ hybridization and qPCR. The uterine artery catheterization approach enabled successful delivery of nanoparticles to maternal circulation in close proximity to the placenta with no concerns to maternal or fetal health in this short-term feasibility study. In the future, this delivery approach can be used for preclinical evaluation of the long-term safety and efficacy of nanoparticle-mediated placental therapies in a rhesus macaque model. HighlightsNovel method to deliver therapeutics to maternal-fetal interface Delivery of nanoparticles to the placenta via maternal catheterization

physiology↗

bioRxiv2024

Placental Nanoparticle-mediated IGF1 Gene Therapy Corrects Fetal Growth Restriction in a Guinea Pig Model

Fetal growth restriction (FGR) caused by placental insufficiency is a major contributor to neonatal morbidity and mortality. There is currently no in utero treatment for placental insufficiency or FGR. The placenta serves as the vital communication, supply, exchange, and defense organ for the developing fetus and offers an excellent opportunity for therapeutic interventions. Here we show efficacy of repeated treatments of trophoblast-specific human insulin-like 1 growth factor (IGF1) gene therapy delivered in a non-viral, polymer nanoparticle to the placenta for the treatment of FGR. Using a guinea pig maternal nutrient restriction model (70% food intake) of FGR, nanoparticle-mediated IGF1 treatment was delivered to the placenta via ultrasound guidance across the second half of pregnancy, after establishment of FGR. This treatment resulted in correction of fetal weight in MNR + IGF1 animals compared to sham treated controls on an ad libitum diet, increased fetal blood glucose and decreased fetal blood cortisol levels compared to sham treated MNR, and showed no negative maternal side-effects. Overall, we show a therapy capable of positively impacting the entire pregnancy environment: maternal, placental, and fetal. This combined with our previous studies using this therapy at mid pregnancy in the guinea pig and in two different mouse model and three different human in vitro/ex vivo models, demonstrate the plausibility of this therapy for future human translation. Our overall goal is to improve health outcomes of neonates and decrease numerous morbidities associated with the developmental origins of disease.

physiology↗

bioRxiv2023

Rewriting regulatory DNA to dissect and reprogram gene expression

Regulatory DNA sequences within enhancers and promoters bind transcription factors to encode cell type-specific patterns of gene expression. However, the regulatory effects and programmability of such DNA sequences remain difficult to map or predict because we have lacked scalable methods to precisely edit regulatory DNA and quantify the effects in an endogenous genomic context. Here we present an approach to measure the quantitative effects of hundreds of designed DNA sequence variants on gene expression, by combining pooled CRISPR prime editing with RNA fluorescence in situ hybridization and cell sorting (Variant-FlowFISH). We apply this method to mutagenize and rewrite regulatory DNA sequences in an enhancer and the promoter of PPIF in two immune cell lines. Of 672 variant-cell type pairs, we identify 497 that affect PPIF expression. These variants appear to act through a variety of mechanisms including disruption or optimization of existing transcription factor binding sites, as well as creation of de novo sites. Disrupting a single endogenous transcription factor binding site often led to large changes in expression (up to -40% in the enhancer, and -50% in the promoter). The same variant often had different effects across cell types and states, demonstrating a highly tunable regulatory landscape. We use these data to benchmark performance of sequence-based predictive models of gene regulation, and find that certain types of variants are not accurately predicted by existing models. Finally, we computationally design 185 small sequence variants ([≤]10 bp) and optimize them for specific effects on expression in silico. 84% of these rationally designed edits showed the intended direction of effect, and some had dramatic effects on expression (-100% to +202%). Variant-FlowFISH thus provides a powerful tool to map the effects of variants and transcription factor binding sites on gene expression, test and improve computational models of gene regulation, and reprogram regulatory DNA.

genetics↗

bioRxiv2023

An encyclopedia of enhancer-gene regulatory interactions in the human genome

Identifying transcriptional enhancers and their target genes is essential for understanding gene regulation and the impact of human genetic variation on disease1-6. Here we create and evaluate a resource of >13 million enhancer-gene regulatory interactions across 352 cell types and tissues, by integrating predictive models, measurements of chromatin state and 3D contacts, and large-scale genetic perturbations generated by the ENCODE Consortium7. We first create a systematic benchmarking pipeline to compare predictive models, assembling a dataset of 10,411 element-gene pairs measured in CRISPR perturbation experiments, >30,000 fine-mapped eQTLs, and 569 fine-mapped GWAS variants linked to a likely causal gene. Using this framework, we develop a new predictive model, ENCODE-rE2G, that achieves state-of-the-art performance across multiple prediction tasks, demonstrating a strategy involving iterative perturbations and supervised machine learning to build increasingly accurate predictive models of enhancer regulation. Using the ENCODE-rE2G model, we build an encyclopedia of enhancer-gene regulatory interactions in the human genome, which reveals global properties of enhancer networks, identifies differences in the functions of genes that have more or less complex regulatory landscapes, and improves analyses to link noncoding variants to target genes and cell types for common, complex diseases. By interpreting the model, we find evidence that, beyond enhancer activity and 3D enhancer-promoter contacts, additional features guide enhancer-promoter communication including promoter class and enhancer-enhancer synergy. Altogether, these genome-wide maps of enhancer-gene regulatory interactions, benchmarking software, predictive models, and insights about enhancer function provide a valuable resource for future studies of gene regulation and human genetics.

genomics↗

bioRxiv2023

Hif-2α programmes oxygen chemosensitivity in chromaffin cells

The study of transcription factors that determine specialised neuronal functions has provided invaluable insights into the physiology of the nervous system. Peripheral chemoreceptors are neurone-like electro-physiologically excitable cells that link the oxygen content of arterial blood to the neuronal control of breathing. In the adult, this oxygen chemosensitivity is exemplified by the Type I cells of the carotid body and recent work has revealed one isoform of the transcription factor HIF, HIF-2, to have a non-redundant role in the development and function of that organ. Here we show that the activation of HIF-2, including isolated overexpression alone, is sufficient to induce oxygen chemosensitivity in the otherwise unresponsive adult adrenal medulla. This phenotypic change in the adrenal medulla was associated with retention of extra-adrenal paraganglioma-like tissues that resemble the foetal organ of Zuckerkandl and also manifest oxygen chemosensitivity. Acquisition of chemosensitivity was associated with changes in the adrenal medullary expression of classes of genes that are ordinarily characteristic of the carotid body, including G-protein regulators and atypical subunits of mitochondrial cytochrome oxidase. Overall, the findings suggest that, at least in certain tissues, HIF-2 acts as a phenotypic driver for cells that display oxygen chemosensitivity, providing a route to mechanistic understanding.

developmental biology↗

bioRxiv2023

Maternal, placental and fetal response to a non-viral, polymetric nanoparticle gene therapy in nonhuman primates

BackgroundCurrently, there are no placenta-targeted treatments to alter the in utero environment. Water-soluble polymers have a distinguished record of clinical relevance outside of pregnancy. We have demonstrated the effective delivery of polymer-based nanoparticles containing a non-viral human insulin-like 1 growth factor (IGF1) transgene to correct placental insufficiency in small animal models of fetal growth restriction (FGR). Our goal was to extend these studies to the pregnant nonhuman primate (NHP) and assess maternal, placental and fetal responses to nanoparticle-mediated IGF1 treatment. MethodsPregnant macaques underwent ultrasound-guided intraplacental injections of nanoparticles (GFP- or IGF1-expressing plasmid under the control of the trophoblast-specific PLAC1 promoter complexed with a HPMA-DMEAMA co-polymer) at approximately gestational day 100 (term = 165 days). Fetectomy was performed 24 h (GFP; n =1), 48 h (IGF1; n = 3) or 10 days (IGF1; n = 3) after nanoparticle delivery. Routine pathological assessment was performed on biopsied maternal tissues, and placental and fetal tissues. Maternal blood was analyzed for complete blood count (CBC), immunomodulatory proteins and growth factors, progesterone (P4) and estradiol (E2). Placental ERK/AKT/mTOR signaling was assessed using western blot and qPCR. FindingsFluorescent microscopy and in situ hybridization confirmed placental uptake and transgene expression in villous syncytiotrophoblast. No off-target expression was observed in maternal and fetal tissues. Histopathological assessment of the placenta recorded observations not necessarily related to the IGF1 nanoparticle treatment. In maternal blood, CBCs, P4 and E2 remained within the normal range for pregnant macaques across the treatment period. Changes to placental ERK and AKT signaling at 48 h and 10 d after IGF1 nanoparticle treatment indicated an upregulation in placental homeostatic mechanisms to prevent over activity in the normal pregnancy environment. InterpretationMaternal toxicity profile analysis and lack of adverse reaction to nanoparticle-mediated IGF1 treatment, combined with changes in placental signaling to maintain homeostasis indicates no deleterious impact of treatment. FundingNational Institutes of Health, and Wisconsin National Primate Research Center.

physiology↗

bioRxiv2023

Nutritional and genetic variations within foxtail millet (Setaria italica) landraces collected from indigenous communities across the Philippines

Unknown to many, the Philippines is host to a few remaining accessions of the underutilized and understudied cereal foxtail millet (Setaria italica (L.) P. Beauv.). We collected together accessions from different eco-geographical locations within the Philippines, along with a few accessions from Lanyu, Taiwan, to undertake a study of the nutritional value and genetic diversity within accessions of foxtail millet grown in the Philippines. All accessions were field grown in 2022, dry season (DS) at the Institute of Plant Breeding (IPB) Experiment Station, Los Banos, Laguna, Philippines. The accessions were tested for micronutrients, including Zn and Fe, nitrogen as a proxy for protein, {beta}-carotene and a number of phenolic compounds with known nutritional potential. Of the 20 accessions tested, the accessions Bayaras and GB61438 had the highest level of Zn (107.1 mg/kg) and Fe (70.52 mg/kg), respectively, higher than levels found in traditional rice varieties. For {beta}-carotene the highest concentration was found in the accession Balles ([~]10{micro}g/g). Twelve phenolic compounds were detected, with catechin, syringic acid, ferulic acid and kaempferol having the highest concentrations and greatest variation between accessions. To assess the genetic diversity of these local foxtail millet accessions, we sequenced a core set of eight accessions to a depth of at least 25-fold. Analysis of the population structure, using genome-wide, high-quality SNPs, showed modest diversity among the accession, with two unadmixed groups. The accessions are monophyletic relative to their earliest common ancestor, with the very light brown accessions emerging earlier than the light brown and reddish-brown varieties. Analysis of Zinc/Iron permease (ZIP) transporters within the foxtail millet reference sequence, var. Yugu1 identified 17 putative ZIP transporters. Variant calling identified SNPs primarily within 3 and 5 regions, and introns, indicating variation between foxtail millet accessions within regulatory gene regions rather than in structural proteins. The local foxtail millet accessions found across the Philippines, therefore, represent a potential alternative source of nutrition that would help to address the problems of the double-burden of malnutrition found in the Philippines.

plant biology↗

bioRxiv2023

Bumblebee mouthparts exhibit poor acuity for the detection of pesticides in nectar

Bees are important pollinators of agricultural crops, but their populations are at risk when pesticides are used. One of the largest risks bees face is poisoning of floral nectar and pollen by insecticides. Studies of bee detection of neonicotinoids have reported contradictory evidence about whether bees can taste these pesticides in sucrose solutions and hence avoid them. Here, we use an assay for the detection of food aversion combined with single-sensillum electrophysiology to test whether the mouthparts of the buff-tailed bumblebee (Bombus terrestris) detect the presence of pesticides in a solution that mimicked the nectar of oilseed rape (Brassica napus). Bees did not avoid consuming solutions containing concentrations of imidacloprid, thiamethoxam, clothianidin, or sulfoxaflor spanning six orders of magnitude, even when these solutions contained lethal doses. Only extremely high concentrations of the pesticides altered spiking in gustatory neurons through a slight reduction in firing rate or change in the rate of adaptation. These data provide strong evidence that bumblebees cannot detect or avoid field-relevant concentrations of pesticides using information from their mouthparts. As bees rarely contact floral nectar with other body parts, we predict that they are at high risk of unwittingly consuming pesticides in the nectar of pesticide-treated crops.

neuroscience↗

bioRxiv2023

Effect of soilless media on small-scale propagation of Pinguicula gigantea

Because of their large size, colorful flowers, and insectivorous habit, butterworts (genus Pinguicula) are desirable ornamental plants among hobbyists and botanical conservatories. Propagation via leaves is a popular propagation method for the genus, especially for tropical species. P. gigantea, a species found approximately 700m above sea level in Oaxaca, Mexico, was selected to evaluate its preference for various blends of soilless media. This study found that number of leaves produced by plantlets is significantly impacted by soil type. However, there was no significant difference in biomass, plantlet diameter or average number of plantlets produced between soil treatments. These results suggest that soils with high nitrogen content may promote increased leaf number, but do not significantly affect plant biomass.

plant biology↗

bioRxiv2022

A reductionist paradigm for high-throughput behavioural fingerprinting in Drosophila melanogaster

Understanding how the brain encodes behaviour is the ultimate goal of neuroscience and the ability to objectively and reproducibly describe and quantify behaviour is a necessary milestone on this path. Recent technological progresses in machine learning and computational power have boosted the development and adoption of systems leveraging on high-resolution video recording to track an animal pose and describe behaviour in all four dimensions. However, the high temporal and spatial resolution that these systems offer must come as a compromise with their throughput and accessibility. Here we describe coccinella, an open-source reductionist framework combining high-throughput analysis of behaviour using real-time tracking on a distributed mesh of microcomputers (ethoscopes) with resource-lean statistical learning (HCTSA/Catch22). Coccinella is a reductionist system, yet outperforms state-of-the-art alternatives when exploring the pharmacobehaviour in Drosophila melanogaster.

neuroscience↗

bioRxiv2022

HAND1 knockdown disrupts trophoblast global gene expression

Congenital heart disease (CHD) affects nearly 1% of births annually, and CHD pregnancies carry increased risk of developing pathologies of abnormal placentation. We previously reported significant developmental impacts of disrupting Hand1, a gene associated with CHD, expression in placenta trophoblast and endothelial cells in multiple mouse models. In this study, we aimed to build upon this knowledge and characterize the mechanistic impacts of disrupting HAND1 on human placenta trophoblast and vascular endothelial cell gene expression. HAND1 gene expression was silenced in BeWo cells, a choriocarcinoma model of human cytotrophoblasts, (n=3-9 passages) and isolated human placental microvascular endothelial cells (HPMVEC; n=3 passages), with HAND1 siRNA for 96 h. Cells were harvested, mRNA isolated and RNA sequencing performed using the Illumina NextSeq 550 platform. Normalization and differential gene expression analyses were conducted using general linear modeling in edgeR packages. Statistical significance was determined using a log2 fold change of >1.0 or <-1.0 and unadjusted p-value [≤]0.05. Panther DB was used for overrepresentation analysis, and String DB for protein association network analysis. There was downregulation of 664 genes, and upregulation of 59 genes in BeWo cells with direct HAND1 knockdown. Overrepresentation analysis identified disruption to pathways including cell differentiation, localization, and cell projection organization. In contrast, only 7 genes were changed with direct HAND1 knockdown in HPMVECs. Disruption to HAND1 expression significantly alters gene expression profile in trophoblast but not endothelial cells. This data provides further evidence that future studies on genetic perturbations in CHDs should consider the extra-embryonic tissue in addition to the fetal heart.

genetics↗

bioRxiv2022

Placental treatment with insulin-like growth factor 1 via nanoparticle differentially impacts vascular remodeling factors in guinea pig sub-placenta/decidua

Clinically, fetal growth restriction (FGR) is only detectable in later gestation, despite pathophysiological establishment likely earlier in pregnancy. Additionally, there are no effective in utero treatment options for FGR. We have developed a nanoparticle to deliver human insulin-like 1 growth factor (hIGF-1) in a trophoblast-specific manner which results in increased expression of hIGF-1. IGF-1 signaling in the placenta regulates multiple developmental processes including trophoblast invasion and maternal vascular remodeling, both of which can be diminished in the FGR placenta. We aimed to determine the effects of short-term hIGF-1 nanoparticle treatment on sub-placenta/decidua trophoblast signaling mechanisms in FGR and under normal growth conditions. Using the guinea pig maternal nutrient restriction (MNR) model of FGR, ultrasound-guided, intra-placenta injections of hIGF-1 nanoparticle were performed at gestational day 30-33, and dams sacrificed five days later. Sub-placenta/decidua tissue was separated from placenta for further analyses. Western blot was used to analyze protein expression of ERK/AKT/mTOR signaling proteins (phospho-Erk (pErk), phospho-Akt (pAkt), raptor, rictor and deptor). qPCR was used to analyze gene expression of vascular/remodeling factors (vascular endothelial growth factor (Vegf), placenta growth factor (Pgf), platelet-derived growth factor (Pdgf)) and tight junction/adhesion proteins (claudin 5 (Cldn5), p-glycoprotein (Abcb1), occludin (Ocln) and tight junction protein 1 (Zo1)). MNR reduced expression of pErk, PdgfB and Cldn5, and increased expression of Ocln and Zo1 in the sub-placenta/decidua. In MNR + hIGF1 nanoparticle sub-placenta/decidua, expression of PdgfB, Ocln and Zo1 was normalized, whilst pAkt, VegfB, Vegf receptor 1 and PdgfB receptor were increased compared to MNR. In contrast, hIGF-1 nanoparticle treatment of normal placentas reduced expression of pErk, raptor and increased expression of the mTOR inhibitor deptor. This was associated with reduced expression of VegfA, Plgf, and PdgfB. Here we have shown that the impact of hIGF-1 nanoparticle treatment is dependent on pregnancy environment. Under MNR/FGR, hIGF-1 nanoparticle treatment triggers increased expression of growth factors and normalization of EMT factors. However, under normal conditions, the response of the placenta is to decrease AKT/mTOR signaling and growth factor expression to achieve homeostasis.

physiology↗

bioRxiv2022

Placental nanoparticle gene therapy normalizes gene expression changes in the fetal liver associated with fetal growth restriction in a fetal sex-specific manner

Fetal growth restriction (FGR) is associated with increased risk of developing Non-Communicable Diseases. We have a placenta-specific nanoparticle gene therapy protocol that increases placental expression of human insulin-like growth factor 1 (hIGF-1), for the treatment of FGR in utero. We aimed to characterize the effects of FGR on hepatic gluconeogenesis pathways during early stages of FGR establishment, and determine whether treatment of the placenta with nanoparticle mediated hIGF-1 therapy could resolve differences in the FGR fetus. Female Hartley guinea pigs (dams) were fed either a control or maternal nutrient restriction (MNR) diet using established protocols. At GD30-33, dams underwent ultrasound guided, transcutaneous, intra-placental injection of hIGF-1 nanoparticle or PBS (sham), and were sacrificed 5 days post-injection. Fetal liver tissue was fixed and snap frozen for morphology and gene expression analysis. In female and male fetuses, liver weight as a percentage of body weight was reduced by MNR, and not changed with hIGF-1 nanoparticle treatment. In female fetal livers, expression of hypoxia inducible factor 1 (Hif1) and tumor necrosis factor (Tnf) were increased in MNR compared to Control, but reduced towards Control in MNR + hIGF-1 livers. In male fetal liver, MNR increased expression of Igf-1, and decreased expression of Igf-2 compared to Control. Igf-1 and Igf-2 expression was restored to Control levels in the MNR + hIGF-1 group. This data provides further insight into the sex-specific mechanistic adaptations seen in FGR fetuses, and demonstrates that disruption to fetal developmental mechanisms may be returned to normal by treatment of the placenta.

physiology↗

bioRxiv2022

Replicative ageing perturbs the metabolic signature of murine C2C12 skeletal myotubes

IntroductionChronological ageing is associated with mitochondrial dysfunction and increased reactive oxygen species (ROS) production in skeletal muscle. However, the effects of replicative ageing on skeletal muscle cellular metabolism are not well known. Using an established myoblast model of cellular (replicative) ageing, we investigated the impact of ageing on energy metabolism in murine C2C12 myotubes. MethodsControl (P7-11) and replicatively aged (P48-51) C2C12 myoblasts were differentiated over 72-120 h. Mitochondrial bioenergetics were investigated by respirometry and mitochondrial superoxide and cellular ROS were measured in the absence and presence of antimycin A (AA). Genes related to mitochondrial remodelling and the antioxidant response were quantified by RT-qPCR. Intracellular metabolites were quantified using an untargeted 1H-NMR metabolomics pipeline. ResultsMitochondrial coupling efficiency (Control: 79.5 vs. Aged: 70.3%, P=0.006) and relative oxidative ATP synthesis (Control: 48.6 vs. Aged: 31.7%, P=0.022) were higher in control vs. aged myotubes, but rates of mitochondrial superoxide production were lower (Control: 2.4x10-5 {+/-} 0.4 x 10-5 vs. Aged: 9.7x10-5 {+/-} 1.6x10-5 RFU/sec/cell; P=0.035). Replicatively aged myotubes had greater mRNA expression of mfn2 and Tfam compared to control. Yet, Nrf2 and PGC-1 expression were 2.8-fold and 3.0-fold higher in control versus aged myotubes over 24 h and 48 h (P<0.05), respectively. Branched chain amino acids L-leucine, L-isoleucine and L-valine, and L-carnitine were less abundant in aged versus control myotubes. Conclusion(s)Replicative ageing is associated with bioenergetic uncoupling, increased ROS production and impaired amino acid metabolism. Our findings suggest that cellular mitochondrial dysfunction and altered energy metabolism may exacerbate the age-related decline in skeletal muscle mass and function.

cell biology↗

bioRxiv2022

Analysis of commonly expressed genes between first trimester fetal heart and placenta cell types in the context of congenital heart disease

Congenital heart disease (CHD) is often associated with fetal growth abnormalities. During the first trimester of pregnancy, the heart and placenta develop concurrently, and share key developmental pathways. Hence, it is hypothesized that defective morphogenesis of either organ is synergistically linked. However, many studies determined to understand the mechanisms behind CHD overlook the contribution of the placenta. In this study, we aimed to identify commonly expressed genes between first trimester heart and placenta cells using two publicly available single cell sequencing databases. Using a systematic computational approach, we identified 328 commonly expressed genes between heart and placenta endothelial cells and enrichment in pathways including Vasculature Development (GO:0001944, FDR 2.90E-30), and Angiogenesis (GO:0001525, FDR 1.18E-27). We also found, in comparison with fetal heart endothelial cells, 197 commonly expressed genes with placenta extravillous trophoblasts, 128 with cytotrophoblasts and 80 with syncytiotrophoblasts, and included genes such as FLT1, GATA2, ENG and CDH5. Finally, comparison of first trimester cardiomyocytes and placenta cytotrophoblasts revealed 53 commonly expressed genes and enrichment in biological processes integral to cellular function including Cellular Respiration (GO:0045333; FDR 5.05E-08), Ion Transport (GO:0006811; FDR 2.08E-02), and Oxidation-Reduction Process (GO:0055114; FDR 1.58E-07). Overall, our results identify specific genes and cellular pathways common between first trimester fetal heart and placenta cells which if disrupted may concurrently contribute to the developmental perturbations resulting in CHD.

genetics↗

bioRxiv2021

Identifying target sites for placental therapeutics through the comparison of normal term pregnancies and intrauterine growth restricted proteomes

A variety of pathologies, including intrauterine growth restriction (IUGR), have been linked to placental insufficiencies as important causal factors, however, little has been done to develop therapeutics that may improve placental development, structure and function. The placenta offers the opportunity to manipulate the in-utero environment without directly intervening with the fetus, accessible from the maternal circulation, a vital but temporary organ, the placenta is no longer required after birth. Developing therapeutics must involve multiple aspects of targeting and safety to ensure no off-target impact on the pregnant person or fetus as well as enhance efficiency of delivery. In addition to our studies on nanoparticle delivery to the placenta [1] we are developing targeting strategies to allow peripheral delivery via the maternal circulation. In this study we have performed the isolation of the microvillous membrane from human placental syncytiotrophoblast (the targeting cell) and via proteomic analysis identified potential targeting moieties, we have then compared this to publicly available data from pregnancies complicated by fetal growth restriction to ensure that we do not identify targets which would be reduced in FGR, resulting in less efficient targeting. HighlightsO_LIProteomic analysis detected key genes, proteins, and pathways present in the syncytiotrophoblast membrane of normal placentas. C_LIO_LISpecific membrane proteins identified show promise for future characterization of placental pathologies, such as IUGR. C_LIO_LIProteomes of normal and diseased placentas require further study to better understand the etiology of certain conditions. C_LI

bioinformatics↗

bioRxiv2021

Nanoparticle-mediated transgene expression of insulin-like growth factor 1 in the guinea pig placenta differentially affects fetal liver gene expression depending on maternal nutrient status

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 (hIGF-1) to correct fetal growth trajectories. Using the maternal nutrient restriction (MNR) guinea pig model of FGR, an ultrasound-guided, intra-placental injection of non-viral, polymer-based nanoparticle gene therapy containing plasmid with the hIGF-1 gene and placenta-specific Cyp19a1 promotor was administered at mid-pregnancy. Sustained hIGF-1 expression was confirmed in the placenta five days after treatment. Whilst gene therapy treatment 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, nanoparticle gene therapy treatment increased the fetal capillary volume density in the placenta, and reduced interhaemal distance between maternal and fetal circulation. Overall, our findings, that gene therapy treatment 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.

physiology↗

bioRxiv2021

Pharmacologically induced weight loss is associated with distinct gut microbiome changes in obese rats

BackgroundObesity, metabolic disease and some psychiatric conditions are associated with changes to relative abundance of bacterial species and specific genes in the fecal microbiome. Little is known about the impact of pharmacologically induced weight loss on distinct gut microbiome species and their respective gene programs in obese individuals. ResultsUsing shotgun metagenomics, the composition of the microbiome was obtained for two cohorts of obese female Wistar rats (n=10-12, total of 82) maintained on a high fat diet before and after a 42-day treatment with a panel of four investigatory or approved anti-obesity drugs (tacrolimus/FK506, bupropion, naltrexone and sibutramine), alone or in combination. We found that sibutramine treatment induced consistent weight loss through reducing food intake. Decreased weight loss in sibutramine-treated rats was associated with changes to the gut microbiome that included increased beta-diversity, increased Bacteroides/Firmicutes ratio and increased relative abundance of multiple Bacteroides species. In addition, the relative abundance of multiple genes was found to be differentially abundant, including significant reductions in components of flagellum and genes involved in flagellum assembly. ConclusionsThis study provides a large resource comprising complete shotgun metagenomics datasets of the fecal microbiome coupled with weight change and food intake at day 3, day 15 and day 42 from 82 obese rats treated with a range of compounds used for weight loss, which are available to the community for detailed analysis. Furthermore, by conducting a detailed analysis of the microbiome associated with sibutramine-induced weight loss, we have identified multiple weight-loss associated microbial taxa and pathways. These include a reduction in components of flagellum and the flagellum assembly pathway that points to a potential role of sibutramine-induced weight-loss on regulating bacterially driven anti-inflammatory responses.

genomics↗