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1.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 869-872, 2021 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-34487533

RESUMO

OBJECTIVE: To identify the etiology of a patient with severe symptoms of DMD and to trace its pathogenic gene, so as to provide a basis for genetic counseling and clinical intervention. METHODS: Multiple ligation-dependent probe amplification (MLPA) technique was used to analyze exon deletion/repetitive variant of DMD gene, and further analysis was performed by chromosome G-banding, fluorescence in situ hybridization (FISH) and SNP array analysis. RESULTS: The MLPA results of the proband showed that the exon 1-79 of DMD gene were deleted, the G-banding karyotype of blood sample was 46, XY, and the deletion of the short arm of X chromosome was found by FISH. SNP array results showed that 5.8Mb (29 628 158-35 434 714) deletion occurred in the Xp21.2p21.1 region of X chromosome, and the patient was diagnosed as the contiguous deletion syndrome involving the genes of IL1RAPL, MAGEB1-4, ROB, CXorf2, GM, AP3K7IP, FTHL1, DMD, FAM47A, TMEM47, and FAM47B. CONCLUSION: The exact pathogenic site of this family is the deletion of 5.8 Mb (29 628 158-35 434 714) in the Xp21.2p21.1 region of X chromosome, which can be used for prenatal diagnosis. High resolution SNP array technique plays an important role in detecting potential chromosome abnormalities in patients.


Assuntos
Distrofia Muscular de Duchenne , Distrofina/genética , Éxons , Feminino , Deleção de Genes , Humanos , Hibridização in Situ Fluorescente , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/genética , Gravidez , Diagnóstico Pré-Natal
2.
Medicina (B Aires) ; 81(4): 574-580, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34453799

RESUMO

The growth hormone receptor (GHR) mediates the effect of growth hormone (GH) on linear growth and metabolism. In humans, it exists as two isoforms differing by the retention or exclusion of exon 3; a full-length GHR isoform (GHRfl) and the exon 3-deleted isoform (GHRd3). The genotypic frequency of this polymorphism was analyzed in several studies and in different human populations. However scarce information in Argentinean population is available. Associations between GHRd3 and growth have been reported previously. Some studies have shown that the presence of GHRd3 polymorphism might be a potential variant that improves growth response to recombinant human GH (rhGH) therapy in patients born small for gestational age (SGA), among others. However, over the years the results have been controversial and inconclusive. Based on this, it would be proposed that variants at the genomic level are not completely reflected at the mRNA level. Our aim was to evaluate the genotypic frequencies (%) of the GHR gene polymorphism (GHRfl/GHRfl; GHRfl/GHRd3; GHRd3/GHRd3) in normal Argentinean population (n = 94) and SGA patients (n = 65), and the expression of these polymorphisms at mRNA level in the fetal side of placenta tissues was analyzed. In addition, their association with spontaneous postnatal catch-up growth in SGA patients was also evaluated. In this study, we show a significant increment of compensatory growth in small for gestational age children (SGA) associated to the presence of the GHRd3 allele polymorphism. In addition, the expression of GHR in healthy placentas revealed that no alternative splicing mechanism occurs.


Assuntos
Hormônio do Crescimento Humano , Receptores da Somatotropina , Proteínas de Transporte , Criança , Éxons , Feminino , Idade Gestacional , Humanos , Polimorfismo Genético , Gravidez , Receptores da Somatotropina/genética
3.
BMC Plant Biol ; 21(1): 376, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34399701

RESUMO

BACKGROUND: Glycolytic pathway is common in all plant organs, especially in oxygen-deficient tissues. Phosphofructokinase (PFK) is a rate-limiting enzyme in the glycolytic pathway and catalyses the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate. Cassava (M. esculenta) root is a huge storage organ with low amount of oxygen. However, less is known about the functions of PFK from M. esculenta (MePFK). We conducted a systematic analysis of MePFK genes to explore the function of the MePFK gene family under hypoxic stress. RESULTS: We identified 13 MePFK genes and characterised their sequence structure. The phylogenetic tree divided the 13 genes into two groups: nine were MePFKs and four were pyrophosphate-fructose-6-phosphate phosphotransferase (MePFPs). We confirmed by green fluorescent protein fusion protein expression that MePFK03 and MePFPA1 were localised in the chloroplast and cytoplasm, respectively. The expression profiles of the 13 MePFKs detected by quantitative reverse transcription polymerase chain reaction revealed that MePFK02, MePFK03, MePFPA1, MePFPB1 displayed higher expression in leaves, root and flower. The expression of MePFK03, MePFPA1 and MePFPB1 in tuber root increased gradually with plant growth. We confirmed that hypoxia occurred in the cassava root, and the concentration of oxygen was sharply decreasing from the outside to the inside root. The expression of MePFK03, MePFPA1 and MePFPB1 decreased with the decrease in the oxygen concentration in cassava root. Waterlogging stress treatment showed that the transcript level of PPi-dependent MePFP and MeSuSy were up-regulated remarkably and PPi-dependent glycolysis bypass was promoted. CONCLUSION: A systematic survey of phylogenetic relation, molecular characterisation, chromosomal and subcellular localisation and cis-element prediction of MePFKs were performed in cassava. The expression profiles of MePFKs in different development stages, organs and under waterlogging stress showed that MePFPA1 plays an important role during the growth and development of cassava. Combined with the transcriptional level of MeSuSy, we found that pyrophosphate (PPi)-dependent glycolysis bypass was promoted when cassava was under waterlogging stress. The results would provide insights for further studying the function of MePFKs under hypoxic stress.


Assuntos
Genoma de Planta , Manihot/enzimologia , Manihot/genética , Fosfofrutoquinases/genética , Fosfofrutoquinases/metabolismo , Cloroplastos/enzimologia , Mapeamento Cromossômico , Cromossomos de Plantas , Sequência Conservada , Citoplasma/enzimologia , Éxons , Flores/enzimologia , Íntrons , Família Multigênica , Oxigênio/metabolismo , Filogenia , Folhas de Planta/enzimologia , Raízes de Plantas/enzimologia , Regiões Promotoras Genéticas , Estresse Fisiológico/genética , Transcriptoma
4.
BMC Genomics ; 22(1): 586, 2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344317

RESUMO

BACKGROUND: Circular RNAs (circRNAs) play diverse roles in different biological and physiological environments and are always expressed in a tissue-specific manner. Especially, circRNAs are enriched in the brain tissues of almost all investigated species, including humans, mice, Drosophila, etc. Although circRNAs were found in C. elegans, the neuron-specific circRNA data is not available yet. Exon-skipping is found to be correlated to circRNA formation, but the mechanisms that link them together are not clear. RESULTS: Here, through large-scale neuron isolation from the first larval (L1) stage of C. elegans followed by RNA sequencing with ribosomal RNA depletion, the neuronal circRNA data in C. elegans were obtained. Hundreds of novel circRNAs were annotated with high accuracy. circRNAs were highly expressed in the neurons of C. elegans and were positively correlated to the levels of their cognate linear mRNAs. Disruption of reverse complementary match (RCM) sequences in circRNA flanking introns effectively abolished circRNA formation. In the zip-2 gene, deletion of either upstream or downstream RCMs almost eliminated the production of both the circular and the skipped transcript. Interestingly, the 13-nt RCM in zip-2 is highly conserved across five nematode ortholog genes, which show conserved exon-skipping patterns. Finally, through in vivo one-by-one mutagenesis of all the splicing sites and branch points required for exon-skipping and back-splicing in the zip-2 gene, I showed that back-splicing still happened without exon-skipping, and vice versa. CONCLUSIONS: Through protocol optimization, total RNA obtained from sorted neurons is increased to hundreds of nanograms. circRNAs highly expressed in the neurons of C. elegans are more likely to be derived from genes also highly expressed in the neurons. RCMs are abundant in circRNA flanking introns, and RCM-deletion is an efficient way to knockout circRNAs. More importantly, these RCMs are not only required for back-splicing but also promote the skipping of exon(s) to be circularized. Finally, RCMs in circRNA flanking introns can directly promote both exon-skipping and back-splicing, providing a new explanation for the correlation between them.


Assuntos
Caenorhabditis elegans , RNA , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Éxons , Camundongos , RNA/metabolismo , Splicing de RNA , RNA Circular
5.
Zhonghua Er Ke Za Zhi ; 59(8): 678-683, 2021 Aug 02.
Artigo em Chinês | MEDLINE | ID: mdl-34333921

RESUMO

Objective: To investigate the clinical and genetic features, and treatment of X-linked hypophosphatemic rickets (XLH). Methods: In this retrospective study, we reviewed the medical records of 25 pediatric patients with XLH who were admitted to Department of Endocrinology Genetics and Metabolism,Beijing Children's Hospital from January 2010 to January 2020. The clinical characteristics, PHEX gene variants, as well as clinical outcome of the patients were summarized. To analyze the correlation between genotype and phenotype, the patients were divided into different subgroups according to the location of the variants, including N-terminal-located vs. C-terminal-located variant, and Zn-binding domain exon 17 or 19 variant vs. non-exon 17 or 19 variant. The age at onset, height standard deviation score (HtSDS), intercondylar or intermalleolar distance, fasting serum phosphorus, and HtSDS and intercondylar or intermalleolar distance at the final follow-up were compared by rank sum test or t text. Results: Among the 25 children with XLH, 8 were boys and 17 were girls. The median age of onset was 1.2 (1.0, 1.8) years, and the median age of diagnosis was 2.5 (1.5, 4.3) years. The main clinical manifestations were abnormal gait and lower limb deformity. The HtSDS was -2.0(-3.2, -0.8), and the intercondylar or intermalleolar distance was 4.5 (3.0, 6.0) cm. The fasting serum phosphorus level was 0.8 (0.7, 0.9) mmol/L, while the serum alkaline phosphatase level was (721±41) U/L and the serum calcium level was (2.5±0.1) mmol/L. Three patients (12%) had parathyroid hormone levels above the upper limit of the normal range. Twenty-five patients (100%) showed radiographic changes of active rickets. Nephrocalcinosis was found in 2 cases (9%). Twenty-four different PHEX variations were detected in 25 patients, among whom 11 (44%) had not been reported previously. No hot spot variation was found. No statistical differences (all P>0.05) were identified in clinical features and outcomes either in comparing patients with N-terminal (21 cases) and C-terminal (4 cases) variants, or in comparing patients with variant located in exon 17 or 19 (4 cases) or not (21 cases). Twenty-four cases (96%) were treated regularly with phosphate supplements and active vitamin D. After 2.7 (1.6, 5.0) years of follow-up, clinical symptoms were relieved in 96% (24/25) of the patients. The HtSDS after treatment had no significant difference compared to that before treatment (-2.0(-3.2, -0.8) vs.-2.0(-2.8, -1.1),Z =-0.156, P>0.05), while the intercondylar or intermalleolar distance after treatment was significantly reduced compared to that before treatment (4.5(3.0, 6.0) vs. 1.5(0, 3.3) cm, Z =-3.043, P<0.05). Bone X-rays were reexamined in 17 cases after treatment, and radiographic signs of rickets were improved. Eighteen cases had secondary hyperparathyroidism and 7 cases had nephrocalcinosis. Conclusions: The main clinical manifestations of XLH are abnormal gait, lower limb deformity and short stature. A high proportion of novel variations of PHEX gene but no hot spot variation neither genotype-phenotype correlation are found. Regular treatment with phosphate supplements and active vitamin D can significantly improve the symptoms except for the height. However, the rate of adverse events including secondary hyperparathyroidism and nephrocalcinosis seems to be high.


Assuntos
Raquitismo Hipofosfatêmico Familiar , Doenças Genéticas Ligadas ao Cromossomo X , Criança , Pré-Escolar , Éxons , Raquitismo Hipofosfatêmico Familiar/genética , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/genética , Humanos , Lactente , Masculino , Endopeptidase Neutra Reguladora de Fosfato PHEX/genética , Fenótipo , Estudos Retrospectivos
6.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(8): 727-730, 2021 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-34365611

RESUMO

OBJECTIVE: To identify the pathogenic variants of 4 patients with hemolytic anemia of unknown cause. METHODS: Peripheral blood samples of the patients and their family members were collected to extract DNA. The coding region and splice region in all exons of gene of erythrocyte related diseases were analyzed by using target sequence capture and high-throughput sequencing technology. Suspected pathogenic variants were verified by PCR combined Sanger sequencing technology. RESULTS: Each of the probands was detected two compound heterozygous variants, and CDA II was diagnosed. Six variants were detected in the 4 probands, four variants were reported and the other two were first reported. CONCLUSION: By high-throughput sequencing, gene variant of CDA II be analyzed fast and accurately. It is an effective supplement to convenional diagnostic methods. Furthermore, the novel variant sites have enriched the variant database of the SEC23B gene.


Assuntos
Anemia Diseritropoética Congênita , Anemia Diseritropoética Congênita/genética , Éxons/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação , Proteínas de Transporte Vesicular/genética
7.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(8): 807-808, 2021 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-34365631

RESUMO

OBJECTIVE: To determine the genotype of an individual suspected for Aw through DNA sequencing. METHODS: Serologic testing was carried out with standard methods. Exons 6 and 7 of the ABO genes were amplified by PCR and subjected to direct sequencing or sequenced after gene cloning. RESULTS: Serological testing showed that the forward typing and reverse typing were Aw and A, respectively. DNA sequencing revealed that the individual has carried an Aw allele and an O allele. Haplotype sequencing of each allele has revealed a nt543 variant (543G>C) in the Aw allele. CONCLUSION: The individual was verified as a rare A subtype, which was previously unreported in mainland China.


Assuntos
Sistema ABO de Grupos Sanguíneos , Sistema ABO de Grupos Sanguíneos/genética , Alelos , Éxons , Genótipo , Humanos , Fenótipo
8.
Anal Methods ; 13(34): 3837-3844, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34378562

RESUMO

Recent studies suggest that breast cancer cells express various CD44 isoforms. CD44 is an integral transmembrane protein encoded by a single 20-exon gene. Exon v10 of CD44 plays a critical role in promoting cancer metastasis, so sensitive detection of this isoform helps in early diagnosis of metastatic breast cancer and facilitates the treatment process. This study aimed to use v10-specific aptamers to set up an optical aptasensor based on fluorescent metal nanoclusters. For this purpose, nanoclusters of silver, gold, and copper were prepared by different CD44 v10 DNA aptamers as molecular templates. UV-vis, TEM, and fluorescence spectrometer results confirmed the accuracy and quality of the synthesized aptamer-templated nanoclusters (Apt-NCs). Finally, we compared the performance of the as-prepared Apt-NCs in response to different cultured cell lines. According to the results, the optical response of M-Apt4-CuNCs was more efficient and correlated well with the concentrations of CD44 v10-enriched cells. The detection limit of the aptasensor was 40 ± 5 cells per mL.


Assuntos
Aptâmeros de Nucleotídeos , Neoplasias da Mama , Receptores de Hialuronatos , Neoplasias da Mama/diagnóstico , Cobre , Éxons/genética , Feminino , Humanos , Receptores de Hialuronatos/genética , Isoformas de Proteínas/genética
9.
Prog Mol Subcell Biol ; 60: 203-234, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34386877

RESUMO

Here we present three interesting novel human Higher-Order Repeats (HORs) discovered using the HOR-searching method with GRM algorithm: (a) The novel Neuroblastoma Breakpoint Family gene (NBPF) 3mer HOR, discovered applying GRM algorithm to human chromosome 1 (Paar et al., Mol Biol Evol 28:1877-1892, 2011). NBPF 3mer HOR is based on previously known ~1.6 kb NBPF primary repeat monomers (known as DUF1220 domain) in human chromosome 1, but the NBPF HOR was not known before its discovery by using GRM. It should be stressed that the NBPF HOR presents a unique human-specific pattern, distinguishing human from nonhuman primates. (b) The novel quartic HOR (2mer⊃2mer⊃9mer) discovered using the GRM algorithm for analysis of hornerin genes in human chromosome 1 (Paar et al., Mol Biol Evol 28:1877-1892, 2011). This quartic HOR is based on 39 bp hornerin primary repeat monomer in human chromosome 1. To our knowledge, this is the first known case of quartic HOR, with four levels of hierarchy of HOR organization. (c) The novel 33mer alpha satellite HOR in human chromosome 21, discovered using the GRM algorithm (Gluncic et al., Sci Rep 9:12629, 2019). This 33mer HOR in the smallest human chromosome is the largest alpha satellite HOR copy among all 22 somatic human chromosomes. Moreover, the same 33mer HOR is present in the hg38 human genome assembly of four human chromosomes: 21, 22, 13, and 14. We point out that the DUF1220 encoding genomic structures in NBPF genes in human chromosome 1, recently studied and related to the brain evolution and pathologies and cognitive aptitude, can be considered in the framework of the general concept of HORs, already extensively studied in genomics, especially in the centromeric region.


Assuntos
Cromossomos Humanos Par 21 , Neuroblastoma , Animais , Centrômero , DNA Satélite , Éxons , Genoma Humano/genética , Humanos , Neuroblastoma/genética
10.
Nat Commun ; 12(1): 4825, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376658

RESUMO

Circular RNA (circRNA) is a class of covalently joined non-coding RNAs with functional roles in a wide variety of cellular processes. Their composition shows extensive overlap with exons found in linear mRNAs making it difficult to delineate their composition using short-read RNA sequencing, particularly for long and multi-exonic circRNAs. Here, we use long-read nanopore sequencing of nicked circRNAs (circNick-LRS) and characterize a total of 18,266 and 39,623 circRNAs in human and mouse brain, respectively. We further develop an approach for targeted long-read sequencing of a panel of circRNAs (circPanel-LRS), eliminating the need for prior circRNA enrichment and find >30 circRNA isoforms on average per targeted locus. Our data show that circRNAs exhibit a large number of splicing events such as novel exons, intron retention and microexons that preferentially occur in circRNAs. We propose that altered exon usage in circRNAs may reflect resistance to nonsense-mediated decay in the absence of translation.


Assuntos
Encéfalo/metabolismo , Éxons/genética , Íntrons/genética , Sequenciamento por Nanoporos/métodos , RNA Circular/genética , Análise de Sequência de RNA/métodos , Animais , Expressão Gênica , Humanos , Masculino , Camundongos da Linhagem 129 , Isoformas de RNA/genética , Splicing de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(7): 686-689, 2021 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-34247379

RESUMO

OBJECTIVE: To explore the clinical features and genetic basis for a patient diagnosed with creatine deficiency syndrome (CDS). METHODS: The patient was subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. The level of creatine was determined by using a magnetic resonance spectrum (MRS) method. RESULTS: The patient presented with development delay and poor response to stimuli. No obvious abnormality was found with his muscle tone and strength of his limbs. Borderline EEG was detected. MRI showed abnormal development of the white matter and dysplasia of corpus callosum. Urine organic acid screening has shown increased glycerin-3-phosphate. WES revealed that the patient has carried compound heterozygous variants of the GAMT gene, namely c.412C>T and IVS4-1G>A, which were respectively derived from his mother and father. MRS showed reduced creatine in bilateral basal ganglia. Functional study of the splicing site suggested that the IVS4-1G>A variant has resulted skipping of exon 5 upon splicing. CONCLUSION: The compound variants of the GAMT gene probably underlay the disease in this child. Above finding has enriched the spectrum of GAMT gene variants.


Assuntos
Creatina , Criança , Éxons , Humanos , Mutação , Síndrome , Sequenciamento Completo do Exoma
12.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201610

RESUMO

The accumulation of aggregated protein is a typical hallmark of many human neurodegenerative disorders, including polyglutamine-related diseases such as chorea Huntington. Misfolding of the amyloidogenic proteins gives rise to self-assembled complexes and fibres. The huntingtin protein is characterised by a segment of consecutive glutamines which, when exceeding ~ 37 residues, results in the occurrence of the disease. Furthermore, it has also been demonstrated that the 17-residue amino-terminal domain of the protein (htt17), located upstream of this polyglutamine tract, strongly correlates with aggregate formation and pathology. Here, we demonstrate that membrane interactions strongly accelerate the oligomerisation and ß-amyloid fibril formation of htt17-polyglutamine segments. By using a combination of biophysical approaches, the kinetics of fibre formation is investigated and found to be strongly dependent on the presence of lipids, the length of the polyQ expansion, and the polypeptide-to-lipid ratio. Finally, the implications for therapeutic approaches are discussed.


Assuntos
Membrana Celular/metabolismo , Proteína Huntingtina/metabolismo , Peptídeos/metabolismo , Benzotiazóis/química , Dicroísmo Circular , Difusão Dinâmica da Luz , Éxons , Fluorescência , Humanos , Proteína Huntingtina/química , Proteína Huntingtina/genética , Bicamadas Lipídicas , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Peptídeos/química
13.
Nat Commun ; 12(1): 4535, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315877

RESUMO

Retinoblastoma is a childhood cancer of the developing retina that initiates with biallelic inactivation of the RB1 gene. Children with germline mutations in RB1 have a high likelihood of developing retinoblastoma and other malignancies later in life. Genetically engineered mouse models of retinoblastoma share some similarities with human retinoblastoma but there are differences in their cellular differentiation. To develop a laboratory model of human retinoblastoma formation, we make induced pluripotent stem cells (iPSCs) from 15 participants with germline RB1 mutations. Each of the stem cell lines is validated, characterized and then differentiated into retina using a 3-dimensional organoid culture system. After 45 days in culture, the retinal organoids are dissociated and injected into the vitreous of eyes of immunocompromised mice to support retinoblastoma tumor growth. Retinoblastomas formed from retinal organoids made from patient-derived iPSCs have molecular, cellular and genomic features indistinguishable from human retinoblastomas. This model of human cancer based on patient-derived iPSCs with germline cancer predisposing mutations provides valuable insights into the cellular origins of this debilitating childhood disease as well as the mechanism of tumorigenesis following RB1 gene inactivation.


Assuntos
Organoides/patologia , Retina/patologia , Retinoblastoma/patologia , Células-Tronco/patologia , Adulto , Diferenciação Celular , Linhagem Celular , Epigênese Genética , Éxons/genética , Feminino , Genoma Humano , Mutação em Linhagem Germinativa/genética , Humanos , Imageamento Tridimensional , Células-Tronco Pluripotentes Induzidas/metabolismo , Retinoblastoma/genética , Proteína do Retinoblastoma/genética
14.
Nature ; 596(7871): 291-295, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34321659

RESUMO

So far, gene therapies have relied on complex constructs that cannot be finely controlled1,2. Here we report a universal switch element that enables precise control of gene replacement or gene editing after exposure to a small molecule. The small-molecule inducers are currently in human use, are orally bioavailable when given to animals or humans and can reach both peripheral tissues and the brain. Moreover, the switch system, which we denote Xon, does not require the co-expression of any regulatory proteins. Using Xon, the translation of the desired elements for controlled gene replacement or gene editing machinery occurs after a single oral dose of the inducer, and the robustness of expression can be controlled by the drug dose, protein stability and redosing. The ability of Xon to provide temporal control of protein expression can be adapted for cell-biology applications and animal studies. Additionally, owing to the oral bioavailability and safety of the drugs used, the Xon switch system provides an unprecedented opportunity to refine and tailor the application of gene therapies in humans.


Assuntos
Processamento Alternativo/efeitos dos fármacos , Edição de Genes/métodos , Terapia Genética/métodos , Biossíntese de Proteínas/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Proteína 9 Associada à CRISPR/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Eritropoetina/biossíntese , Eritropoetina/genética , Eritropoetina/metabolismo , Éxons/genética , Feminino , Demência Frontotemporal/metabolismo , Células HEK293 , Humanos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atrofia Muscular Espinal/metabolismo , Lipofuscinoses Ceroides Neuronais/metabolismo , Progranulinas/biossíntese , Progranulinas/genética , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Proteína 2 de Sobrevivência do Neurônio Motor/metabolismo
15.
Nat Commun ; 12(1): 4212, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244496

RESUMO

CSR-1 is an essential Argonaute protein that binds to a subclass of 22G-RNAs targeting most germline-expressed genes. Here we show that the two isoforms of CSR-1 have distinct expression patterns; CSR-1B is ubiquitously expressed throughout the germline and during all stages of development while CSR-1A expression is restricted to germ cells undergoing spermatogenesis. Furthermore, CSR-1A associates preferentially with 22G-RNAs mapping to spermatogenesis-specific genes whereas CSR-1B-bound small RNAs map predominantly to oogenesis-specific genes. Interestingly, the exon unique to CSR-1A contains multiple dimethylarginine modifications, which are necessary for the preferential binding of CSR-1A to spermatogenesis-specific 22G-RNAs. Thus, we have discovered a regulatory mechanism for C. elegans Argonaute proteins that allows for specificity of small RNA binding between similar Argonaute proteins with overlapping temporal and spatial localization.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Interferência de RNA , Espermatogênese/genética , Animais , Animais Geneticamente Modificados , Arginina/metabolismo , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Éxons/genética , Feminino , Masculino , Metilação , Oogênese/genética , Ligação Proteica/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno/metabolismo , Processos de Determinação Sexual/genética
16.
BMC Genomics ; 22(1): 492, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193038

RESUMO

BACKGROUND: The accumulation of carotenoids in adipose tissue leading to yellow fat is, in sheep, a heritable recessive trait that can be attributed to a nonsense mutation in the beta-carotene oxygenase 2 (BCO2) gene. However, not all sheep breeds suffering from yellow fat have this nonsense mutation, meaning that other functional mechanisms must exist. We investigated one such breed, the Norwegian spælsau. RESULTS: In spælsau we detected an aberration in BCO2 mRNA. Nanopore sequencing of genomic DNA revealed the insertion of a 7.9 kb endogenous Jaagsiekte Sheep Retrovirus (enJSRV) sequence in the first intron of the BCO2 gene. Close examination of its cDNA revealed that the BCO2 genes first exon was spliced together with enJSRV-sequence immediately downstream of a potential -AG splice acceptor site at enJSRV position 415. The hybrid protein product consists of 29 amino acids coded by the BCO2 exon 1, one amino acid coded by the junction sequence, followed by 28 amino acids arbitrary coded for by the enJSRV-sequence, before a translation stop codon is reached. CONCLUSIONS: Considering that the functional BCO2 protein consists of 575 amino acids, it is unlikely that the 58 amino acid BCO2/enJSRV hybrid protein can display any enzymatic function. The existence of this novel BCO2 allele represents an alternative functional mechanism accounting for BCO2 inactivation and is a perfect example of the potential benefits for searching for structural variants using long-read sequencing data.


Assuntos
Retrovirus Jaagsiekte de Ovinos , Tecido Adiposo , Animais , DNA Complementar , Éxons , Retrovirus Jaagsiekte de Ovinos/genética , Ovinos , Carneiro Doméstico/genética
17.
Nat Commun ; 12(1): 4545, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34315864

RESUMO

In the earliest step of spliceosome assembly, the two splice sites flanking an intron are brought into proximity by U1 snRNP and U2AF along with other proteins. The mechanism that facilitates this intron looping is poorly understood. Using a CRISPR interference-based approach to halt RNA polymerase II transcription in the middle of introns in human cells, we discovered that the nascent 5' splice site base pairs with a U1 snRNA that is tethered to RNA polymerase II during intron synthesis. This association functionally corresponds with splicing outcome, involves bona fide 5' splice sites and cryptic intronic sites, and occurs transcriptome-wide. Overall, our findings reveal that the upstream 5' splice sites remain attached to the transcriptional machinery during intron synthesis and are thus brought into proximity of the 3' splice sites; potentially mediating the rapid splicing of long introns.


Assuntos
Íntrons/genética , Sítios de Splice de RNA/genética , Transcrição Genética , Pareamento de Bases/genética , Sequência de Bases , Éxons/genética , Células HEK293 , Células HeLa , Humanos , Proteínas dos Microfilamentos/genética , RNA Polimerase II/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , RNA Nuclear Pequeno/genética , RNA Nuclear Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Ribonucleoproteína Nuclear Pequena U1/metabolismo , Transcriptoma/genética
18.
Nat Commun ; 12(1): 4161, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230488

RESUMO

Given the pleiotropic nature of coding sequences and that many loci exhibit multiple disease associations, it is within non-coding sequence that disease-specificity likely exists. Here, we focus on joint disorders, finding among replicated loci, that GDF5 exhibits over twenty distinct associations, and we identify causal variants for two of its strongest associations, hip dysplasia and knee osteoarthritis. By mapping regulatory regions in joint chondrocytes, we pinpoint two variants (rs4911178; rs6060369), on the same risk haplotype, which reside in anatomical site-specific enhancers. We show that both variants have clinical relevance, impacting disease by altering morphology. By modeling each variant in humanized mice, we observe joint-specific response, correlating with GDF5 expression. Thus, we uncouple separate regulatory variants on a common risk haplotype that cause joint-specific disease. By broadening our perspective, we finally find that patterns of modularity at GDF5 are also found at over three-quarters of loci with multiple GWAS disease associations.


Assuntos
Éxons , Luxação do Quadril/genética , Luxação do Quadril/metabolismo , Osteoartrite do Joelho/genética , Osteoartrite do Joelho/metabolismo , Animais , Condrócitos , Modelos Animais de Doenças , Regulação da Expressão Gênica , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Fator 5 de Diferenciação de Crescimento/genética , Fator 5 de Diferenciação de Crescimento/metabolismo , Humanos , Camundongos , Fenótipo , Sequências Reguladoras de Ácido Nucleico
19.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204574

RESUMO

Using TSG101 pre-mRNA, we previously discovered cancer-specific re-splicing of mature mRNA that generates aberrant transcripts/proteins. The fact that mRNA is aberrantly re-spliced in various cancer cells implies there must be an important mechanism to prevent deleterious re-splicing on the spliced mRNA in normal cells. We thus postulated that mRNA re-splicing is controlled by specific repressors, and we searched for repressor candidates by siRNA-based screening for mRNA re-splicing activity. We found that knock-down of EIF4A3, which is a core component of the exon junction complex (EJC), significantly promoted mRNA re-splicing. Remarkably, we could recapitulate cancer-specific mRNA re-splicing in normal cells by knock-down of any of the core EJC proteins, EIF4A3, MAGOH, or RBM8A (Y14), implicating the EJC core as the repressor of mRNA re-splicing often observed in cancer cells. We propose that the EJC core is a critical mRNA quality control factor to prevent over-splicing of mature mRNA.


Assuntos
Éxons , Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Precursores de RNA/genética , Splicing de RNA , RNA Mensageiro/genética , Linhagem Celular Tumoral , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Humanos , Modelos Biológicos , Neoplasias/metabolismo , Ligação Proteica , Transporte de RNA , Proteínas de Ligação a RNA/metabolismo
20.
BMJ Case Rep ; 14(6)2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193451

RESUMO

Ataxia with oculomotor apraxia type 2 (AOA2), recently renamed as ATX-SETX, is an autosomal recessive, progressive neurodegenerative disorder belonging to inherited cerebellar ataxias. The pathogenic variants of the SETX gene have been implicated in ATX-SETX. We report the case of a 21-year-old woman presenting with ataxia, oculomotor apraxia and dystonia. She had elevated serum α-fetoprotein (AFP), follicle stimulating hormone (FSH) and luteinising hormone (LH) levels and moderate cerebellar atrophy. On further evaluation, she was found to have premature ovarian failure as well. Multiplex ligation-dependent probe amplification detected a heterozygous deletion in exon 6 of the SETX gene. A combination of cerebellar ataxia, oculomotor apraxia with elevated AFP and cerebellar atrophy are highly suggestive of ATX-SETX. In rare instances, it may be associated with premature ovarian failure with elevated FSH and LH levels, necessitating hormonal survey and fertility evaluation in all patients with ATX-SETX.


Assuntos
Apraxias , Ataxia Cerebelar , Adulto , Apraxias/genética , Ataxia , Ataxia Cerebelar/genética , DNA Helicases , Éxons/genética , Feminino , Humanos , Enzimas Multifuncionais , RNA Helicases/genética , Ataxias Espinocerebelares/congênito , Adulto Jovem
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