Vascular Development Research Articles

Abstract 4135035: Liver kinase B1 (LKB1) loss links vascular smooth muscle cell fate switch to aortic aneurysm formation

Background: Acquisition and maintenance of vascular smooth muscle cell (VSMC) fate are important for vascular development and homeostasis; however, little is known about the key determinant for VSMC fate and vascular homeostasis. Methods: Lkb1 flox/flox ; Tagln- Cre, Lkb1 flox /flox ; Myh11-Cre/ERT2 , and lineage tracing Lkb1 flox/flox ; Myh11-Cre/ERT2 ; ROSA mT/mG mice were generated to study the impact of Lkb1 on VSMC and vascular function in vivo . Single aortic cells isolated from wild-type and Lkb1 flox/flox ; Myh11-Cre/ERT2 mice were analyzed by single-cell RNA sequencing (sc-RNA seq). The dynamic changes of vascular morphology and VSMC fate were investigated using high-frequency ultrasound and various histological techniques. In addition, VSMC phenotype and molecular mechanisms were further explored by mouse arterial ring assay ex vivo , in cultured human aortic VSMC in vitro, and in human aneurysmal aortic tissues. Results: We found that SMC-specific Lkb1 ablation in Lkb1 flox/flox ; Tagln-Cre mice caused severe vascular abnormalities and embryonic lethality. SMC-specific deletion of Lkb1 in tamoxifen-inducible Lkb1 flox/flox ; Myh11-Cre/ERT2 mice spontaneously and progressively induced aortic/arterial dilation, aneurysm, rupture, and premature death. Sc-RNA seq and imaging-based lineage tracing showed that Lkb1 -deficient VSMCs transdifferentiated gradually from early modulated VSMCs to fibroblast-like and chondrocyte-like cells, leading to ossification and blood-vessel rupture. Moreover, we found that SMC-specific Lkb1 ablation resulted in decreased vascular contractility and hypotension in vivo . Mechanistically, Lkb1 regulates polypyrimidine tract binding protein 1 (Ptbp1) expression and controls alternative splicing of pyruvate kinase muscle (PKM) isoforms 1 and 2. Lkb1 loss in VSMC results in an increased PKM2/PKM1 ratio and alters the metabolic profile by promoting aerobic glycolysis. Treatment with PKM2 activator TEPP-46 rescues VSMC transformation and aortic dilation in Lkb1 flox/flox ; Myh11-Cre/ERT2 mice. Furthermore, we found that Lkb1 expression decreased in human aortic aneurysm tissue compared to control tissue, along with changes in markers of VSMC fate. Conclusions: Lkb1, via its regulation of Ptbp1-dependent alterative splicing of PKM, maintains VSMC in contractile states and sustains vascular homeostasis. Our findings have important implications for understanding the pathogenesis of aortic aneurysm.

Protein Biomarkers of Adverse Clinical Features and Events in Sarcomeric Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a heterogeneous condition that can lead to atrial fibrillation, heart failure, and sudden cardiac death in many individuals but mild clinical impact in others. The mechanisms underlying this phenotypic heterogeneity are not well defined. The aim of this study was to use plasma proteomic profiling to help illuminate biomarkers that reflect or inform the heterogeneity observed in HCM. The Olink antibody-based proteomic platform was used to measure plasma proteins in patients with genotype positive (sarcomeric) HCM participating in the HCM Registry. We assessed associations between plasma protein levels with clinical features, cardiac magnetic resonance imaging metrics, and the development of atrial fibrillation. We measured 275 proteins in 701 patients with sarcomeric HCM. There were associations between late gadolinium enhancement with proteins reflecting neurohormonal activation (NT-proBNP [N-terminal pro-B-type natriuretic peptide] and ACE2 [angiotensin-converting enzyme 2]). Metrics of left ventricular remodeling had novel associations with proteins involved in vascular development and homeostasis (vascular endothelial growth factor-D and TM [thrombomodulin]). Assessing clinical features, the European Society of Cardiology sudden cardiac death risk score was inversely associated with SCF (stem cell factor). Incident atrial fibrillation was associated with mediators of inflammation and fibrosis (MMP2 [matrix metalloproteinase 2] and SPON1 [spondin 1]). Proteomic profiling of sarcomeric HCM identified biomarkers associated with adverse imaging and clinical phenotypes. These circulating proteins are part of both established pathways, including neurohormonal activation and fibrosis, and less familiar pathways, including endothelial function and inflammatory proteins less well characterized in HCM. These findings highlight the value of plasma profiling to identify biomarkers of risk and to gain further insights into the pathophysiology of HCM.

Mechanism of CXCL8 regulation of methionine metabolism to promote angiogenesis in gliomas

BackgroundGliomas are the most common malignant brain tumors characterized by angiogenesis and invasive growth. A detailed understanding of its molecular characteristics could provide potential therapeutic targets. In the present study, we sought to explore the key gene CXCL8 in methionine metabolism in gliomas and its potential role in angiogenesis.MethodsU251 glioma cells were divided into control and methionine-restriction tolerant (constructed with 1/4 of the standard level of methionine in the culture medium) groups for transcriptome and metabolome analysis. To confirm the functions and mechanism of CXCL8 in glioma, heat map, volcano map, Go enrichment, gene set enrichment analysis (GSEA), protein–protein interaction network analysis, RT-PCR, western blotting assays, chicken embryo chorioallantoic membrane (CAM) test, chicken embryo yolk sac membrane (YSM) test and transplantation tumor nude mice model were performed. The TCGA database, CGGA database and clinical tissue samples were used to analyze CXCL8’s significance on prognosis for patients with glioma.ResultsCXCL8 expression was significantly up-regulated in methionine-restricted tolerance cells, it also activated vascular system development and triggered angiogenesis. CXCL8 expression is negatively correlated with survival prognosis in gliomas.ConclusionsGlioma cells promote angiogenesis in methionine-restricted environments through the activation of CXCL8, compensating for nutrient deprivation, and possibly contributing to the failure of antiangiogenic therapy.

Bax expression impacts postnatal retinal vascular development and hyperoxia sensitivity

Apoptosis plays prominent roles during organ development, maturation and homeostasis. In the retina, Bcl-2 family members function through the intrinsic cell death pathway with vital roles during vascular development and hyperoxia-mediated vessel obliteration during oxygen induced ischemic retinopathy (OIR). Bim, a BH3 only protein Bcl-2 family member, binds and activates Bax and/or Bak to facilitate apoptosis. In some systems deletion of both Bax and Bak are required to prevent cell loss, such as regression of ocular hyaloid vasculature. We previously showed Bim expression significantly impacts normal retinal vascular development and sensitivity to hyperoxia. Mice deficient in Bim (Bim-/-) show increased retinal vascular density and are protected from hyperoxia mediated vessel obliteration. Since Bim activates Bax, here we determined the impact lack of Bax expression has on these processes. Compared to Bax+/+ mice, retinas from Bax-/- mice had significantly increased numbers of retinal endothelial cells and pericytes. We also demonstrated that hyperoxia-mediated vessel obliteration during OIR was significantly decreased in the absence of Bax. Although the increased endothelial cell numbers were comparable to that of Bim-/- mice, the increased numbers of pericytes were not to the extent noted in Bim-/- mice. These changes were supported by partial protection of retinal vessels from hyperoxia in Bax-/- mice compared to that noted in Bim-/- mice. Thus, Bim-Bax driven pathway is sufficient to remove excess endothelial cells but not pericytes during postnatal retinal vascularization and hyperoxia-mediated vessel obliteration. Thus, additional Bim-mediated pathway(s) are required for removal of pericytes and hyperoxia-mediated vessel obliteration.

Inhibition of lysophosphatidic acid receptor 2 attenuates neonatal chronic lung disease in mice by preserving vascular and alveolar development

AimBronchopulmonary dysplasia (BPD) is a common morbidity in extremely premature infants. Previous studies demonstrated the important role of lysophosphatidic acid (LPA) in inflammation in BPD. However, the role of LPA and its receptors in hyperoxia-induced vascular malformations in BPD remains to be elucidated. Methods and ResultsElevated plasma LPA levels were observed in mice with BPD compared to controls (792 vs. 607 ng/mL, p < 0.05). Inhibition of LPA signaling protected against hyperoxia-induced lung injury in neonatal mice, demonstrated by a 2.8-fold increase in pulmonary vascular density and a 14% reduction in alveolar enlargement. In vitro studies showed that LPA suppressed tube formation in human umbilical vein endothelial cells (HUVECs) by approximately 50%. LPA receptor 2 (LPA2) was identified as a functional LPA receptor in primary endothelial cells from the lungs of hyperoxic mice and in HUVECs under hyperoxic conditions. The LPA2 antagonist H2L5186303 enhanced the tube formation ability of HUVECs exposed to LPA, both under normoxia (4-fold) and hyperoxia (5-fold). Moreover, H2L5186303 significantly protected against hyperoxia-induced vascular malformation (2-fold) and improved alveolarization in neonatal mice (12% decrease in mean linear intercept, MLI). Early growth response 1 (EGR1) was characterized as a downstream target of LPA2, silencing EGR1 restored tube formation in HUVECs exposed to LPA and hyperoxia. ConclusionsOur in vitro and in vivo findings demonstrate that the inhibition of LPA/LPA2 signaling mitigates hyperoxia-induced pulmonary vascular malformations, suggesting the LPA/LPA2-dependent signaling pathway has therapeutic potential for extremely premature infants with BPD.

Endomucin regulates the endothelial cytoskeleton independently of VEGF

The endothelial glycocalyx, lining the apical surface of the endothelium, is involved in a host of vascular processes. The glycocalyx is comprised of a network of membrane-bound proteoglycans and glycoproteins along with associated plasma proteins. One such glycoprotein is endomucin (EMCN), which our lab has revealed is a modulator of VEGFR2 function. Intravitreal injection of siEMCN into the eyes of P5 mice impairs vascular development. In vitro silencing of EMCN suppresses VEGF-induced proliferation and migration. Signaling pathways that drive cell migration converge on cytoskeletal remodeling. By coupling co-immunoprecipitation with liquid chromatography/mass spectrometry, we identified interactions between EMCN and proteins associated with actin cytoskeleton organization. The aim of the study was to investigate the influence of EMCN on cytoskeleton dynamics in angiogenesis. EMCN depletion resulted in reduction of F-actin levels, whereas overexpression of EMCN induced increased membrane protrusions in cells that were rich in stress fibers. The reorganization of the actin filaments did not depend on VEGFR2 signaling, suggesting that EMCN connects the cytoskeleton and the glycocalyx.

Maternal Supplementation Spermidine During Gestation Improves Placental Angiogenesis and Reproductive Performance of High Prolific Sows.

Spermidine (SPD) is a widely recognized polyamine compound found in mammalian cells and plays a key role in various cellular processes. We propose that SPD may enhance placental vascular development in pregnant sows, leading to increased birth weight of piglets. Six hundred and nine sows at 60 days of gestation were randomly assigned into a basal diet (CON group), basal diet supplemented 10 mg/kg of SPD (SPD1 group), and basal diet supplemented 20 mg/kg of SPD (SPD2 group), respectively. Compared with the CON, SPD1 significantly increased the average number of healthy piglets per litter and the placental efficiency (P < 0.05), while the average number of mummified fetus per litter and the percentage of weak piglets significantly decreased (P < 0.05). In the plasma metabolomics, SPD content in plasma of sows (P = 0.075) and umbilical cord plasma of piglets (P = 0.078) had an increasing trend in response to SPD1. Furthermore, SPD1 increased the expression of the vascular endothelial cell marker protein, platelet endothelial cell adhesionmolecule-1 (PECAM-1/CD31) and the density of placental stromal vessels (P < 0.05). Moreover, as compared to CON, SPD2 significantly decreased the average number of mummified fetus per litter (P < 0.05), while the placental efficiency and the expression of amino acid transporter solute carrier (SLC) family 7, member7 (SLC7A7) and glucose transporters SLC2A2) and SLC5A4 in placental tissue significantly increased (P < 0.05). These results suggest that maternal supplementation of SPD during pregnancy increased healthy litter number, and promoted placental tissue development. Our findings provide evidence that maternal SPD has the potential to improve the production performance of sows.

Multi-omics integration analysis identifies pathogenic candidate genes of congenital heart defects with vascular malformation

Abstract Background Congenital heart defects (CHD) with vascular malformation harbors numerous genetic and epigenetic aberrations of DNA copy numbers and methylation. Proteomic deregulation by the aberrations plays key driver roles in heterogeneous progression of CHD. However, it still remains largely unknown about integrative analysis of genetic, epigenetic regulation and proteome in CHD. Purpose We employed a multi-omics approach to explore pathogenic candidate genes in CHD with vascular malformation. Methods Previously, we gathered WES data for 216 CHD patients with vascular malformation and 100 healthy controls. Meanwhile, we carried out DNA methylation analysis from 11 patients and 5 controls. Here, we profile proteomics of vascular tissues from 11 patients and 5 controls. Integration analysis of DNA copy-number-correlated (CNVcor) genes, methylation-correlated (METcor) genes and differentially proteins reveal the innovative and crucial pathogenetic genes. We then detected spatiotemporal expression patterns of candidate genes in zebrafish embryos using in situ hybridization and qPCR, and verified the roles in vascular development by morpholino-mediated gene knockdown. Results 90 differentially expressed proteins (DEPs) were obtained using proteomics and were mainly related to cell adhesion and migration, angiogenesis, amino acid metabolism, and HIF-1 signaling pathway through GO and KEGG pathway enrichment analysis. 15 hub proteins were identified by WGCNA analysis (Fig 1). Additionally, we found that the frequencies of the aberrancies of the CNVcor genes were significantly correlated with the METcor genes (Fig 2 C). We obtained 1924 differentially CNVcor genes and 952 differentially METcor genes. Then, we computed the Pearson’s correlation coefficients of all three-omics by pairwise comparison and found that the distribution of correlations was bimodal (Fig 2 D). Meanwhile, 28 overlapped genes were observed among three-omics. We screened out 11 candidate genes (TIMP1, BGN, LTBP1, AKR1C3, LOXL3, MAOA, MAOB, GNA12, IFI30, CNTNAP1, IGF2BP1) according to the node degree of PPI network analysis between 28 genes and known vascular development related genes. We further figured out LOXL3, MAOA, CNTNAP1 and IGF2BP1 are the novel important genes for vascular malformation, of which CNTNAP1 is the joint gene of three-omics. Through expression patterns and gene knockdown in zebrafish embryos, we revealed that LOXL3, MAOA, CNTNAP1 and IGF2BP1 affect vascular development (Fig 2 E-G). Conclusions We identify novel key candidate genes (LOXL3, MAOA, CNTNAP1 and IGF2BP1) potentially related to CHD with vascular malformation and elucidate the possible molecular pathogenesis of CHD. Our multi-omics integrative analysis provides new insights on the multi-layered etiology of CHD, which might be helpful in developing clinical diagnosis and precaution for CHD.Figure 1Figure 2

Impact of neonatal hyperoxia on the development of the coronary vascular bed: an experimental model for the study of cardiomyopathy associated with premature birth

Abstract Introduction Very preterm birth (PT; &amp;lt;32 weeks of gestation), nearly 2% of all births, leads to short-term complications such as bronchopulmonary dysplasia and retinopathy of prematurity that are driven by compromised organ vascular development. Adults born preterm display an increased risk of ischaemic cardiomyopathy and heart failure. Our group has shown that neonatal rats exposed to hyperoxia, simulating the PT neonatal conditions, develop cardiomyocytes hypertrophy, fibrosis and cardiac dysfunction, or Oxygen-Induced Cardiomyopathy (OIC). Whether cardiac changes also associate with alterations in vascular development in the left ventricle (LV) remains unknown. Purpose We hypothesized that neonatal exposure to hyperoxia impact the development of the LV vascular network. Methods Male pups were exposed to 80% O2 (OIC) or room air (CTRL) from day 3 (P3) to P10 of life. Hearts were collected at P10, 4- and 16 weeks. Arteriolar length and capillary density per cardiomyocyte were measured using stereology (elastin) and immunofluorescence (WGA, α-SMA, CD31). High-resolution 3D reconstruction of the vascular network was achieved by combining fluorescent labelling of coronaries (anti-α-SMA) and capillaries (anti-CD31) with a tissue-cleaning protocol (iDisco+), allowing detailed morphometric characterization of the vascular network. The expression of vascular endothelial growth factors and receptors (VEGFA, VEGFB, VEGFR 1 and 2, NRP1, and PIGF) were quantified by RT-qPCR and Western blots. Differences between groups were analyzed with Student's t-test (P &amp;lt; 0.05) (N = 6 per group). Results At P10, we observed a notable rise in the number of capillaries per cardiomyocyte (0.88 ± 0.05 vs. 0.62 ± 0.02 mm2) and a significant increase in VEGFA (+76%) and NRP1 (+38%) expression in the LV from OIC vs. CTRL rats. By 4 weeks, the OIC group showed a significant reduction in arteriolar length vs. CTRL (6.51 ± 0.76 vs. 9.77 ± 1.12 m/cm3), coupled with an increase in the number of capillaries per cardiomyocyte (1.11 ± 0.05 vs. 0.85 ± 0.03 mm2). VEGFA was decreased (-14%) and PLGF increased (+24%) in the LV of OIC rats. At 16 weeks, the OIC condition displayed a significant increase in the number of capillaries per cardiomyocyte (1.37 ± 0.03 vs. 0.98 ± 0.07 mm2) and a decrease in VEGFA (-23%), along with reduction in its receptors VEGFR1 (-27%), VEGFR2 (-20%) and NRP1 (-17%). Conclusion OIC resulting from neonatal hyperoxia exposure associates with vascular changes in the LV that persist to adulthood. These changes are characterized by a reduction in arteriolar length and an increase in the number of capillaries, accompanied by modulation of the expression of pro-angiogenic VEGFA and receptors. The impact of these vascular alterations on the susceptibility of the LV to ischemic or hypertension-related damage is to be explored. These findings suggest a crucial mechanistic pathway for understanding the risk of cardiac pathologies associated with preterm birth.

Role of semaphorins, neuropilins and plexins in cancer progression

Progress in understanding nervous system-cancer interconnections has emphasized the functional role of semaphorins (SEMAs) and their receptors, neuropilins (NRPs) and plexins (PLXNs), in cancer progression. SEMAs are a conserved and extensive family of broadly expressed soluble and membrane-associated proteins that were first described as regulators of axon guidance and neural and vascular development. However, recent advances have shown that they can have a dual role in cancer progression, acting either as tumor promoters or suppressors. SEMAs effects result from their interaction with specific co-receptors/receptors NRPs/PLXNs, that have also been described to play a role in cancer progression. They can influence both cancer cells and tumor microenvironment components modulating various aspects of tumorigenesis such as oncogenesis, tumor growth, invasion and metastatic spread or treatment resistance. In this review we focus on the role of these axon guidance signals and their receptors and co-receptors in various aspects of cancer. Furthermore, we also highlight their potential application as novel approaches for cancer treatment in the future.

Expression of cardiomyopathy-related genes in mononuclear blood cells predicts all-cause mortality in patients presenting with acute versus chronic coronary syndrome requiring revascularisation

Abstract Objective Despite advances in the revascularisation techniques their net clinical benefit differs substantially between patients presenting with myocardial infarction (ACS) and chronic coronary syndrome (CCS) due to obstructive coronary atherosclerosis. Considering that leukocytes represents a key pathophysiological component of myocardial ischaemia, exploration of mononuclear blood cell (PBMC) gene expression profile in CCS and ACS setting could reveal clinically relevant transcriptomic signals. The aim of the present study was to identify differences in PBMC transcriptome between ACS and CCS patients which are linked to mortality after revascularisation. Methods and Results We analysed PBMC transcriptomes from719 ACS and 486 CCS patients creating discovery cohort. The results of transcriptomic analysis were verified in replication cohort (ACS: N=682 for CCS: N=489) generated based on propensity score matching. Median time from revascularisation to blood collection (IQR) was 15.68 (-4.52, 23.23) hrs. Patients with ACS showed consistent differential expression of 8173 genes (4544 upregulated, 3629 downregulated) when compared with CCS patients. The subsequent pathway analysis also showed significant enrichment of several canonical pathways involved in major cardiovascular pathologies i.e. atherosclerosis (p = 1.22-06, enrichment = 3.39), vascular endothelial growth factor production (p = 1.16-06, enrichment = 16.73), positive regulation of vascular development (p = 2.78-06, enrichment = 5.30) and heterotopic cell adhesion including gene desmocollin 2 (DSC2, p = 3.64-04, enrichment = 6.30). In der multivariate survival analysis with differentially expressed genes, increased expression of DCS2, lamin A/C (LMNA), and UGGT2, and decreased expression of SNRNP70 predicted poor survival over the median follow-up 11.35 yrs. Consistently, controlling the false discovery rate at ≤ 5% these genes enriched pathways involved in cardiomyopathies such as arrhythmogenic right-ventricular cardiomyopathy (p = 4.19x10-4, enrichment = 58.9) and collagen disease (p = 2.29x10-3, enrichment = 23.8). Conclusion We found altered PBMC expression of multiple genes in patients requiring revascularisation for ACS versus CCS. Several differentially expressed genes included in cardiomyopathy pathways predicted long-term all-cause mortality in these patients.

Sulforaphane Attenuates Ethanol-Induced Teratogenesis and Dysangiogenesis in Zebrafish Embryos

Prenatal ethanol exposure can cause a broad range of abnormalities in newborns known as Fetal Alcohol Spectrum Disorder (FASD). Despite significant progress in understanding the disease mechanisms of FASD, there remains a strong global need for effective therapies. To evaluate the therapeutic potential of sulforaphane (SFN), an active compound extracted from cruciferous vegetables, in preventing FASD, ethanol-exposed zebrafish embryos were pretreated, co-treated, or post-treated with various concentrations of SFN. The FASD-like morphological features, survival rate, hatching rate, and vascular development were then assessed in the zebrafish embryos. It was found that pretreatment with 2 μM SFN during 3–24 hpf had no noticeable protective effects against teratogenicity induced by subsequent 1.5% ethanol exposure during 24–48 hpf. In contrast, co-treatment with 2 μM SFN and 1.5% ethanol during 3–24 hpf significantly alleviated a range of ethanol-induced malformations, including reduced body length, small eyes, reduced brain size, small otic vesicle, small jaw, and pericardial edema. Post-treatment with 3 μM SFN for 4 days following 1.5% ethanol exposure during 3–24 hpf also significantly reduced the characteristic features of FASD, decreasing the mortality rate and restoring body length, eye size, brain size, and otic vesicle circumference. Moreover, we found that ethanol, even at a low dose (0.5%), causes vascular development deficit in the zebrafish embryos, which were also largely rescued by SFN treatment. These data indicated that SFN has great potential to be used in the prevention and treatment of FASD.

Vitamin C supplementation improves placental function and alters placental gene expression in smokers

Maternal smoking during pregnancy (MSDP), driven by nicotine crossing the placenta, causes lifelong decreases in offspring pulmonary function and vitamin C supplementation during pregnancy prevents some of those changes. We have also shown in animal models of prenatal nicotine exposure that vitamin C supplementation during pregnancy improves placental function. In this study we examined whether vitamin C supplementation mitigates the effects of MSDP on placental structure, function, and gene expression in pregnant human smokers. Doppler ultrasound was performed in a subset of 55 pregnant smokers participating in the “Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function” (VCSIP) randomized clinical trial (NCT01723696) and in 33 pregnant nonsmokers. Doppler ultrasound measurements showed decreased umbilical vein Doppler velocity (Vmax) in placebo-treated smokers that was significantly improved in smokers randomized to vitamin C, restoring to levels comparable to nonsmokers. RNA-sequencing demonstrated that vitamin C supplementation to pregnant smokers was associated with changes in mRNA expression in genes highly relevant to vascular and cardiac development, suggesting a potential mechanism for vitamin C supplementation in pregnant smokers to improve some aspects of offspring health.

Indole-3-Acetic Acid (IAA) and Sugar Mediate Endosperm Development in Rice (Oryza sativa L.)

The yield potential of large-panicle rice is often limited by grain-filling barriers caused by the development of inferior spikelets (IS). Photoassimilates, which are the main source of rice grain filling, mainly enter the caryopsis through the dorsal vascular bundle. The distribution of assimilates between superior spikelets (SS) and IS is influenced by auxin-mediated apical dominance; however, the mechanism involved is still unclear. In this study, the effect of auxin signaling on the grain filling of SS and IS was investigated in two large-panicle japonica rice varieties, W1844 and CJ03. Compared to SS, IS displayed delayed initiation of filling and a significantly lower grain weight. Furthermore, the endosperm development in IS remained stagnant at the coenocytic stage. The development of the dorsal vascular bundle in the IS was also slow, and poor sucrose-unloading was observed during the initial grain filling stage. However, the endosperm development in IS immediately started after the improvement of dorsal vascular bundle development. GUS activity staining further revealed that indole-3-acetic (IAA) was localized in the dorsal vascular bundle and surrounding areas, suggesting that the low IAA content observed in the IS during the initial grain filling stage may have delayed the development of the dorsal vascular bundle. Therefore, these results demonstrate that IAA may control sugar transport and unloading by regulating dorsal vascular bundle development, consequently affecting endosperm development in IS.

Transcriptomic Remodeling Occurs During Cambium Activation and Xylem Cell Development in Taxodium ascendens

Taxodium ascendens has been extensively cultivated in the wetlands of the Yangtze River in south China and has significantly contributed to ecology and timber production. Until now, research on T. ascendens genomics has yet to be conducted due to its large and complex genome, which hinders the development of T. ascendens genomic resources. Combined with the microstructural changes during cambium cell differentiation across various growth periods, we investigate the transcriptome expression and regulatory mechanisms governing cambium activity in T. ascendens. Using RNA sequencing (RNA-Seq) technology, we identified the genes involved in the cambium development of cells at three stages (dormancy, reactivation, and activity). These genes encode the regulatory and control factors associated with the cambial activity, cell division, cell expansion, and biosynthesis of cell wall components. Blast comparison revealed that three genes (TR_DN69961_c0_g1, TRINITY_DN17100_c1_g1, TRINITY_DN111727_c0_g1) from the MYB and NAC families might regulate transcription during lignin formation in wood thickening. These results illustrate the dynamic changes in the transcriptional network during vascular cambium development. Additionally, they shed light on the genetic regulation mechanism of secondary growth in T. ascendens and guide further elucidation of the candidate genes involved in regulating cambium differentiation and wood formation.

Comparative transcriptomic analysis validates iPSC derived in-vitro progressive fibrosis model as a screening tool for drug discovery and development in systemic sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, immune dysregulation, and systemic fibrosis. Research on SSc has been hindered largely by lack of relevant models to study the progressive nature of the disease and to recapitulate the cell plasticity that is observed in this disease context. Generation of models for fibrotic disease using pluripotent stem cells is important for recapitulating the heterogeneity of the fibrotic tissue and are a potential platform for screening anti-fibrotic drugs. We previously reported a novel in-vitro model for fibrosis using induced pluripotent stem cell-derived mesenchymal cells (iSCAR). Here we report the generation of a "scar-like phenotype" when iPSC derived mesenchymal cells are cultured on hydrogel that mimicks a wound healing/scarring response (iSCAR). First, we performed RNA sequencing (RNA-seq) based transcriptome profiling of iSCAR culture at 48h and 13days to characterize early and latestage scarring phenotypes. The next generation RNA-seq of these iSCAR culture at different timepoints detected expression 92% of early "scar associated" genes and 85% late "scar associated" genes, respectively. Comparative transcriptomic analysis of a gene level SSc compendium matrix to the iSCAR wound associated model revealed genes common in both data sets. Early scar formation genes showed biological processes of hypoxia (27.5%), vascular development (13.7%) and glycolysis (27.5), while late scar formation showed genes associated with senescence (22.6%). Next we show the effects of two different antifibrotic compounds to validate the utility of the model as a screening tool to study early and late-stagelate-stage fibrosis. An autotaxin inhibitor was used to validate the iSCAR late stage fibrotic model (iSCAR-T) and an antifibrotic tool screening compound of unknown mechanism (EX00015097) was used to study and validate both early (iSCAR-P) and late-stage (iSCAR-T) fibrosis in the iSCAR model.

PET Imaging Using 89Zr Labeled StarPEG Nanocarriers Reveals Heterogeneous Enhanced Permeability and Retention (EPR) in Prostate Cancer.

The enhanced permeability and retention (EPR) effect controls passive nanodrug uptake in tumors, and may provide a high tumor payload with prolonged retention for cancer treatment. However, EPR-mediated tumor uptake and distribution vary by cancer phenotype. Thus, we hypothesized that a companion PET-imaging surrogate may benefit EPR-mediated therapeutic drug delivery. We developed two 89Zr-radiolabeled nanocarriers based on 4-armed-starPEG40kDa with or without talazoparib (TLZ), a potent PARPi, as surrogates for the PEG-TLZ4 therapeutic scaffold. For PET imaging, PEG-DFB4 and PEG-DFB1-TLZ3 were radiolabeled with 89Zr by replacing one or all four TLZ on PEG-TLZ4 with deferoxamine B (DFB). The radiolabeled nanodrugs [89Zr]PEG-DFB4 and [89Zr]PEG-DFB1-TLZ3 were tested in vivo in prostate cancer subcutaneous xenografts (22Rv1, LTL-545, and LTL-610) and 22Rv1 metastatic models. Their EPR-mediated tumoral uptake and penetration was compared to CT26, a known EPR-high MicroPET/CT images, organ biodistribution, and calculated kinetic parameters showed high uptake in CT26 and LTL-545, moderate to low uptake in LTL-610 and 22Rv1. MicroPET/CT and high-resolution autoradiographic images showed nanocarrier penetration into highly permeable CT26, but heterogeneous peripheral accumulation was observed in LTL-545, LTL-610, and 22Rv1 subcutaneous xenografts and metastatic tumors. CD31 staining of tumor sections showed homogenous vascular development in CT26 tumors and heterogeneity in other xenografts. Both [89Zr]PEG-DFB4 and [89Zr]PEG-DFB1-TLZ3 showed similar accumulation and distribution in subcutaneous and metastatic tumor models. Both nanocarriers can measure tumor model passive uptake heterogeneity. Although heterogeneous, prostate cancer xenografts had low EPR. These starPEG nanocarriers could be used as PET imaging surrogates to predict drug delivery and efficacy.

Evaluation of an engineered vascular graft exhibiting somatic growth in lambs to model repair of absent pulmonary artery branch

BackgroundGrowth is the holy grail of tissue implants in pediatrics. No vascular graft currently in use for surgical repairs of congenital heart defects has somatic growth capacity.MethodsBiologically-engineered grafts (6 mm) grown from donor ovine fibroblasts in a sacrificial fibrin gel were implanted into the left pulmonary branch of 3-month old lambs for 3, 6, and 18 months. A control group of Propaten® PTFE grafts was implanted for 6 months.ResultsThe engineered grafts exhibit extensive site-appropriate recellularization after only 3 months and near-normal increase of diameter from the preimplant value of 6 mm to 12.9 mm and also a doubling of length from 6.0 mm to 13.0 mm at 6 months (n = 3) associated with apparent somatic graft growth (collagen content increase of 265% over 18-month, n = 2), along with excellent hemodynamics and no calcification, in contrast to the Propaten® grafts. The left-right flow distribution is nearly 50–50 for the engineered grafts at 6 months (n = 3) compared to about 20–80 for the Propaten® grafts (n = 3), which have less than one-half the diameter, a 6-fold higher pressure gradient, and stunted vascular development downstream of the graft. The engineered grafts exhibit a stable diameter over months 12–18 when the lambs become adult sheep (n = 2).ConclusionsThis study supports the use of these regenerative grafts with somatic growth capacity for clinical trial in patients born with a unilateral absent pulmonary artery branch, and it shows their potential for improving development of the downstream pulmonary vasculature.

Evaluating fetal pulmonary vascular development in congenital heart disease: a comparative study using the McGoon index and multiple parameters of fetal echocardiography.

The purpose of this study was to evaluate the value of MGI and multi-parameter in the assessment of different pulmonary circulation blood volumes in congenital heart disease. This study included 350 fetuses categorized into two groups: Normal group consisted of 258 fetuses with no discernible abnormalities through echocardiography as control Group A; Abnormal group with abnormal echocardiogram, including Group B of 71 fetuses with decreased pulmonary blood flow or pulmonary atresia and Group C of 21 fetuses with reduced or detached aortic blood flow. The MGI and Z-scores were measured and compared among these groups. Significant variations were noted in the aortic outflow Z-scores (AO-Zs) (p<0.01), pulmonary artery (PA) (p<0.01), PA Z-scores (PA-Zs) (p<0.01), PA/AO (p<0.01), right PA (p<0.01), and MGI (p<0.01) among the three groups (all p<0.05). Among fetuses with decreased pulmonary blood flow or pulmonary atresia, PA, PA-Zs, and MGI in fetuses with reverse DA flow perfusion were lower than those in the DA forward perfusion group. Fetal echocardiography, incorporating the MGI and multi-parameter, not only allows for the evaluation of pulmonary blood flow and pulmonary vascular development of the fetus but also enables the observation of changes in pulmonary blood flow and MGI development across different gestational weeks.

First-trimester maternal tryptophan metabolites, utero-placental (vascular)development and hypertensive disorders of pregnancy: The Rotterdam periconceptional cohort

BackgroundHypertensive disorders of pregnancy (HDP) are a significant cause of maternal and perinatal mortality and morbidity. Knowledge on the placenta-related pathophysiology of HDP is increasing. Since maternal tryptophan metabolites are involved in placentation, we investigated associations between first-trimester tryptophan metabolites and utero-placental (vascular) development, and the occurrence of HDP. Methods911 women were included from a prospective tertiary hospital cohort. Serum tryptophan metabolites were determined at 8.1 ± 1.4 weeks gestation. Placental volume (PV) and utero-placental vascular volume (uPVV) were determined at 7, 9 and 11 weeks gestation. HDP, including hypertension in early pregnancy, gestational hypertension, and preeclampsia, were retrieved from medical records. Associations with PV- and uPVV-trajectories were assessed using mixed models, and HDP risks were estimated by logistic regression models, adjusted for confounders. A mediation analysis was performed to evaluate whether blood pressure was a mediator in the associations with utero-placental (vascular) development. ResultsA negative association between kynurenine and PV-trajectories was found (β = −0.129, 95%CI = −0.220 to –0.039), which was not mediated by blood pressure. No significant associations between other tryptophan metabolites and PV- and uPVV-trajectories were observed. Higher 5-hydroxytryptophan was associated with hypertension in early pregnancy (OR = 1.405, 95%CI = 1.210–1.681), and with an increased risk of preeclampsia in these women. No associations between tryptophan metabolites and other HDP were found. ConclusionsHigher first-trimester kynurenine concentrations were associated with impaired utero-placental (vascular) development. Higher first-trimester 5-hydroxytryptophan concentrations were associated with early pregnancy hypertension, and an increased risk of preeclampsia, indicating its clinical potential as biomarker for future prediction, prevention and treatment of HDP.