Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 45
Filter
1.
Stem Cell Reports ; 18(11): 2123-2137, 2023 11 14.
Article in English | MEDLINE | ID: mdl-37802072

ABSTRACT

Primary carnitine deficiency (PCD) is an autosomal recessive monogenic disorder caused by mutations in SLC22A5. This gene encodes for OCTN2, which transports the essential metabolite carnitine into the cell. PCD patients suffer from muscular weakness and dilated cardiomyopathy. Two OCTN2-defective human induced pluripotent stem cell lines were generated, carrying a full OCTN2 knockout and a homozygous OCTN2 (N32S) loss-of-function mutation. OCTN2-defective genotypes showed lower force development and resting length in engineered heart tissue format compared with isogenic control. Force was sensitive to fatty acid-based media and associated with lipid accumulation, mitochondrial alteration, higher glucose uptake, and metabolic remodeling, replicating findings in animal models. The concordant results of OCTN2 (N32S) and -knockout emphasizes the relevance of OCTN2 for these findings. Importantly, genome-wide analysis and pharmacological inhibitor experiments identified ferroptosis, an iron- and lipid-dependent cell death pathway associated with fibroblast activation as a novel PCD cardiomyopathy disease mechanism.


Subject(s)
Cardiomyopathies , Ferroptosis , Induced Pluripotent Stem Cells , Animals , Humans , Organic Cation Transport Proteins/genetics , Solute Carrier Family 22 Member 5/genetics , Cardiomyopathies/genetics , Lipids
2.
Cell Mol Neurobiol ; 43(7): 3511-3526, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37219662

ABSTRACT

The BAF (BRG1/BRM-associated factor) chromatin remodelling complex is essential for the regulation of DNA accessibility and gene expression during neuronal differentiation. Mutations of its core subunit SMARCB1 result in a broad spectrum of pathologies, including aggressive rhabdoid tumours or neurodevelopmental disorders. Other mouse models have addressed the influence of a homo- or heterozygous loss of Smarcb1, yet the impact of specific non-truncating mutations remains poorly understood. Here, we have established a new mouse model for the carboxy-terminal Smarcb1 c.1148del point mutation, which leads to the synthesis of elongated SMARCB1 proteins. We have investigated its impact on brain development in mice using magnetic resonance imaging, histology, and single-cell RNA sequencing. During adolescence, Smarcb11148del/1148del mice demonstrated rather slow weight gain and frequently developed hydrocephalus including enlarged lateral ventricles. In embryonic and neonatal stages, mutant brains did not differ anatomically and histologically from wild-type controls. Single-cell RNA sequencing of brains from newborn mutant mice revealed that a complete brain including all cell types of a physiologic mouse brain is formed despite the SMARCB1 mutation. However, neuronal signalling appeared disturbed in newborn mice, since genes of the AP-1 transcription factor family and neurite outgrowth-related transcripts were downregulated. These findings support the important role of SMARCB1 in neurodevelopment and extend the knowledge of different Smarcb1 mutations and their associated phenotypes.


Subject(s)
Hydrocephalus , Transcription Factor AP-1 , Animals , Mice , Hydrocephalus/genetics , Mutation/genetics , Point Mutation/genetics , Signal Transduction , Transcription Factor AP-1/genetics
3.
J Biol Chem ; 298(9): 102362, 2022 09.
Article in English | MEDLINE | ID: mdl-35963431

ABSTRACT

The activity of protein phosphatase 2A (PP2A) is determined by the expression and localization of the regulatory B-subunits. PP2A-B56α is the dominant isoform of the B'-family in the heart. Its role in regulating the cardiac response to ß-adrenergic stimulation is not yet fully understood. We therefore generated mice deficient in B56α to test the functional cardiac effects in response to catecholamine administration versus corresponding WT mice. We found the decrease in basal PP2A activity in hearts of KO mice was accompanied by a counter-regulatory increase in the expression of B' subunits (ß and γ) and higher phosphorylation of sarcoplasmic reticulum Ca2+ regulatory and myofilament proteins. The higher phosphorylation levels were associated with enhanced intraventricular pressure and relaxation in catheterized KO mice. In contrast, at the cellular level, we detected depressed Ca2+ transient and sarcomere shortening parameters in KO mice at basal conditions. Consistently, the peak amplitude of the L-type Ca2+ current was reduced and the inactivation kinetics of ICaL were prolonged in KO cardiomyocytes. However, we show ß-adrenergic stimulation resulted in a comparable peak amplitude of Ca2+ transients and myocellular contraction between KO and WT cardiomyocytes. Therefore, we propose higher isoprenaline-induced Ca2+ spark frequencies might facilitate the normalized Ca2+ signaling in KO cardiomyocytes. In addition, the application of isoprenaline was associated with unchanged L-type Ca2+ current parameters between both groups. Our data suggest an important influence of PP2A-B56α on the regulation of Ca2+ signaling and contractility in response to ß-adrenergic stimulation in the myocardium.


Subject(s)
Adrenergic Agents , Protein Phosphatase 2 , Adrenergic Agents/metabolism , Adrenergic Agents/pharmacology , Animals , Calcium/metabolism , Isoproterenol/pharmacology , Mice , Mice, Knockout , Myocardial Contraction , Myocytes, Cardiac/metabolism , Phosphorylation , Protein Phosphatase 2/genetics , Protein Phosphatase 2/metabolism , Sarcoplasmic Reticulum/metabolism
4.
Int J Mol Sci ; 23(15)2022 Aug 05.
Article in English | MEDLINE | ID: mdl-35955861

ABSTRACT

Prader−Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by the deletion or inactivation of paternally expressed imprinted genes at the chromosomal region 15q11−q13. The PWS-critical region (PWScr) harbors tandemly repeated non-protein coding IPW-A exons hosting the intronic SNORD116 snoRNA gene array that is predominantly expressed in brain. Paternal deletion of PWScr is associated with key PWS symptoms in humans and growth retardation in mice (PWScr model). Dysregulation of the hypothalamic−pituitary axis (HPA) is thought to be causally involved in the PWS phenotype. Here we performed a comprehensive reverse transcription quantitative PCR (RT-qPCR) analysis across nine different brain regions of wild-type (WT) and PWScr mice to identify stably expressed reference genes. Four methods (Delta Ct, BestKeeper, Normfinder and Genorm) were applied to rank 11 selected reference gene candidates according to their expression stability. The resulting panel consists of the top three most stably expressed genes suitable for gene-expression profiling and comparative transcriptome analysis of WT and/or PWScr mouse brain regions. Using these reference genes, we revealed significant differences in the expression patterns of Igfbp7, Nlgn3 and three HPA associated genes: Pcsk1, Pcsk2 and Nhlh2 across investigated brain regions of wild-type and PWScr mice. Our results raise a reasonable doubt on the involvement of the Snord116 in posttranscriptional regulation of Nlgn3 and Nhlh2 genes. We provide a valuable tool for expression analysis of specific genes across different areas of the mouse brain and for comparative investigation of PWScr mouse models to discover and verify different regulatory pathways affecting this complex disorder.


Subject(s)
Prader-Willi Syndrome , Animals , Basic Helix-Loop-Helix Transcription Factors/metabolism , Brain/metabolism , Disease Models, Animal , Exons , Genomic Imprinting , Humans , Mice , Prader-Willi Syndrome/genetics , Prader-Willi Syndrome/metabolism , Proprotein Convertase 1/genetics , Proprotein Convertase 1/metabolism , RNA, Small Nucleolar/genetics , RNA, Small Nucleolar/metabolism
5.
Int J Mol Sci ; 23(13)2022 Jun 23.
Article in English | MEDLINE | ID: mdl-35805995

ABSTRACT

The dysregulation of microRNAs (miRNAs) has been known to play important roles in tumor development and progression. However, the understanding of the involvement of miRNAs in regulating tumor-associated macrophages (TAMs) and how these TAM-related miRNAs (TRMs) modulate cancer progression is still in its infancy. This study aims to explore the prognostic value of TRMs in breast cancer via the construction of a novel TRM signature. Potential TRMs were identified from the literature, and their prognostic value was evaluated using 1063 cases in The Cancer Genome Atlas Breast Cancer database. The TRM signature was further validated in the external Gene Expression Omnibus GSE22220 dataset. Gene sets enrichment analyses were performed to gain insight into the biological functions of this TRM signature. An eleven-TRM signature consisting of mir-21, mir-24-2, mir-125a, mir-221, mir-22, mir-501, mir-365b, mir-660, mir-146a, let-7b and mir-31 was constructed. This signature significantly differentiated the high-risk group from the low-risk in terms of overall survival (OS)/ distant-relapse free survival (DRFS) (p value < 0.001). The prognostic value of the signature was further enhanced by incorporating other independent prognostic factors in a nomogram-based prediction model, yielding the highest AUC of 0.79 (95% CI: 0.72−0.86) at 5-year OS. Enrichment analyses confirmed that the differentially expressed genes were mainly involved in immune-related pathways such as adaptive immune response, humoral immune response and Th1 and Th2 cell differentiation. This eleven-TRM signature has great potential as a prognostic factor for breast cancer patients besides unravelling the dysregulated immune pathways in high-risk breast cancer.


Subject(s)
Breast Neoplasms , MicroRNAs , Biomarkers, Tumor/genetics , Breast Neoplasms/pathology , Female , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Neoplasm Recurrence, Local , Tumor-Associated Macrophages
6.
Redox Biol ; 48: 102179, 2021 Nov 06.
Article in English | MEDLINE | ID: mdl-34763298

ABSTRACT

3',5'-cyclic guanosine monophosphate (cGMP) is a druggable second messenger regulating cell growth and survival in a plethora of cells and disease states, many of which are associated with hypoxia. For example, in myocardial infarction and heart failure (HF), clinical use of cGMP-elevating drugs improves disease outcomes. Although they protect mice from ischemia/reperfusion (I/R) injury, the exact mechanism how cardiac cGMP signaling is regulated in response to hypoxia is still largely unknown. By monitoring real-time cGMP dynamics in murine and human cardiomyocytes using in vitro and in vivo models of hypoxia/reoxygenation (H/R) and I/R injury combined with biochemical methods, we show that hypoxia causes rapid but partial degradation of cGMP-hydrolyzing phosphodiesterase-3A (PDE3A) protein via the autophagosomal-lysosomal pathway. While increasing cGMP in hypoxia prevents cell death, partially reduced PDE3A does not change the pro-apoptotic second messenger 3',5'-cyclic adenosine monophosphate (cAMP). However, it leads to significantly enhanced protective effects of clinically relevant activators of nitric oxide-sensitive guanylyl cyclase (NO-GC). Collectively, our mouse and human data unravel a new mechanism by which cardiac cGMP improves hypoxia-associated disease conditions.

7.
Genet Med ; 23(9): 1664-1672, 2021 09.
Article in English | MEDLINE | ID: mdl-34040195

ABSTRACT

PURPOSE: Prader-Willi syndrome (PWS) is a neurodevelopmental disorder with hypothalamic dysfunction due to deficiency of imprinted genes located on the 15q11-q13 chromosome. Among them, the SNORD116 gene appears critical for the expression of the PWS phenotype. We aimed to clarify the role of SNORD116 in cellular and animal models with regard to growth hormone therapy (GHT), the main approved treatment for PWS. METHODS: We collected serum and induced pluripotent stem cells (iPSCs) from GH-treated PWS patients to differentiate into dopaminergic neurons, and in parallel used a Snord116 knockout mouse model. We analyzed the expression of factors potentially linked to GH responsiveness. RESULTS: We found elevated levels of circulating IGFBP7 in naive PWS patients, with IGFBP7 levels normalizing under GHT. We found elevated IGFBP7 levels in the brains of Snord116 knockout mice and in iPSC-derived neurons from a SNORD116-deleted PWS patient. High circulating levels of IGFBP7 in PWS patients may result from both increased IGFBP7 expression and decreased IGFBP7 cleavage, by downregulation of the proconvertase PC1. CONCLUSION: SNORD116 deletion affects IGFBP7 levels, while IGFBP7 decreases under GHT in PWS patients. Modulation of the IGFBP7 level, which interacts with IGF1, has implications in the pathophysiology and management of PWS under GHT.


Subject(s)
Induced Pluripotent Stem Cells , Prader-Willi Syndrome , Animals , Growth Hormone , Humans , Mice , Neurons , Prader-Willi Syndrome/drug therapy , Prader-Willi Syndrome/genetics , RNA, Small Nucleolar
8.
Int J Mol Sci ; 22(7)2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33807162

ABSTRACT

Prader-Willi syndrome (PWS) is a neurogenetic multifactorial disorder caused by the deletion or inactivation of paternally imprinted genes on human chromosome 15q11-q13. The affected homologous locus is on mouse chromosome 7C. The positional conservation and organization of genes including the imprinting pattern between mice and men implies similar physiological functions of this locus. Therefore, considerable efforts to recreate the pathogenesis of PWS have been accomplished in mouse models. We provide a summary of different mouse models that were generated for the analysis of PWS and discuss their impact on our current understanding of corresponding genes, their putative functions and the pathogenesis of PWS. Murine models of PWS unveiled the contribution of each affected gene to this multi-facetted disease, and also enabled the establishment of the minimal critical genomic region (PWScr) responsible for core symptoms, highlighting the importance of non-protein coding genes in the PWS locus. Although the underlying disease-causing mechanisms of PWS remain widely unresolved and existing mouse models do not fully capture the entire spectrum of the human PWS disorder, continuous improvements of genetically engineered mouse models have proven to be very powerful and valuable tools in PWS research.


Subject(s)
Disease Models, Animal , Prader-Willi Syndrome/genetics , Prader-Willi Syndrome/metabolism , Animals , Chromosome Mapping/methods , DNA Methylation , Genetic Engineering/methods , Genome , Genomic Imprinting , Humans , Male , Mice , RNA, Small Nucleolar/genetics
9.
Cells ; 9(10)2020 09 29.
Article in English | MEDLINE | ID: mdl-33003364

ABSTRACT

Alzheimer's disease (AD) is an age-related detrimental dementia. Amyloid beta peptides (Aß) play a crucial role in the pathology of AD. In familial AD, Aß are generated from the full-length amyloid beta precursor protein (APP) via dysregulated proteolytic processing; however, in the case of sporadic AD, the mechanism of Aß biogenesis remains elusive. circRNAs are a class of transcripts preferentially expressed in brain. We identified a circRNA harboring the Aß-coding region of the APP gene termed circAß-a. This circular RNA was detected in the brains of AD patients and non-dementia controls. With the aid of our recently established approach for analysis of circRNA functions, we demonstrated that circAß-a is efficiently translated into a novel Aß-containing Aß175 polypeptide (19.2 KDa) in both cultured cells and human brain. Furthermore, Aß175 was shown to be processed into Aß peptides-a hallmark of AD. In summary, our analysis revealed an alternative pathway of Aß biogenesis. Consequently, circAß-a and its corresponding translation product could potentially represent novel therapeutic targets for AD treatment. Importantly, our data point to yet another evolutionary route for potentially increasing proteome complexity by generating additional polypeptide variants using back-splicing of primary transcripts that yield circular RNA templates.


Subject(s)
Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/metabolism , Brain/metabolism , RNA, Circular/genetics , RNA, Circular/metabolism , Alzheimer Disease/genetics , Amyloid beta-Peptides/genetics , Amyloid beta-Protein Precursor/genetics , Animals , Brain/pathology , Cell Line, Tumor , Humans , Internal Ribosome Entry Sites/genetics , Introns , Mass Spectrometry , Mice
10.
Sci Adv ; 6(7): eaax2941, 2020 02.
Article in English | MEDLINE | ID: mdl-32095517

ABSTRACT

CRISPR-Cas9-mediated homology-directed DNA repair is the method of choice for precise gene editing in a wide range of model organisms, including mouse and human. Broad use by the biomedical community refined the method, making it more efficient and sequence specific. Nevertheless, the rapidly evolving technique still contains pitfalls. During the generation of six different conditional knockout mouse models, we discovered that frequently (sometimes solely) homology-directed repair and/or nonhomologous end joining mechanisms caused multiple unwanted head-to-tail insertions of donor DNA templates. Disturbingly, conventionally applied PCR analysis, in most cases, failed to identify these multiple integration events, which led to a high rate of falsely claimed precisely edited alleles. We caution that comprehensive analysis of modified alleles is essential and offer practical solutions to correctly identify precisely edited chromosomes.


Subject(s)
CRISPR-Cas Systems/genetics , DNA/genetics , Gene Editing , Templates, Genetic , Animals , Crosses, Genetic , Female , Gene Targeting , Genetic Loci , Genome , Male , Mice, Inbred C57BL , Mice, Knockout , Models, Animal
11.
Food Chem ; 309: 125654, 2020 Mar 30.
Article in English | MEDLINE | ID: mdl-31678669

ABSTRACT

A specialized DNA extraction method and a SYBR Green quantitative polymerase chain reaction (SyG-qPCR) assay were combined to generate a ready-to-use kit for rapid detection of porcine admixtures in processed meat products. Our qPCR assay utilized repetitive LINE-1 elements specific to the genome of Sus scrofa domesticus (pig) as a target and incorporated internal controls. We improved the genomic DNA extraction method, and reduced extraction times to the minimum. The method was validated for specificity, sensitivity (0.001% w/w) and robustness, and values were compared with those of a commercially available kit. We also tested our method using 121 processed food products and consistently detected amplification only in samples containing pork. Due to its efficiency and cost-effectiveness, our method represents a valuable new method for detecting food adulteration with pork that is superior to existing quality control approaches.


Subject(s)
DNA/analysis , Food Contamination/analysis , Organic Chemicals/chemistry , Real-Time Polymerase Chain Reaction/methods , Animals , Benzothiazoles , DNA/isolation & purification , DNA/standards , Diamines , Long Interspersed Nucleotide Elements/genetics , Meat Products/analysis , Quality Control , Quinolines , Real-Time Polymerase Chain Reaction/instrumentation , Sus scrofa/genetics , Swine
12.
Nucleic Acids Res ; 48(2): 719-735, 2020 01 24.
Article in English | MEDLINE | ID: mdl-31740957

ABSTRACT

Mechanisms that ensure repair of double-strand DNA breaks (DSBs) are instrumental in the integration of foreign DNA into the genome of transgenic organisms. After pronuclear microinjection, exogenous DNA is usually found as a concatemer comprising multiple co-integrated transgene copies. Here, we investigated the contribution of various DSB repair pathways to the concatemer formation. We injected mouse zygotes with a pool of linear DNA molecules carrying unique barcodes at both ends and obtained 10 transgenic embryos with 1-300 transgene copies. Sequencing the barcodes allowed us to assign relative positions to the copies in concatemers and detect recombination events that occurred during integration. Cumulative analysis of approximately 1,000 integrated copies reveals that over 80% of them underwent recombination when their linear ends were processed by synthesis-dependent strand annealing (SDSA) or double-strand break repair (DSBR). We also observed evidence of double Holliday junction (dHJ) formation and crossing over during the concatemer formations. Sequencing indels at the junctions between copies shows that at least 10% of DNA molecules introduced into the zygotes are ligated by non-homologous end joining (NHEJ). Our barcoding approach, verified with Pacific Biosciences Single Molecule Real-Time (SMRT) long-range sequencing, documents high activity of homologous recombination after DNA microinjection.


Subject(s)
DNA Breaks, Double-Stranded , DNA/chemistry , Homologous Recombination/genetics , Transgenes/genetics , Animals , Animals, Genetically Modified , DNA/genetics , DNA Barcoding, Taxonomic , DNA End-Joining Repair/genetics , DNA Repair/genetics , DNA, Cruciform/chemistry , DNA, Cruciform/genetics , Mice , Zygote/growth & development
13.
Sci Rep ; 9(1): 14161, 2019 Oct 02.
Article in English | MEDLINE | ID: mdl-31578377

ABSTRACT

In a previous study using one-step CRISPR/Cas9 genome editing in mouse zygotes, we created five founders carrying a 1,137 kb deletion and two founders carrying the same deletion, plus a 2,274 kb duplication involving the Cntn6 gene (encoding contactin-6). Using these mice, the present study had the following aims: (i) to establish stage of origin of these rearrangements; (ii) to determine the fate of the deleted DNA fragments; and (iii) to estimate the scale of unpredicted DNA changes accompanying the rearrangements. The present study demonstrated that all targeted deletions and duplications occurred at the one-cell stage and more often in one pronucleus only. FISH analysis revealed that there were no traces of the deleted DNA fragments either within chromosome 6 or on other chromosomes. These data were consistent with the Southern blot analysis showing that chromosomes with deletion often had close to expected sizes of removed DNA fragments. High-throughput DNA sequencing of two homozygotes for duplication demonstrated that there were no unexpected significant or scale DNA changes either at the gRNA and joint sites or other genome sites. Thus, our data suggested that CRISPR/Cas9 technology could generate megabase-sized deletions and duplications in mouse gametes at a reasonably specific level.


Subject(s)
Cell Adhesion Molecules, Neuronal/genetics , Gene Deletion , Gene Duplication , Animals , CRISPR-Cas Systems , Cells, Cultured , Chromosomes/genetics , Germ Cells/metabolism , Homozygote , Mice , Mice, Inbred C57BL
14.
Sci Rep ; 9(1): 11684, 2019 08 12.
Article in English | MEDLINE | ID: mdl-31406268

ABSTRACT

Circular RNAs (circRNAs) are an emerging class of RNA molecules that have been linked to human diseases and important regulatory pathways. Their functional roles are still under investigation, often hampered by inefficient circRNA formation in and ex vivo. We generated an intron-mediated enhancement (IME) system that-in comparison to previously published methods-increases circRNA formation up to 5-fold. This strategy also revealed previously undetected translation of circRNA, e.g., circRtn4. Substantiated by Western blots and mass spectrometry we showed that in mammalian cells, translation of circRtn4 containing a potential "infinite" circular reading frame resulted in "monomers" and extended proteins, presumably "multimer" tandem repeats. In order to achieve high levels of circRNA formation and translation of other natural or recombinant circRNAs, we constructed a versatile circRNA expression vector-pCircRNA-DMo. We demonstrated the general applicability of this method by efficiently generating two additional circRNAs exhibiting high expression levels. The circRNA expression vector will be an important tool to investigate different aspects of circRNA biogenesis and to gain insights into mechanisms of circular RNA translation.


Subject(s)
Gene Expression Regulation , MicroRNAs/genetics , Protein Biosynthesis , RNA, Circular/genetics , RNA, Messenger/genetics , Animals , Base Sequence , Cell Line, Tumor , Exons , HEK293 Cells , Humans , Introns , Mice , MicroRNAs/metabolism , Neurons/cytology , Neurons/metabolism , Nucleic Acid Conformation , Plasmids/chemistry , Plasmids/metabolism , RNA, Circular/chemistry , RNA, Circular/metabolism , RNA, Messenger/metabolism
15.
Iran J Microbiol ; 11(2): 181-186, 2019 Apr.
Article in English | MEDLINE | ID: mdl-31341574

ABSTRACT

BACKGROUND AND OBJECTIVES: Pfu DNA polymerase is an enzyme that exhibits the lowest error rate in the 3' to 5' exonuclease (proofreading) activity during DNA synthesis in Polymerase Chain Reactions (PCRs). This study was aimed to express and purify Pfu DNA polymerase in a bacterial expression system under a simple purification method. MATERIALS AND METHODS: Pfu polymerase gene sequence, derived from Pyrocuccus furiosus (Pfu) genomic DNA, was cloned and overexpressed in E. coli BL21 (DE3) pLysS. Upon overexpression, bacterial lysate containing the Pfu DNA polymerase was heated at 94°C for 5 minutes. Pfu DNA polymerase having high thermal stability was retained while the other bacterial proteins were denatured. The resulting thermo stable Pfu DNA polymerase was separated from the other debris of the denatured proteins by simple centrifugation. RESULTS: The enzymatic activity of the resulting Pfu DNA polymerase was estimated by comparing with the commercial Pfu DNA Polymerases. An estimated 50000 units of functional Pfu DNA polymerase was produced from a 400 ml culture. CONCLUSION: The in-house produced Pfu DNA Polymerase could be used for routine amplification that requires high-fidelity such as cloning and DNA sequencing.

16.
Am J Trop Med Hyg ; 100(6): 1328-1334, 2019 06.
Article in English | MEDLINE | ID: mdl-30963989

ABSTRACT

The diarrheal disease "cholera" is caused by Vibrio cholerae, and is primarily confined to endemic regions, mostly in Africa and Asia. It is punctuated by outbreaks and creates severe challenges to public health. The disease-causing strains are most-often members of serogroups O1 and O139. PCR-based methods allow rapid diagnosis of these pathogens, including the identification of their biotypes. However, this necessitates the selection of specific target sequences to differentiate even the closely related biotypes of V. cholerae. Oligonucleotides for selective amplification of small RNA (sRNA) genes that are specific to these V. cholerae subtypes were designed. The resulting multiplex PCR assay was validated using V. cholerae cultures (i.e., 19 V. cholerae and 22 non-V. cholerae isolates) and spiked stool samples. The validation using V. cholerae cultures and spiked stool suspensions revealed detection limits of 10-100 pg DNA per reaction and 1.5 cells/mL suspension, respectively. The multiplex PCR assay that targets sRNA genes for amplification enables the sensitive and specific detection, as well as the differentiation of V. cholerae-O1 classical, O1 El Tor, and O139 biotypes. Most importantly, the assay enables fast and cheaper diagnosis compared with classic culture-based methods.


Subject(s)
Bacterial Typing Techniques/methods , Multiplex Polymerase Chain Reaction , RNA, Bacterial/genetics , Vibrio cholerae/classification , Vibrio cholerae/genetics , DNA, Bacterial/genetics , Feces/microbiology , Humans
17.
Sci Rep ; 9(1): 4300, 2019 03 12.
Article in English | MEDLINE | ID: mdl-30862860

ABSTRACT

Serotonin 5-HT2C receptor is a G-protein coupled excitatory receptor that regulates several biochemical pathways and has been implicated in obesity, mental state, sleep cycles, autism, neuropsychiatric disorders and neurodegenerative diseases. The activity of 5-HT2CR is regulated via alternative splicing and A to I editing of exon Vb of its pre-mRNA. Snord115 is a small nucleolar RNA that is expressed in mouse neurons and displays an 18-nucleotide base complementary to exon Vb of 5-HT2CR pre-mRNA. For almost two decades this putative guide element of Snord115 has wandered like a ghost through the literature in attempts to elucidate the biological significance of this complementarity. In mice, Snord115 is expressed in neurons and absent in the choroid plexus where, in contrast, 5-Ht2cr mRNA is highly abundant. Here we report the analysis of 5-Ht2cr pre-mRNA posttranscriptional processing via RNA deep sequencing in a mouse model that ectopically expresses Snord115 in the choroid plexus. In contrast to previous reports, our analysis demonstrated that Snord115 does not control alternative splicing of 5-Ht2cr pre-mRNA in vivo. We identified a modest, yet statistically significant reduction of 5-Ht2cr pre-mRNA A to I editing at the major A, B, C and D sites. We suggest that Snord115 and exon Vb of 5Ht2cr pre-mRNA form a double-stranded structure that is subject to ADAR-mediated A to I editing. To the best of our knowledge, this is the first comprehensive Snord115 gain-of-function analysis based on in vivo mouse models.


Subject(s)
RNA, Small Nucleolar/metabolism , Alternative Splicing/genetics , Alternative Splicing/physiology , Animals , Choroid Plexus/metabolism , Female , Genotype , Male , Mice , Mice, Mutant Strains , RNA Editing/genetics , RNA Editing/physiology , RNA Splicing/genetics , RNA Splicing/physiology , RNA, Small Nucleolar/genetics
18.
Crit Rev Biochem Mol Biol ; 53(4): 335-355, 2018 08.
Article in English | MEDLINE | ID: mdl-29793351

ABSTRACT

Over the past decade, RNA-deep sequencing has uncovered copious non-protein coding RNAs (npcRNAs) in bacteria. Many of them are key players in the regulation of gene expression, taking part in various regulatory circuits, such as metabolic responses to different environmental stresses, virulence, antibiotic resistance, and host-pathogen interactions. This has contributed to the high adaptability of bacteria to changing or even hostile environments. Their mechanisms include the regulation of transcriptional termination, modulation of translation, and alteration of messenger RNA (mRNA) stability, as well as protein sequestration. Here, the mechanisms of gene expression by regulatory bacterial npcRNAs are comprehensively reviewed and supplemented with well-characterized examples. This class of molecules and their mechanisms of action might be useful targets for the development of novel antibiotics.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacteria , Bacterial Infections/drug therapy , Drug Delivery Systems/methods , RNA, Bacterial , RNA, Untranslated , Animals , Bacteria/genetics , Bacteria/metabolism , Bacterial Infections/genetics , Bacterial Infections/metabolism , Gene Expression Regulation, Bacterial/physiology , High-Throughput Nucleotide Sequencing , Humans , RNA, Bacterial/biosynthesis , RNA, Bacterial/genetics , RNA, Untranslated/biosynthesis , RNA, Untranslated/genetics
19.
J Nucleic Acids ; 2017: 3712070, 2017.
Article in English | MEDLINE | ID: mdl-29225967

ABSTRACT

The binding specificity and affinity of aptamers have long been harnessed as the key elements in the development of aptamer-based assays, particularly aptasensing application. One promising avenue that is currently explored based on the specificity and affinity of aptamers is the application of aptamers in the decontamination assays. Aptamers have been successfully harnessed as the decontamination agents to remove contaminants from the environment and to decontaminate infectious elements. The reversible denaturation property inherent in aptamers enables the repeated usage of aptamers, which can immensely save the cost of decontamination. Analogous to the point-of-care diagnostics, there is no doubt that aptamers can also be deployed in the point-of-care aptamer-based decontamination assay, whereby decontamination can be performed anywhere and anytime for instantaneous decision-making. It is also prophesied that aptamers can also serve more than as a decontaminant, probably as a tool to capture and kill hazardous elements, particularly pathogenic agents.

20.
J Cell Mol Med ; 21(10): 2276-2283, 2017 10.
Article in English | MEDLINE | ID: mdl-28756649

ABSTRACT

Technological advances in RNA biology greatly improved transcriptome profiling during the last two decades. Besides the discovery of many small RNAs (sRNA) that are involved in the physiological and pathophysiological regulation of various cellular circuits, it becomes evident that the corresponding RNA genes might also serve as potential biomarkers to monitor the progression of disease and treatment. sRNA gene candidate npcTB_6715 was previously identified via experimental RNomic (unpublished data), and we report its application as potential biomarker for the detection of Mycobacterium tuberculosis (MTB) in patient samples. For proof of principle, we developed a multiplex PCR assay and report its validation with 500 clinical cultures, positive for Mycobacteria. The analysis revealed 98.9% sensitivity, 96.1% specificity, positive and negative predictive values of 98.6% and 96.8%, respectively. These results underscore the diagnostic value of the sRNA gene as diagnostic marker for the specific detection of MTB in clinical samples. Its successful application and the general ease of PCR-based detection compared to standard bacterial culture techniques might be the first step towards 'point-of-care' diagnostics of Mycobacteria. To the best of our knowledge, this is the first time for the design of diagnostic applications based on sRNA genes, in Mycobacteria.


Subject(s)
Biomarkers/metabolism , Mycobacterium tuberculosis/genetics , RNA, Bacterial/genetics , RNA, Small Untranslated/genetics , RNA/genetics , DNA, Complementary/chemistry , DNA, Complementary/genetics , Gene Expression Profiling/methods , Genomics/methods , Humans , Multiplex Polymerase Chain Reaction/methods , Mycobacterium tuberculosis/physiology , Reproducibility of Results , Sensitivity and Specificity , Sequence Analysis, DNA/methods , Tuberculosis/diagnosis , Tuberculosis/microbiology
SELECTION OF CITATIONS
SEARCH DETAIL
...