Regulation Of Development Research Articles

Safety and security co-analysis in transport systems: Current state and regulatory development

• The framework is proposed using security-driven and safety-oriented methods. • SSCA is constructed through both top-down and bottom-up perspectives. • The regulatory development of SSCA is analysed among different transport modes. • It strikes new research directions for digitalised and autonomous transport vehicles. Transportation is sensitive to risk. Given the fast development of digitalisation and automation of transport systems in the past decade, new types of security risks (e.g. cyberattacks) emerge within the context of transport safety research. To enable the integrated analysis of emerging security and classical safety-related risks in a holistic manner, safety and security co-analysis (SSCA) is highly demanded for accident prevention. SSCA in transport systems will benefit the risk analysis of complex cyber physical transport systems facing challenges from both hazards and threats. However, the nature of hazard and threat-based risks is fundamentally different, which leads to the various difficulties of analysing them on the same plane. They include the use of different risk parameters, the uncertainty levels of the risk input and the methodologies of risk inference. To address such concerns, this study firstly reviews the literature on SSCA and compares the employed methodologies and their applications within the context of transport systems. Taking into account the advantages of both security-driven and safety-oriented methods, a conceptual framework is proposed to imply the insights on SSCA for transportation through both top-down and bottom-up perspectives, followed by a quantitative illustrative case study. Then, the regulatory development and evolution of SSCA in transport in practice is analysed across different transport modes, which configures initiatives’ interrelations for a cross-fertilisation purpose. As a result, the findings reveal new research directions for the safety of digitalised and/or autonomous transport vehicles and aid in the formation of future transport safety study agendas.

Laboratory and field studies to ensure the regulatory framework development and the transport facilities’ safety in the wave effect conditions

This article is part of the author’s dissertation research in the field of scientific substantiation of the development and improvement of the regulatory framework for ensuring the safety of transport facilities in conditions of wave effect. The article deals with such transport structure elements as bridge piers and railway roadbeds, which are located on the shores of the seas and are exposed to wave effects, and, as a result, need to be protected. The relevance of the issue is due to the fact that an insufficient justification degree of design solutions for engineering protection structures can lead to environmental disasters and large financial losses. Usually, competent and strict regulation of the design process and survey work allows for avoiding large financial losses. Regulatory framework development will improve the reliability of transport facilities located in the wave effect zone. At the same time, technical regulations requirements must be substantiated by scientific research. The article presents some results of scientific research carried out by the author to ensure the regulatory framework development and the safety of transport facilities in wave effect conditions. The following methods of scientific research were used in the work: field observations and surveys of the coastal zone and engineering protection structures of transport facilities from wave effect and physical (hydraulic) modeling. The results of long-term field observations and surveys of the coastal zone and engineering protection structures of the railway roadbed are used: sea wall, protective wave-damping strips, groins, breakwaters, etc. at the Tuapse-Adler sections of the North Caucasian Railway and Korsakov-Nogliki of the Far Eastern Railway. The author presents laboratory studies results of the wave protection structures operation (protective slopes, wave-damping strips with retaining structures, etc.), which were carried out by the physical (hydraulic) modeling method in wave pools and flumes. Provides information about the regulations developed with the author’s participation based on the research. The expected efficiency from the practical application of the developed normative documents is described.

Transient Polycomb activity represses developmental genes in growing oocytes

BackgroundNon-genetic disease inheritance and offspring phenotype are substantially influenced by germline epigenetic programming, including genomic imprinting. Loss of Polycomb Repressive Complex 2 (PRC2) function in oocytes causes non-genetically inherited effects on offspring, including embryonic growth restriction followed by post-natal offspring overgrowth. While PRC2-dependent non-canonical imprinting is likely to contribute, less is known about germline epigenetic programming of non-imprinted genes during oocyte growth. In addition, de novo germline mutations in genes encoding PRC2 lead to overgrowth syndromes in human patients, but the extent to which PRC2 activity is conserved in human oocytes is poorly understood.ResultsIn this study, we identify a discrete period of early oocyte growth during which PRC2 is expressed in mouse growing oocytes. Deletion of Eed during this window led to the de-repression of 343 genes. A high proportion of these were developmental regulators, and the vast majority were not imprinted genes. Many of the de-repressed genes were also marked by the PRC2-dependent epigenetic modification histone 3 lysine 27 trimethylation (H3K27me3) in primary–secondary mouse oocytes, at a time concurrent with PRC2 expression. In addition, we found H3K27me3 was also enriched on many of these genes by the germinal vesicle (GV) stage in human oocytes, strongly indicating that this PRC2 function is conserved in the human germline. However, while the 343 genes were de-repressed in mouse oocytes lacking EED, they were not de-repressed in pre-implantation embryos and lost H3K27me3 during pre-implantation development. This implies that H3K27me3 is a transient feature that represses a wide range of genes in oocytes.ConclusionsTogether, these data indicate that EED has spatially and temporally distinct functions in the female germline to repress a wide range of developmentally important genes and that this activity is conserved in the mouse and human germlines.

Retinal pigmented epithelium development from the perspective of transcription factors and cis‐regulatory elements

AbstractNormal vision depends on the retinal pigmented epithelium (RPE), a metabolic cell layer that is vital to the development and function of the adjacent retinal photoreceptors. The LIM‐homeodomain transcription factor Lhx2 is important key factor for generation of the progenitors of both RPE and retina during early stages of eye development and is also essential for the generation of different stem cells giving rise to multiple types of organs.The purpose of this project is to understand the gene regulatory network (GRN) and the cis‐regulatory sequences bound by Lhx2/LHX2 in mouse and human in the developing and mature retinal pigment epithelium (RPE) of mammals.The methods include functional studies in vivo using Cre/loxP and knockdown approaches in RPE derived from human embryonic stem cells (hES‐RPE). The functional studies are combined with analyses of the global molecular changes, by identifying and characterizing cis‐regulatory regions bound by the complex and the impact of the mutation on gene expression and tissue differentiation.The results reveal essential role for Lhx2 in maintaining RPE fate in the embryonic optic cup and in differentiated hES‐RPE. Lhx2 seems to function as direct regulator of tissue specific transcription factors as well as cytoskeletal and cell adhesion genes.Conclusions: the GRN and the cis regulatory sequences identified provide novel insight on the activity of an important developmental regulator in controlling RPE differentiation, morphology and function in mice and humans.

PALI1 promotes tumor growth through competitive recruitment of PRC2 to G9A-target chromatin for dual epigenetic silencing

PALI1 is a newly identified accessory protein of the Polycomb repressive complex 2 (PRC2) that catalyzes H3K27 methylation. However, the roles of PALI1 in cancer are yet to be defined. Here, we report that PALI1 is upregulated in advanced prostate cancer (PCa) and competes with JARID2 for binding to the PRC2 core subunit SUZ12. PALI1 further interacts with the H3K9 methyltransferase G9A, bridging the formation of a unique G9A-PALI1-PRC2 super-complex that occupies a subset of G9A-target genes to mediate dual H3K9/K27 methylation and gene repression. Many of these genes are developmental regulators required for cell differentiation, and their loss in PCa predicts poor prognosis. Accordingly, PALI1 and G9A drive PCa cell proliferation and invasion invitro and xenograft tumor growth invivo. Collectively, our study shows that PALI1 harnesses two central epigenetic mechanisms to suppress cellular differentiation and promote tumorigenesis, which can be targeted by dual EZH2 and G9A inhibition.

Cyborgs on the horizon. Are we ready? Examining the (a)legality of transhumanist practices within the EU

Abstract Summary Most western contemporary legal systems are grounded in natural law principles established by modern humanism even though various alternatives, post-humanism being among the most influential, start influencing their understanding. In addition, the effect of the rapid pace of technological development on humanity has made the inherent limitations of its rules and other social arrangements manifest, as the use of technology is growingly used for human enhancement. The advocacy seeking to expand the catalogue of human rights and to cover transhumanism has started to bear fruit, but more conceptual developments are needed to lay the foundations for a more systemic regulatory development. This reflection paper focuses on the use of microchip implants, from among the augmentation practices that have recently flown under the radar of legal scientific research. These electronic devices re-shape the experience of being human and their various applications suggest that the penetration levels of capacity enhancing technologies will continue to be on the rise. It will discuss and clarify whether and to which extent transhumanism, personal rights and private autonomy are connected, and the former sufficiently covered by the right to bodily integrity (RBI). The reflection will rely on a comparative and interpretative approach based on the extant literature, national and European Union (EU) regulatory initiatives, and recent doctrinal developments found in case law.

Counter-narrative strategies in deradicalisation: A content analysis of Indonesia’s anti-terrorism laws

This article analysed the Indonesian government’s strategy in eradicating terrorism and radicalism. This study was designed with quantitative methods within the framework of normative legal research using anti-terrorism-related regulations as the sample. Data analysis was carried out with content analysis to identify the conception of terrorism, radicalism and deradicalisation in the legislation. The research found that most of Indonesia’s counter-terrorism regulations associate terrorism with criminal actions. However, regulatory developments also present a decreasing association between terrorism and acts of violence alone as terrorism is growingly being conceptualised by policymakers not only as a virulent action to an increasing extent but also ideologically based on the process of radicalisation. Consequently, various regulations after 2013 accommodate many prevention-based ideas and soft approaches. Newest regulations also accommodate deradicalisation as an important strategy in countering terrorism. This finding practically would imply including counter-narratives through education and deradicalisation strategies. It is also projected through counter-propaganda as a strategic deradicalisation approach. Its incorporation into regulations is needed as digital technology advances, making it easier for young people to be exposed to radical ideas through internet channels.Contribution: This study deepens empirical evidence regarding the need for an alternative soft approach strategy in dealing with religious doctrine-based radicalism. Apart from preventive measures through law enforcement which should be continuously strengthened, the findings in this research encourage preemptive methods in deradicalisation through counter-narrative, counter-propaganda and counter-ideology.

Comparison of the immunomodulatory potential of platinum-based anti-cancer drugs and anthracyclins on human monocyte-derived cells

Macrophages and dendritic cells (DCs) are important contributors to anti-tumor immune responses. However, these highly plastic cells are also the primary targets of tumor manipulation, which may result in the development of tumor-promoting subtypes. The effect of chemotherapeutic agents on tumor cells is an area of intense study, but little is known about their effects on innate immune cells.We investigated the effects of four chemotherapeutic drugs (two platinum-based agents; oxaliplatin and cisplatin, and two anthracyclines; doxorubicin and epirubicin) on the differentiation, function, and viability of macrophages and DCs. Macrophages and DCs were differentiated from monocytes in the presence of these chemotherapeutic drugs and we compared their cell surface receptor expression, cytokine production, and chemotactic- and T-cell-polarizing ability.We have shown that differentiation in the presence of anthracyclines dose-dependently increases CTLA-4 expression in DCs. Antineoplastic agent-driven differentiation strongly modified the CCL2- or CCL5-induced chemotactic activity of both macrophages and DCs. DCs differentiated in the presence of high-dose cisplatin and a low dose of epirubicin promoted regulatory T-cell development, whereas oxaliplatin at specific doses induced both DCs and macrophages to enhance cytotoxic T-cell responses. Furthermore, we found that inflammatory macrophages are more sensitive to doxorubicin-induced cell death than their counterparts.In summary, our results confirm that chemotherapeutic agents acting on a similar basis may have different effects on the anti-tumor immune response. Treatment with optimal dose, combinations, and timing of chemotherapy may determine tumor immunity and the metastatic potential of tumors.

Inducible degradation of the Drosophila Mediator subunit Med19 reveals its role in regulating developmental but not constitutively-expressed genes.

The multi-subunit Mediator complex plays a critical role in gene expression by bridging enhancer-bound transcription factors and the RNA polymerase II machinery. Although experimental case studies suggest differential roles of Mediator subunits, a comprehensive view of the specific set of genes regulated by individual subunits in a developing tissue is still missing. Here we address this fundamental question by focusing on the Med19 subunit and using the Drosophila wing imaginal disc as a developmental model. By coupling auxin-inducible degradation of endogenous Med19 in vivo with RNA-seq, we got access to the early consequences of Med19 elimination on gene expression. Differential gene expression analysis reveals that Med19 is not globally required for mRNA transcription but specifically regulates positively or negatively less than a quarter of the expressed genes. By crossing our transcriptomic data with those of Drosophila gene expression profile database, we found that Med19-dependent genes are highly enriched with spatially-regulated genes while the expression of most constitutively expressed genes is not affected upon Med19 loss. Whereas globally downregulation does not exceed upregulation, we identified a functional class of genes encoding spatially-regulated transcription factors, and more generally developmental regulators, responding unidirectionally to Med19 loss with an expression collapse. Moreover, we show in vivo that the Notch-responsive wingless and the E(spl)-C genes require Med19 for their expression. Combined with experimental evidences suggesting that Med19 could function as a direct transcriptional effector of Notch signaling, our data support a model in which Med19 plays a critical role in the transcriptional activation of developmental genes in response to cell signaling pathways.

African Swine Fever Modified Live Vaccine Candidates: Transitioning from Discovery to Product Development through Harmonized Standards and Guidelines.

The recent centennial anniversary of R.E. Montgomery's seminal published description of "a form of swine fever" disease transmitted from wild African pigs to European domestic pigs is a call to action to accelerate African Swine Fever (ASF) vaccine research and development. ASF modified live virus (MLV) first-generation gene deleted vaccine candidates currently offer the most promise to meet international and national guidelines and regulatory requirements for veterinary product licensure and market authorization. A major, rate-limiting impediment to the acceleration of current as well as future vaccine candidates into regulatory development is the absence of internationally harmonized standards for assessing vaccine purity, potency, safety, and efficacy. This review summarizes the asymmetrical landscape of peer-reviewed published literature on ASF MLV vaccine approaches and lead candidates, primarily studied to date in the research laboratory in proof-of-concept or early feasibility clinical safety and efficacy studies. Initial recommendations are offered toward eventual consensus of international harmonized guidelines and standards for ASF MLV vaccine purity, potency, safety, and efficacy. To help ensure the successful regulatory development and approval of ASF MLV first generation vaccines by national regulatory associated government agencies, the World Organisation for Animal Health (WOAH) establishment and publication of harmonized international guidelines is paramount.

Heavy metals in agricultural soil in China: A systematic review and meta-analysis

Research about farmland pollution by heavy metals/metalloids in China has drawn growing attention. However, there was rare information on spatiotemporal evolution and pollution levels of heavy metals in the major grain-producing areas. We extracted and examined data from 276 publications between 2010 and 2021 covering five major grain-producing regions in China from 2010 to 2021. Spatiotemporal evolution characteristics of main heavy metals/metalloids was obtained by meta-analysis. In addition, subgroup analyses were carried out to study preliminary correlations related to accumulation of the pollutants. Cadmium (Cd) was found to be the most prevailing pollutant in the regions in terms of both spatial distribution and temporal accumulation. The Huang-Huai-Hai Plain was the most severely polluted. Accumulation of Cd, mercury (Hg) and copper (Cu) increased from 2010 to 2015 when compared with the 1990 background data. Further, the levels of five key heavy metals (Cd, Cu, Hg, lead [Pb] and zinc [Zn]) showed increasing trends from 2016 to 2021 in all five regions. Soil pH and mean annual precipitation had variable influences on heavy metal accumulation. Alkaline soil and areas with less rainfall faced higher pollution levels. Farmlands cropped with mixed species showed smaller effect sizes of heavy metals than those with single upland crop, suggesting that mixed farmland use patterns could alleviate the levels of heavy metals in soil. Of various soil remediation efforts, farmland projects only held a small market share. The findings are important to support the research of risk assessment, regulatory development, pollution prevention, fund allocation and remediation actions.

Time-course transcriptome analysis reveals regulation of Arabidopsis seed dormancy by the transcription factors WOX11/12.

The induction of seed dormancy and its release involve a finely regulated genetic program controlled by various environmental and developmental cues that are critical for plant survival and population expansion. Light plays a key role in seed dormancy and germination, but the molecular mechanisms underlying the control of dormancy are unclear. In the present study, high-resolution temporal RNA-seq in Arabidopsis identified WOX11 as encoding a hub transcription factor during the seed dormancy induction and release stages. This gene might have evolved from gymnosperms and expanded in angiosperms with highly conserved expression patterns in seeds. WOX11 and its homolog WOX12 were highly expressed from 2 d after pollination, and mRNA abundance was greatly increased during the seed dormancy induction and release stages. Further, we found that WOX11 plays a role in the regulation of seed dormancy downstream of phytochrome B (PHYB)-mediated red-light signaling during the induction stage, indicating that WOX11/12 are newly identified components of red-light signaling transduction. Taken together, our results suggest that WOX11/12-mediated PHYB signaling regulates seed dormancy in Arabidopsis, and provide insights into the developmental regulation and evolutionary adaptation of plants to changes in the light environment.

MINI BODY1, encoding a MATE/DTX family transporter, affects plant architecture in mungbean (Vigna radiata L.).

It has been shown that multidrug and toxic compound extrusion/detoxification (MATE/DTX) family transporters are involved in the regulation of plant development and stress response. Here, we characterized the mini body1 (mib1) mutants in mungbean, which gave rise to increased branches, pentafoliate compound leaves, and shortened pods. Map-based cloning revealed that MIB1 encoded a MATE/DTX family protein in mungbean. qRT-PCR analysis showed that MIB1 was expressed in all tissues of mungbean, with the highest expression level in the young inflorescence. Complementation assays in Escherichia coli revealed that MIB1 potentially acted as a MATE/DTX transporter in mungbean. It was found that overexpression of the MIB1 gene partially rescued the shortened pod phenotype of the Arabidopsis dtx54 mutant. Transcriptomic analysis of the shoot buds and young pods revealed that the expression levels of several genes involved in the phytohormone pathway and developmental regulators were altered in the mib1 mutants. Our results suggested that MIB1 plays a key role in the control of plant architecture establishment in mungbean.

An ancestral Wnt-Brachyury feedback loop in axial patterning and recruitment of mesoderm-determining target genes.

Transcription factors are crucial drivers of cellular differentiation during animal development and often share ancient evolutionary origins. The T-box transcription factor Brachyury plays a pivotal role as an early mesoderm determinant and neural repressor in vertebrates; yet, the ancestral function and key evolutionary transitions of the role of this transcription factor remain obscure. Here, we present a genome-wide target-gene screen using chromatin immunoprecipitation sequencing in the sea anemone Nematostella vectensis, an early branching non-bilaterian, and the sea urchin Strongylocentrotus purpuratus, a representative of the sister lineage of chordates. Our analysis reveals an ancestral gene regulatory feedback loop connecting Brachyury, FoxA and canonical Wnt signalling involved in axial patterning that predates the cnidarian-bilaterian split about 700 million years ago. Surprisingly, we also found that part of the gene regulatory network controlling the fate of neuromesodermal progenitors in vertebrates was already present in the common ancestor of cnidarians and bilaterians. However, while several endodermal and neuronal Brachyury target genes are ancestrally shared, hardly any of the key mesodermal downstream targets in vertebrates are found in the sea anemone or the sea urchin. Our study suggests that a limited number of target genes involved in mesoderm formation were newly acquired in the vertebrate lineage, leading to a dramatic shift in the function of this ancestral developmental regulator.

Genome-wide identification and expression analysis of the bHLH gene family in passion fruit (Passiflora edulis) and its response to abiotic stress

Passion fruit is a tropical fruit crop with significant agricultural, economic and ornamental values. The growth and development of passion fruit are greatly affected by climatic conditions. In plants, the basic helix-loop-helix (bHLH) gene family plays essential roles in the floral organ and fruit development, as well as stress response. However, the characteristics and functions of the bHLH genes of passion fruit remain unclear. Here, 138 passion fruit bHLH members were identified and classified into 20 subfamilies. The structural analysis illustrated that PebHLH proteins of the specific subfamily are relatively conserved. Collinearity analysis indicated that the expansion of the PebHLH gene family mainly took place by segmental duplication, and the structural diversity of duplicated genes might contribute to their functional diversity. PebHLHs, which potentially regulate different floral organ and fruit development, were further screened out, and many of these genes were differentially expressed under various stress treatments. The co-presence of different cis-regulatory elements involved in developmental regulation, hormone and stress responses in the promoter regions of PebHLHs might be closely related to their diverse regulatory roles. Overall, this study will be helpful for further functional investigation of PebHLHs and provides clues for improvement of the passion fruit breeding.

Prolonged Combinatorial Pharmacological Therapy Targeting the Epigenome Increases Fetal Hemoglobin to Clinically Relevant Levels in Normal, Nonanemic Baboons

Elevated levels of Fetal Hemoglobin (HbF; α2γ2) reduce the symptoms associated with Sickle Cell Disease (SCD) and increase the lifespan of patients. An effective pharmacological therapy that increases HbF would advance the treatment of SCD. HbF levels are developmentally regulated by transcriptional repression of the γ-globin gene in adult erythroid cells. This is achieved by a co-repressor complex containing multiple enzymes that catalyze repressive epigenetic modifications of chromatin targeted to the γ-globin promoter by site-specific DNA binding proteins. Pharmacological inhibitors of repressive epigenetic enzymes within the complex including DNMT1, LSD1 (KDM1A), G9A, and HDACs increase HbF in cell line and animal models and SCD patients. Many of these drugs have been studied in Phase 1 trials, but only the DNMT inhibitor decitabine (DAC) has advanced to Phase 3 trials. The successful development of a pharmacological therapy to increase HbF for SCD has thus far been hindered by dose-limiting side effects including neutropenia, thrombocytopenia, and/or thrombophilia. The goal of this current work is to develop a pharmacological therapy employing a combination of drugs that target different repressive epigenetic enzymes within the co-repressor complex based on the hypothesis that administration of these drugs in combination will reduce the dose and/or time of exposure to any single agent to minimize adverse effects while still stimulating clinically meaningful HbF elevations. To test this hypothesis, baboons, long considered the best animal model to test the effect of HbF-inducing agents due to conservation of the structure and developmental regulation of the β-globin gene locus between baboons and humans, were treated with a combination of two drugs, DAC and RN-1, that inhibit DNMT1 and LSD1 respectively. Analysis of seven baboons used in our studies showed that they comprised two phenotypic groups differentiated by baseline pre-treatment HbF expression (Figure 1). Two baboons of each phenotypic group were chosen to study the effect of DAC and RN-1, alone and in combination, on HbF. Either RN-1 (0.25mg/kg/d) or DAC (0.5mg/kg/d), were administered subcutaneously individually or in combination to normal, non-anemic animals for 2 days. The effect on γ-globin expression was measured by flow cytometry analysis of F-retics and RT-PCR of γ-globin mRNA in peripheral blood at least 3X per week post-drug treatments. Each drug induced a significant increase in F-retics and peripheral blood γ-globin mRNA in both phenotypic groups that peaked on d8 (Figure 1) while differences in F-retics and γ-globin mRNA between the two groups were maintained. Combined administration (RN-1 (0.25mg/kg/d; DAC (0.5mg/kg/d); 2d) increased levels of F-retics and γ-globin mRNA to greater than additive levels (Figure 1) while the difference in γ-globin mRNA (p<0.02), but not F-retics, between the two groups was still observed. To assess the effect of sustained administration of the two drug combination on HbF expression and evaluate possible hematological toxicity, two normal baboons, one of the low HbF group (PA 9254) and one of the high HbF group (PA 9194), were treated weekly with 12 total courses of the DAC-RN-1 combination (DAC, 0.5mg/kg/d; RN-1, 0.25mg/kg/d; 2d/wk). F cells increased approximately 6 fold to 60.5% in the high HbF animal and >10 fold to 42% in the low HbF baboon (Table 1). HPLC analysis of globin chain expression showed that HbF (γ/γ+β) increased tenfold in each animal (Table 1). The calculated % HbF/ F cell values were 33% for PA 9194 (High HbF group) and 23.5% for PA 9254 (Low HbF group). No instances of moderate or severe neutropenia, thrombocytopenia, or thrombophilia were observed during the treatment period (Table 1). Decreased Hct, Hb, and RBCs were apparent in the high HbF group baboon (PA 9194) but not the low HbF group baboon (PA 9254). In conclusion, combinatorial administration of DAC and RN-1 increased HbF and F cell numbers in a greater than additive manner. Prolonged treatment of two normal, nonanemic baboons increased F cells and HbF to levels predicted to be clinically significant in the absence of neutropenia, thrombocytopenia and/or thrombophilia throughout the treatment period although a reduction in Hct, RBCs, and Hb was observed in one animal. These results strongly suggest additional drug combinations, dosing, and schedules to increase HbF for the treatment of SCD should be pursued. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Human iPSC-Derived Cortical Neurons Display Homeostatic Plasticity.

Maintaining the excitability of neurons and circuits is fundamental for healthy brain functions. The global compensatory increase in excitatory synaptic strength, in response to decreased activity, is one of the main homeostatic mechanisms responsible for such regulation. This type of plasticity has been extensively characterized in rodents in vivo and in vitro, but few data exist on human neurons maturation. We have generated an in vitro cortical model system, based on differentiated human-induced pluripotent stem cells, chronically treated with tetrodotoxin, to investigate homeostatic plasticity at different developmental stages. Our findings highlight the presence of homeostatic plasticity in human cortical networks and show that the changes in synaptic strength are due to both pre- and post-synaptic mechanisms. Pre-synaptic plasticity involves the potentiation of neurotransmitter release machinery, associated to an increase in synaptic vesicle proteins expression. At the post-synaptic level, we report an increase in the expression of post-synaptic density proteins, involved in glutamatergic receptor anchoring. These results extend our understanding of neuronal homeostasis and reveal the developmental regulation of its expression in human cortical networks. Since induced pluripotent stem cell-derived neurons can be obtained from patients with neurodevelopmental and neurodegenerative diseases, our platform offers a versatile model for assessing human neural plasticity under physiological and pathological conditions.

Overexpression of a Senescence-Related Gene CpSRG1 from Wintersweet (Chimonanthus praecox) Promoted Growth and Flowering, and Delayed Senescence in Transgenic Arabidopsis.

Plant senescence is a complex process that is controlled by developmental regulation and genetic programs. A senescence-related gene CpSRG1, which belongs to the 2OG-Fe(II) dioxygenase superfamily, was characterized from wintersweet, and the phylogenetic relationship of CpSRG1 with homologs from other species was investigated. The expression analysis by qRT-PCR (quantitative real-time PCR) indicated that CpSRG1 is abundant in flower organs, especially in petals and stamens, and the highest expression of CpSRG1 was detected in stage 6 (withering period). The expression patterns of the CpSRG1 gene were further confirmed in CpSRG1pro::GUS (β-glucuronidase) plants, and the activity of the CpSRG1 promoter was enhanced by exogenous Eth (ethylene), SA (salicylic acid), and GA3 (gibberellin). Heterologous overexpression of CpSRG1 in Arabidopsis promoted growth and flowering, and delayed senescence. Moreover, the survival rates were significantly higher and the root lengths were significantly longer in the transgenic lines than in the wild-type plants, both under low nitrogen stress and GA3 treatment. This indicated that the CpSRG1 gene may promote the synthesis of assimilates in plants through the GA pathway, thereby improving growth and flowering, and delaying senescence in transgenic Arabidopsis. Our study has laid a satisfactory foundation for further analysis of senescence-related genes in wintersweet and wood plants. It also enriched our knowledge of the 2OG-Fe(II) dioxygenase superfamily, which plays a variety of important roles in plants.

Glandular trichome specificity of menthol biosynthesis pathway gene promoters from Mentha × piperita.

Several cis-elements including Myb-binding motifs together confer glandular trichome specificity as revealed from heterologous expression and analysis of menthol biosynthesis pathway gene promoters. Glandular Trichomes (GTs) are result of division of epidermal cells that produce diverse metabolites. Species of mint family are important for their essential oil containing many high-value terpenoids, biosynthesized and stored in these GTs. Hence, GTs constitute attractive targets for metabolic engineering and GT-specific promoters are important. In this investigation, the upstream regions of the Mentha × piperita menthol biosynthetic pathway genes (-)-limonene synthase, (-)-P450 limonene-3- hydroxylase, (-)-trans-isopiperitenol dehydrogenase, (-)-Isopiperitenone reductase, ( +)-Pulegone reductase, (-)-Menthone reductase/ (-)-Menthol dehydrogenase and a branched pathway gene ( +)-menthofuran synthase were isolated and characterized. These fragments, fused to β-glucuronidase (GUS) reporter gene of pBI101 binary vector, are able to drive high level gene expression in transgenic tobacco trichomes with strong signals in GTs, except for (-)-Isopiperitenone reductase. The GT-enriched tissue from transformed plants were analysed for GUS enzyme activity and RNA expression which correlates the GUS staining. To characterize the cis-elements responsible for GT-specific expression, a series of 5' deletion constructs for MpPLS and MpPMFS were cloned and analysed in stable transgenic tobacco lines. The specificity of trichome expression was located to - 797 to- 598bp sequence for (-)-limonene synthase and- 629 to - 530bp for ( +)-menthofuran synthase promoters containing specific Myb-binding motifs in addition to other unique motifs described for developmental regulation without any defined pattern. All other pathway promoters also recruits specific but different Myb factors as indicated by this analysis.

Developmental toxicity of remdesivir, an anti-COVID-19 drug, is implicated by in vitro assays using morphogenetic embryoid bodies of mouse and human pluripotent stem cells.

Remdesivir is an antiviral drug approved for the treatment of COVID-19, whose developmental toxicity remains unclear. More information about the safety of remdesivir is urgently needed for people of childbearing potential, who are affected by the ongoing pandemic. Morphogenetic embryoid bodies (MEBs) are three-dimensional (3D) aggregates of pluripotent stem cells that recapitulate embryonic body patterning in vitro, and have been used as effective embryo models to detect the developmental toxicity of chemical exposures specifically and sensitively. MEBs were generated from mouse P19C5 and human H9 pluripotent stem cells, and used to examine the effects of remdesivir. The morphological effects were assessed by analyzing the morphometric parameters of MEBs after exposure to varying concentrations of remdesivir. The molecular impact of remdesivir was evaluated by measuring the transcript levels of developmental regulator genes. The mouse MEB morphogenesis was impaired by remdesivir at 1-8μM. Remdesivir affected MEBs in a manner dependent on metabolic conversion, and its potency was higher than GS-441524 and GS-621763, presumptive anti-COVID-19 drugs that act similarly to remdesivir. The expressions of developmental regulator genes, particularly those involved in axial and somite patterning, were dysregulated by remdesivir. The early stage of MEB development was more vulnerable to remdesivir exposure than the later stage. The morphogenesis and gene expression profiles of human MEBs were also impaired by remdesivir at 1-8μM. Remdesivir impaired mouse and human MEBs at concentrations that are comparable to the therapeutic plasma levels in humans, urging further investigation into the potential impact of remdesivir on developing embryos.