19 research outputs found
Construction of plant gene expression vectors carrying ath-Mir393a gene and its target gene AFB3
MicroRNAs (miRNA) are a class of non-coding small RNAs that regulate gene expression. Plant miRNAs are involved in a broad range of biological processes including growth, developmental patterning and abiotic stress responses. In our previous miRNA profiling results in response to glyphosate, ath-Mir393a was found to be up-regulated at the 5 % glyphosate application whereas down-regulated at the 20 % foliar glyphosate application when compared to control samples of Festuca arundinacea. Ath-Mir393a is a conserved miRNA species that targets F-box proteins TIR1 and AFB1/2/3 transcripts. F-box motif mediates protein-protein interactions and mostly found in proteins as components of SCF ubiquitin-ligase complexes. Hence they have very important roles in the maintenance of protein stabilities inside the cell. TIR1 and AFBs have shown that they are associated with auxin signaling pathways as auxin receptors. In order to improve the management of weed invasion on crop lands, the idea of developing genetically engineered cultivars which are glyphosate-resistant has become a necessity. Therefore in this study two plant gene expression vectors carrying Arabidopsis thaliana ath-Mir393a gene and AFB3 gene were constructed by using Gateway technology. Ath-Mir393a and AFB3 genes were first captured in 'entry vectors' and then recombined into pEARLEY Gate100 Gateway compatible 'destination vectors'. These vectors are later used for Agrobacterium-mediated transformation of Arabidopsis thaliana. These vectors constructed in this study will be a good starting point for exploring and elucidating the miRNAs associated with regulation of plant responses to glyphosate
Cognitive functions in neurofibromatosis type 1 patients and unaffected siblings
Attention, learning, and perceptual problems have been reported at various degrees and rates in neurofibromatosis type 1 (NF1). We aimed to define the cognitive profiles frequently associated with NF1. Children and adolescents with NF1 (n=58) were tested using Wechsler Intelligence Scales for Children-Revised (WISC-R), Judgment of Line Orientation, and Bender Visual-Motor Gestalt tests. Comparison groups were unaffected siblings of NF1 patients (n=20), children with attention deficit and hyperactivity disorder (ADHD, n=40), and normal children (n=40). No difference was found between familial or sporadic NF1 cases. Seventeen/58 (29%) of NF1 cases had a full scale IQ 80 (n=27) scored lower in WISC-R subtests measuring visual perception when compared to a healthy control group of similar intelligence, and lower in arithmetic but better in Bender-Gestalt and Judgment of Line Orientation tests when compared to an ADHD group of similar intelligence. These results indicate a high prevalence of mental retardation in a clinical NF1 series. NF1 patients who have normal intelligence may have impaired visual perception, but their visual perceptual problems are less than in ADHD. The tendency of unaffected siblings of NF1 patients to have mildly but consistently low test scores compared to healthy controls needs to be studied further for underlying genetic or environmental factors
Cognitive functions in neurofibromatosis type 1 patients and unaffected siblings
Attention, learning, and perceptual problems have been reported at various
degrees and rates in neurofibromatosis type 1 (NF1). We aimed to define the
cognitive profiles frequently associated with NF1. Children and adolescents
with NF1 (n=58) were tested using Wechsler Intelligence Scales for Children-
Revised (WISC-R), Judgment of Line Orientation, and Bender Visual-Motor
Gestalt tests. Comparison groups were unaffected siblings of NF1 patients
(n=20), children with attention deficit and hyperactivity disorder (ADHD,
n=40), and normal children (n=40). No difference was found between
familial or sporadic NF1 cases. Seventeen/58 (29%) of NF1 cases had a full
scale IQ 80 (n=27)
scored lower in WISC-R subtests measuring visual perception when compared
to a healthy control group of similar intelligence, and lower in arithmetic
but better in Bender-Gestalt and Judgment of Line Orientation tests when
compared to an ADHD group of similar intelligence. These results indicate a
high prevalence of mental retardation in a clinical NF1 series. NF1 patients
who have normal intelligence may have impaired visual perception, but
their visual perceptual problems are less than in ADHD. The tendency of
unaffected siblings of NF1 patients to have mildly but consistently low test
scores compared to healthy controls needs to be studied further for underlying
genetic or environmental factors
Variable expression and silencing of CRISPR-Cas9 targeted transgenes identifies the AAVS1 locus as not an entirely safe harbour
Background: Diseases such as hypertrophic cardiomyopathy (HCM) can lead to severe outcomes including sudden death. The generation of human induced pluripotent stem cell (hiPSC) reporter lines can be useful for disease modelling and drug screening by providing physiologically relevant in vitro models of disease. The AAVS1 locus is cited as a safe harbour that is permissive for stable transgene expression, and hence is favoured for creating gene targeted reporter lines. Methods: We generated hiPSC reporters using a plasmid-based CRISPR/Cas9 nickase strategy. The first intron of PPP1R12C, the AAVS1 locus, was targeted with constructs expressing a genetically encoded calcium indicator (R-GECO1.0) or HOXA9-T2A-mScarlet reporter under the control of a pCAG or inducible pTRE promoter, respectively. Transgene expression was compared between clones before, during and/or after directed differentiation to mesodermal lineages. Results: Successful targeting to AAVS1 was confirmed by PCR and sequencing. Of 24 hiPSC clones targeted with pCAG-R-GECO1.0, only 20 expressed the transgene and in these, the percentage of positive cells ranged from 0% to 99.5%. Differentiation of a subset of clones produced cardiomyocytes, wherein the percentage of cells positive for R-GECO1.0 ranged from 2.1% to 93.1%. In the highest expressing R-GECO1.0 clones, transgene silencing occurred during cardiomyocyte differentiation causing a decrease in expression from 98.93% to 1.3%. In HOXA9-T2A-mScarlet hiPSC reporter lines directed towards mesoderm lineages, doxycycline induced a peak in transgene expression after two days but this reduced by up to ten-thousand-fold over the next 8-10 days. Nevertheless, for R-GECO1.0 lines differentiated into cardiomyocytes, transgene expression was rescued by continuous puromycin drug selection, which allowed the Ca 2+ responses associated with HCM to be investigated in vitro using single cell analysis. Conclusions: Targeted knock-ins to AAVS1 can be used to create reporter lines but variability between clones and transgene silencing requires careful attention by researchers seeking robust reporter gene expression
Isogenic models of hypertrophic cardiomyopathy unveil differential phenotypes and mechanism-driven therapeutics
Background: Hypertrophic cardiomyopathy (HCM) is a prevalent and complex cardiovascular condition. Despite being strongly associated with genetic alterations, wide variation of disease penetrance, expressivity and hallmarks of progression complicate treatment. We aimed to characterize different human isogenic cellular models of HCM bearing patient-relevant mutations to clarify genetic causation and disease mechanisms, hence facilitating the development of effective therapeutics. Methods: We directly compared the p.β-MHC-R453C and p.ACTC1-E99K HCM-associated mutations in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and their healthy isogenic counterparts, generated using CRISPR/Cas9 genome editing technology. By harnessing several state-of-the-art HCM phenotyping techniques, these mutations were investigated to identify similarities and differences in disease progression and hypertrophic signaling pathways, towards establishing potential targets for pharmacological treatment. CRISPR/Cas9 knock-in of the genetically-encoded calcium indicator R-GECO1.0 to the AAVS1 locus into these disease models resulted in calcium reporter lines. Results: Confocal line scan analysis identified calcium transient arrhythmias and intracellular calcium overload in both models. The use of optogenetics and 2D/3D contractility assays revealed opposing phenotypes in the two mutations. Gene expression analysis highlighted upregulation of CALM1, CASQ2 and CAMK2D, and downregulation of IRF8 in p.β-MHC-R453C mutants, whereas the opposite changes were detected in p.ACTC1-E99K mutants. Contrasting profiles of nuclear translocation of NFATc1 and MEF2 between the two HCM models suggest differential hypertrophic signaling pathway activation. Calcium transient abnormalities were rescued with combination of dantrolene and ranolazine, whilst mavacamten reduced the hyper-contractile phenotype of p.ACTC1-E99K hiPSC-CMs. Conclusions: Our data show that hypercontractility and molecular signaling within HCM are not uniform between different gene mutations, suggesting that a ‘one-size fits all’ treatment underestimates the complexity of the disease. Understanding where the similarities (arrhythmogenesis, bioenergetics) and differences (contractility, molecular profile) lie will allow development of therapeutics that are directed towards common mechanisms or tailored to each disease variant, hence providing effective patient-specific therapy
Variable expression and silencing of CRISPR-Cas9 targeted transgenes identifies the AAVS1 locus as not an entirely safe harbour
Background: Diseases such as hypertrophic cardiomyopathy (HCM) can lead to severe outcomes including sudden death. The generation of human induced pluripotent stem cell (hiPSC) reporter lines can be useful for disease modelling and drug screening by providing physiologically relevant in vitro models of disease. The AAVS1 locus is cited as a safe harbour that is permissive for stable transgene expression, and hence is favoured for creating gene targeted reporter lines.Methods: We generated hiPSC reporters using a plasmid-based CRISPR/Cas9 nickase strategy. The first intron of PPP1R12C, the AAVS1 locus, was targeted with constructs expressing a genetically encoded calcium indicator (R-GECO1.0) or HOXA9-T2A-mScarlet reporter under the control of a pCAG or inducible pTRE promoter, respectively. Transgene expression was compared between clones before, during and/or after directed differentiation to mesodermal lineages.Results: Successful targeting to AAVS1 was confirmed by PCR and sequencing. Of 24 hiPSC clones targeted with pCAG-R-GECO1.0, only 20 expressed the transgene and in these, the percentage of positive cells ranged from 0% to 99.5%. Differentiation of a subset of clones produced cardiomyocytes, wherein the percentage of cells positive for R-GECO1.0 ranged from 2.1% to 93.1%. In the highest expressing R-GECO1.0 clones, transgene silencing occurred during cardiomyocyte differentiation causing a decrease in expression from 98.93% to 1.3%. In HOXA9-T2A-mScarlet hiPSC reporter lines directed towards mesoderm lineages, doxycycline induced a peak in transgene expression after two days but this reduced by up to ten-thousand-fold over the next 8-10 days. Nevertheless, for R-GECO1.0 lines differentiated into cardiomyocytes, transgene expression was rescued by continuous puromycin drug selection, which allowed the Ca2+ responses associated with HCM to be investigated in vitro using single cell analysis.Conclusions: Targeted knock-ins to AAVS1 can be used to create reporter lines but variability between clones and transgene silencing requires careful attention by researchers seeking robust reporter gene expression
Genome-wide profiling and analysis of Festuca arundinacea miRNAs and transcriptomes in response to foliar glyphosate application
Glyphosate is a broad spectrum herbicide which has been widely used for non-selective weed control in turfgrass management. Festuca arundinacea cv. Falcon was shown to be one of the tolerant turfgrass species in response to varying levels of glyphosate [5% (1.58 mM), 20% (6.32 mM)] recommended for weed control. However, there is a lack of knowledge on the mRNA expression patterns and miRNA, critical regulators of gene expression, in response to varying levels of glyphosate treatments. Here, we investigate the transcriptome and miRNA-guided post-transcriptional networks using plant miRNA microarray and Affymetrix GeneChip(A (R)) Wheat Genome Array platforms. Transcriptome analysis revealed 93 up-regulated and 78 down-regulated genes, whereas a smaller number showed inverse differential expressions. miRNA chip analysis indicated a number of (34 out of the 853) plant miRNAs were differentially regulated in response to glyphosate treatments. Target transcripts of differentially regulated miRNAs were predicted and nine of them were quantified by quantitative real-time PCR (qRT-PCR). Target transcripts of miRNAs validate the expression level change of miRNAs detected by miRNA microarray analysis. Down-regulation of miRNAs upon 5 and 20% glyphosate applications led to the up-regulation of their target observed by qRT-PCR or vice versa. Quantification of F. arundinacea miRNA, homologous of osa-miR1436, revealed the agreement between the Affymetrix and miRNA microarray analyses. In addition to miRNA microarray experiment, 25 conserved F. arundinacea miRNAs were identified through homology-based approach and their secondary structures were predicted. The results presented serve as analyses of genome-wide expression profiling of miRNAs and target mRNAs in response to foliar glyphosate treatment in grass species
Pertussis antibody levels in infants and their mothers receiving combined tetanus-diphtheria toxoid and acellular pertussis vaccine during pregnancy in Turkey
Objective: Pertussis is an important cause of morbidity and mortality in infants under two months of age and these high risk babies are dependent on maternally derived antibodies until completion of their first immunization series. This study aimed to evaluate the vaccine response of late preterm and term new-borns as well as their mothers who underwent combined tetanus-diphtheria toxoid and acellular pertus-sis (Tdap) vaccination during pregnancy
The effect of vascular endothelial growth factor overexpression in experimental necrotizing enterocolitis
Necrotizing enterocolitis (NEC) is a serious condition, predominantly observed in premature infants. We used an experimental NEC model to investigate the effects of vascular endothelial growth factor (VEGF) cloned into a plasmid