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1.
Bull World Health Organ ; 99(7): 486-495, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34248221

RESUMO

Objective: To examine transmission and evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in shipboard quarantine of the Diamond Princess cruise ship. Methods: We obtained the full SARS-CoV-2 genome sequences of 28 samples from the Global Initiative on Sharing All Influenza Data database. The samples were collected between 10 and 25 February 2020 and came for individuals who had been tested for SARS-CoV-2 during the quarantine on the cruise ship. These samples were later sequenced in either Japan or the United States of America. We analysed evolution dynamics of SARS-CoV-2 using computational tools of phylogenetics, natural selection pressure and genetic linkage. Findings: The SARS-CoV-2 outbreak in the cruise most likely originated from either a single person infected with a virus variant identical to the WIV04 isolates, or simultaneously with another primary case infected with a virus containing the 11083G > T mutation. We identified a total of 24 new viral mutations across 64.2% (18/28) of samples, and the virus evolved into at least five subgroups. Increased positive selection of SARS-CoV-2 were statistically significant during the quarantine (Tajima's D: -2.03, P < 0.01; Fu and Li's D: -2.66, P < 0.01; and Zeng's E: -2.37, P < 0.01). Linkage disequilibrium analysis confirmed that ribonucleic acid (RNA) recombination with the11083G > T mutation also contributed to the increase of mutations among the viral progeny. Conclusion: The findings indicate that the 11083G > T mutation of SARS-CoV-2 spread during shipboard quarantine and arose through de novo RNA recombination under positive selection pressure.


Assuntos
COVID-19/genética , SARS-CoV-2/genética , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/transmissão , Bases de Dados de Ácidos Nucleicos , Surtos de Doenças , Hong Kong/epidemiologia , Humanos , Mutação/genética , Filogenia , Quarentena , RNA/genética , SARS-CoV-2/isolamento & purificação , Navios
2.
Nat Commun ; 12(1): 4255, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253720

RESUMO

Homology-directed repair (HDR), a critical DNA repair pathway in mammalian cells, is complex, leading to multiple outcomes with different impacts on genomic integrity. However, the factors that control these different outcomes are often not well understood. Here we show that SWS1-SWSAP1-SPIDR controls distinct types of HDR. Despite their requirement for stable assembly of RAD51 recombinase at DNA damage sites, these proteins are not essential for intra-chromosomal HDR, providing insight into why patients and mice with mutations are viable. However, SWS1-SWSAP1-SPIDR is critical for inter-homolog HDR, the first mitotic factor identified specifically for this function. Furthermore, SWS1-SWSAP1-SPIDR drives the high level of sister-chromatid exchange, promotes long-range loss of heterozygosity often involved with cancer initiation, and impels the poor growth of BLM helicase-deficient cells. The relevance of these genetic interactions is evident as SWSAP1 loss prolongs Blm-mutant embryo survival, suggesting a possible druggable target for the treatment of Bloom syndrome.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Recombinação Homóloga/genética , Complexos Multiproteicos/metabolismo , Animais , Síndrome de Bloom/genética , Síndrome de Bloom/patologia , Proliferação de Células , Células HEK293 , Humanos , Meiose , Camundongos , Mitose , Células-Tronco Embrionárias Murinas/metabolismo , Mutação/genética , Fenótipo , Rad51 Recombinase/metabolismo , Troca de Cromátide Irmã , Análise de Sobrevida
3.
Int J Mol Sci ; 22(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199367

RESUMO

TDP-43 is an RNA-binding protein that has been robustly linked to the pathogenesis of a number of neurodegenerative disorders, including amyotrophic lateral sclerosis and frontotemporal dementia. While mutations in the TARDBP gene that codes for the protein have been identified as causing disease in a small subset of patients, TDP-43 proteinopathy is present in the majority of cases regardless of mutation status. This raises key questions regarding the mechanisms by which TDP-43 proteinopathy arises and spreads throughout the central nervous system. Numerous studies have explored the role of a variety of cellular functions on the disease process, and nucleocytoplasmic transport, protein homeostasis, RNA interactions and cellular stress have all risen to the forefront as possible contributors to the initiation of TDP-43 pathogenesis. There is also a small but growing body of evidence suggesting that aggregation-prone TDP-43 can recruit physiological TDP-43, and be transmitted intercellularly, providing a mechanism whereby small-scale proteinopathy spreads from cell to cell, reflecting the spread of clinical symptoms observed in patients. This review will discuss the potential role of the aforementioned cellular functions in TDP-43 pathogenesis, and explore how aberrant pathology may spread, and result in a feed-forward cascade effect, leading to robust TDP-43 proteinopathy and disease.


Assuntos
Proteínas de Ligação a DNA/genética , Agregação Patológica de Proteínas/genética , Proteínas de Ligação a RNA/genética , Proteinopatias TDP-43/genética , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Humanos , Mutação/genética , Proteinopatias TDP-43/patologia
4.
Int J Mol Sci ; 22(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198929

RESUMO

The molecular mechanisms of insect resistance to Cry toxins generated from the bacterium Bacillus thuringiensis (Bt) urgently need to be elucidated to enable the improvement and sustainability of Bt-based products. Although downregulation of the expression of midgut receptor genes is a pivotal mechanism of insect resistance to Bt Cry toxins, the underlying transcriptional regulation of these genes remains elusive. Herein, we unraveled the regulatory mechanism of the downregulation of the ABC transporter gene PxABCG1 (also called Pxwhite), a functional midgut receptor of the Bt Cry1Ac toxin in Plutella xylostella. The PxABCG1 promoters of Cry1Ac-susceptible and Cry1Ac-resistant strains were cloned and analyzed, and they showed clear differences in activity. Subsequently, a dual-luciferase reporter assay, a yeast one-hybrid (Y1H) assay, and RNA interference (RNAi) experiments demonstrated that a cis-mutation in a binding site of the Hox transcription factor Antennapedia (Antp) decreased the promoter activity of the resistant strain and eliminated the binding and regulation of Antp, thereby enhancing the resistance of P. xylostella to the Cry1Ac toxin. These results advance our knowledge of the roles of cis- and trans-regulatory variations in the regulation of midgut Cry receptor genes and the evolution of Bt resistance, contributing to a more complete understanding of the Bt resistance mechanism.


Assuntos
Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Toxinas de Bacillus thuringiensis/genética , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Receptores de Superfície Celular/genética , Animais , Bacillus thuringiensis/genética , Endotoxinas/genética , Lepidópteros/efeitos dos fármacos , Lepidópteros/genética , Mutação/genética , Regiões Promotoras Genéticas/genética
5.
Int J Mol Sci ; 22(12)2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34199271

RESUMO

Nicotinamide mononucleotide (NMN) is a key intermediate in the nicotinamide adenine dinucleotide (NAD+) biosynthesis. Its supplementation has demonstrated beneficial effects on several diseases. The aim of this study was to characterize NMN deamidase (PncC) inactive mutants to use as possible molecular recognition elements (MREs) for an NMN-specific biosensor. Thermal stability assays and steady-state fluorescence spectroscopy measurements were used to study the binding of NMN and related metabolites (NaMN, Na, Nam, NR, NAD, NADP, and NaAD) to the PncC mutated variants. In particular, the S29A PncC and K61Q PncC variant forms were selected since they still preserve the ability to bind NMN in the micromolar range, but they are not able to catalyze the enzymatic reaction. While S29A PncC shows a similar affinity also for NaMN (the product of the PncC catalyzed reaction), K61Q PncC does not interact significantly with it. Thus, PncC K61Q mutant seems to be a promising candidate to use as specific probe for an NMN biosensor.


Assuntos
Amidoidrolases/genética , Técnicas Biossensoriais , Mutação/genética , Mononucleotídeo de Nicotinamida/metabolismo , Estabilidade Enzimática , Cinética , Mononucleotídeo de Nicotinamida/química , Multimerização Proteica , Espectrometria de Fluorescência , Temperatura , Triptofano/metabolismo
6.
Int J Mol Sci ; 22(12)2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34199295

RESUMO

Spinocerebellar ataxia type 3 (SCA3), a hereditary and lethal neurodegenerative disease, is attributed to the abnormal accumulation of undegradable polyglutamine (polyQ), which is encoded by mutated ataxin-3 gene (ATXN3). The toxic fragments processed from mutant ATXN3 can induce neuronal death, leading to the muscular incoordination of the human body. Some treatment strategies of SCA3 are preferentially focused on depleting the abnormal aggregates, which led to the discovery of small molecule n-butylidenephthalide (n-BP). n-BP-promoted autophagy protected the loss of Purkinje cell in the cerebellum that regulates the network associated with motor functions. We report that the n-BP treatment may be effective in treating SCA3 disease. n-BP treatment led to the depletion of mutant ATXN3 with the expanded polyQ chain and the toxic fragments resulting in increased metabolic activity and alleviated atrophy of SCA3 murine cerebellum. Furthermore, n-BP treated animal and HEK-293GFP-ATXN3-84Q cell models could consistently show the depletion of aggregates through mTOR inhibition. With its unique mechanism, the two autophagic inhibitors Bafilomycin A1 and wortmannin could halt the n-BP-induced elimination of aggregates. Collectively, n-BP shows promising results for the treatment of SCA3.


Assuntos
Autofagia , Doença de Machado-Joseph/tratamento farmacológico , Doença de Machado-Joseph/patologia , Anidridos Ftálicos/uso terapêutico , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Adenilato Quinase/metabolismo , Animais , Ataxina-3/genética , Autofagia/efeitos dos fármacos , Cerebelo/patologia , Feminino , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Doença de Machado-Joseph/fisiopatologia , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Mutação/genética , Anidridos Ftálicos/farmacologia , Agregados Proteicos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células de Purkinje/efeitos dos fármacos , Células de Purkinje/patologia , Transdução de Sinais/efeitos dos fármacos
7.
Int J Mol Sci ; 22(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204776

RESUMO

Point mutations in the genes encoding the skeletal muscle isoforms of tropomyosin can cause a range of muscle diseases. The amino acid substitution of Arg for Pro residue in the 90th position (R90P) in γ-tropomyosin (Tpm3.12) is associated with congenital fiber type disproportion and muscle weakness. The molecular mechanisms underlying muscle dysfunction in this disease remain unclear. Here, we observed that this mutation causes an abnormally high Ca2+-sensitivity of myofilaments in vitro and in muscle fibers. To determine the critical conformational changes that myosin, actin, and tropomyosin undergo during the ATPase cycle and the alterations in these changes caused by R90P replacement in Tpm3.12, we used polarized fluorimetry. It was shown that the R90P mutation inhibits the ability of tropomyosin to shift towards the outer domains of actin, which is accompanied by the almost complete depression of troponin's ability to switch actin monomers off and to reduce the amount of the myosin heads weakly bound to F-actin at a low Ca2+. These changes in the behavior of tropomyosin and the troponin-tropomyosin complex, as well as in the balance of strongly and weakly bound myosin heads in the ATPase cycle may underlie the occurrence of both abnormally high Ca2+-sensitivity and muscle weakness. BDM, an inhibitor of myosin ATPase activity, and W7, a troponin C antagonist, restore the ability of tropomyosin for Ca2+-dependent movement and the ability of the troponin-tropomyosin complex to switch actin monomers off, demonstrating a weakening of the damaging effect of the R90P mutation on muscle contractility.


Assuntos
Contração Muscular/genética , Mutação/genética , Oximas/farmacologia , Sulfonamidas/farmacologia , Tropomiosina/genética , Actinas/metabolismo , Animais , Cálcio/metabolismo , Contração Muscular/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Miofibrilas/efeitos dos fármacos , Miofibrilas/metabolismo , Miosinas/metabolismo , Coelhos , Troponina/metabolismo
8.
Int J Mol Sci ; 22(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204821

RESUMO

Hematologic malignancies comprise a heterogeneous group of neoplasms arising from hematopoietic cells or their precursors and most commonly presenting as leukemias, lymphomas, and myelomas. Genetic analyses have uncovered recurrent mutations which initiate or accumulate in the course of malignant transformation, as they provide selective growth advantage to the cell. These include mutations in genes encoding transcription factors and epigenetic regulators of metabolic genes, as well as genes encoding key metabolic enzymes. The resulting alterations contribute to the extensive metabolic reprogramming characterizing the transformed cell, supporting its increased biosynthetic needs and allowing it to withstand the metabolic stress that arises as a consequence of increased metabolic rates and changes in its microenvironment. Interestingly, this cross-talk is bidirectional, as metabolites also signal back to the nucleus and, via their widespread effects on modulating epigenetic modifications, shape the chromatin landscape and the transcriptional programs of the cell. In this article, we provide an overview of the main metabolic changes and relevant genetic alterations that characterize malignant hematopoiesis and discuss how, in turn, metabolites regulate epigenetic events during this process. The aim is to illustrate the intricate interrelationship between the genome (and epigenome) and metabolism and its relevance to hematologic malignancy.


Assuntos
Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Animais , Epigenoma , Hematopoese/genética , Humanos , Redes e Vias Metabólicas/genética , Modelos Biológicos , Mutação/genética
9.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208111

RESUMO

Anti-PD1/PD-L1 immunotherapy has emerged as a standard of care for stage III-IV non-small cell lung cancer (NSCLC) over the past decade. Patient selection is usually based on PD-L1 expression by tumor cells and/or tumor mutational burden. However, mutations in oncogenic drivers such as EGFR, ALK, BRAF, or MET modify the immune tumor microenvironment and may promote anti-PD1/PD-L1 resistance. In this review, we discuss the molecular mechanisms associated with these mutations, which shape the immune tumor microenvironment and may impede anti-PD1/PD-L1 efficacy. We provide an overview of the current clinical data on anti-PD1/PD-L1 efficacy in NSCLC with oncogenic driver mutation.


Assuntos
Antígeno B7-H1/antagonistas & inibidores , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Imunoterapia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/terapia , Mutação/genética , Oncogenes/genética , Animais , Antígeno B7-H1/metabolismo , Carcinoma Pulmonar de Células não Pequenas/genética , Humanos , Neoplasias Pulmonares/genética
10.
BMC Plant Biol ; 21(1): 309, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210268

RESUMO

BACKGROUND: Phytohormone abscisic acid (ABA) is involved in the regulation of a wide range of biological processes. In Arabidopsis, it has been well-known that SnRK2s are the central components of the ABA signaling pathway that control the balance between plant growth and stress response, but the functions of ZmSnRK2 in maize are rarely reported. Therefore, the study of ZmSnRK2 is of great importance to understand the ABA signaling pathways in maize. RESULTS: In this study, 14 ZmSnRK2 genes were identified in the latest version of maize genome database. Phylogenetic analysis revealed that ZmSnRK2s are divided into three subclasses based on their diversity of C-terminal domains. The exon-intron structures, phylogenetic, synteny and collinearity analysis indicated that SnRK2s, especially the subclass III of SnRK2, are evolutionally conserved in maize, rice and Arabidopsis. Subcellular localization showed that ZmSnRK2 proteins are localized in the nucleus and cytoplasm. The RNA-Seq datasets and qRT-PCR analysis showed that ZmSnRK2 genes exhibit spatial and temporal expression patterns during the growth and development of different maize tissues, and the transcript levels of some ZmSnRK2 genes in kernel are significantly induced by ABA and sucrose treatment. In addition, we found that ZmSnRK2.10, which belongs to subclass III, is highly expressed in kernel and activated by ABA. Overexpression of ZmSnRK2.10 partially rescued the ABA-insensitive phenotype of snrk2.2/2.3 double and snrk2.2/2.3/2.6 triple mutants and led to delaying plant flowering in Arabidopsis. CONCLUSION: The SnRK2 gene family exhibits a high evolutionary conservation and has expanded with whole-genome duplication events in plants. The ZmSnRK2s expanded in maize with whole-genome and segmental duplication, not tandem duplication. The expression pattern analysis of ZmSnRK2s in maize offers important information to study their functions. Study of the functions of ZmSnRK.10 in Arabidopsis suggests that the ABA-dependent members of SnRK2s are evolutionarily conserved in plants. Our study elucidated the structure and evolution of SnRK2 genes in plants and provided a basis for the functional study of ZmSnRK2s protein in maize.


Assuntos
Ácido Abscísico/metabolismo , Genes de Plantas , Transdução de Sinais , Zea mays/genética , Zea mays/metabolismo , Arabidopsis/genética , Sequência de Bases , Núcleo Celular/metabolismo , Cromossomos de Plantas/genética , Evolução Molecular , Duplicação Gênica , Regulação da Expressão Gênica de Plantas , Mutação/genética , Fenótipo , Filogenia , Transdução de Sinais/genética , Frações Subcelulares/metabolismo , Sintenia/genética
11.
BMC Plant Biol ; 21(1): 320, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217224

RESUMO

N-terminal acetylation (NTA) is a highly abundant protein modification catalyzed by N-terminal acetyltransferases (NATs) in eukaryotes. However, the plant NATs and their biological functions have been poorly explored. Here we reveal that loss of function of CKRC3 and NBC-1, the auxiliary subunit (Naa25) and catalytic subunit (Naa20) of Arabidopsis NatB, respectively, led to defects in skotomorphogenesis and triple responses of ethylene. Proteome profiling and WB test revealed that the 1-amincyclopropane-1-carboxylate oxidase (ACO, catalyzing the last step of ethylene biosynthesis pathway) activity was significantly down-regulated in natb mutants, leading to reduced endogenous ethylene content. The defective phenotypes could be fully rescued by application of exogenous ethylene, but less by its precursor ACC. The present results reveal a previously unknown regulation mechanism at the co-translational protein level for ethylene homeostasis, in which the NatB-mediated NTA of ACOs render them an intracellular stability to maintain ethylene homeostasis for normal growth and responses.


Assuntos
Aminoácido Oxirredutases/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Homeostase , Acetiltransferase N-Terminal B/metabolismo , Acetilação , Sequência de Aminoácidos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Biocatálise , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas , Morfogênese , Mutação/genética , Proteoma/metabolismo , Regulação para Cima/genética
13.
Eur Rev Med Pharmacol Sci ; 25(12): 4405-4412, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34227076

RESUMO

SARS-CoV-2 are enveloped RNA viruses that belong to the family Coronaviridae of genus Beta coronavirus, responsible for the COVID-19 pandemic. The mutation rate is high among RNA viruses and in particular, coronavirus replication is error prone with an estimated mutation rate of 4x10-4 nucleotide substitutions per site per year. Variants of SARS-CoV-2 have been reported from various countries like United Kingdom, South Africa, Denmark, Brazil and India. These variants evolved due to mutations in spike gene of SARS-CoV-2. The most concerning variants are Variant of Concern (VOC) 202012/01 from United Kingdom and B.1.617 variant of India. Other variants include B.1.351 lineages, cluster 5/SARS-CoV-2 variant of Denmark, 501.V2 variant/SARS-CoV-2 variant of South Africa, lineage B.1.1.248/lineage P.1 of Brazil. Mutations in S protein may result in changes in the transmissibility and virulence of SARS-CoV-2. To date, alterations in virulence or pathogenicity have been reported among the variants from many parts of the globe. In our opinion, since the S protein is significantly altered, the suitability of existing vaccine specifically targeting the S protein of SARS-CoV-2 variants is a major concern. The mutations in SARS-CoV-2 are a continuous and evolving process that may result in the transformation of naïve SARS-CoV-2 into totally new subsets of antigenically different SARS-CoV-2 viruses over a period of time.


Assuntos
COVID-19/epidemiologia , COVID-19/genética , Mutação/genética , SARS-CoV-2/genética , SARS-CoV-2/patogenicidade , COVID-19/transmissão , Humanos , Índia/epidemiologia , Estrutura Secundária de Proteína , SARS-CoV-2/química , Reino Unido/epidemiologia , Virulência/genética
14.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203807

RESUMO

Genome editing using CRISPR-Cas9 nucleases is based on the repair of the DNA double-strand break (DSB). In eukaryotic cells, DSBs are rejoined through homology-directed repair (HDR), non-homologous end joining (NHEJ) or microhomology-mediated end joining (MMEJ) pathways. Among these, it is thought that the NHEJ pathway is dominant and occurs throughout a cell cycle. NHEJ-based DSB repair is known to be error-prone; however, there are few studies that delve into it deeply in endogenous genes. Here, we quantify the degree of NHEJ-based DSB repair accuracy (termed NHEJ accuracy) in human-originated cells by incorporating exogenous DNA oligonucleotides. Through an analysis of joined sequences between the exogenous DNA and the endogenous target after DSBs occur, we determined that the average value of NHEJ accuracy is approximately 75% in maximum in HEK 293T cells. In a deep analysis, we found that NHEJ accuracy is sequence-dependent and the value at the DSB end proximal to a protospacer adjacent motif (PAM) is relatively lower than that at the DSB end distal to the PAM. In addition, we observed a negative correlation between the insertion mutation ratio and the degree of NHEJ accuracy. Our findings would broaden the understanding of Cas9-mediated genome editing.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Clivagem do DNA , Reparo do DNA por Junção de Extremidades/genética , Sequência de Bases , DNA/metabolismo , Células HEK293 , Células HeLa , Humanos , Mutação/genética , Oligonucleotídeos/metabolismo , RNA Guia/genética , Deleção de Sequência/genética
15.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203883

RESUMO

Variants of the TTLL5 gene, which encodes tubulin tyrosine ligase-like family member five, are a rare cause of cone dystrophy (COD) or cone-rod dystrophy (CORD). To date, only a few TTLL5 patients have been clinically and genetically described. In this study, we report five patients harbouring biallelic variants of TTLL5. Four adult patients presented either COD or CORD with onset in the late teenage years. The youngest patient had a phenotype of early onset severe retinal dystrophy (EOSRD). Genetic analysis was performed by targeted next generation sequencing of gene panels and assessment of copy number variants (CNV). We identified eight variants, of which six were novel, including two large multiexon deletions in patients with COD or CORD, while the EOSRD patient harboured the novel homozygous p.(Trp640*) variant and three distinct USH2A variants, which might explain the observed rod involvement. Our study highlights the role of TTLL5 in COD/CORD and the importance of large deletions. These findings suggest that COD or CORD patients lacking variants in known genes may harbour CNVs to be discovered in TTLL5, previously undetected by classical sequencing methods. In addition, variable phenotypes in TTLL5-associated patients might be due to the presence of additional gene defects.


Assuntos
Proteínas de Transporte/genética , Distrofias de Cones e Bastonetes/genética , Oftalmopatias Hereditárias/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Mutação/genética , Distrofias Retinianas/genética , Adulto , Idoso , Criança , Pontos de Quebra do Cromossomo , Simulação por Computador , Distrofias de Cones e Bastonetes/fisiopatologia , Variações do Número de Cópias de DNA/genética , Eletrorretinografia , Oftalmopatias Hereditárias/fisiopatologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Distrofias Retinianas/fisiopatologia
16.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34204013

RESUMO

Plant immunity is mediated in large part by specific interactions between a host resistance protein and a pathogen effector protein, named effector-triggered immunity (ETI). ETI needs to be tightly controlled both positively and negatively to enable normal plant growth because constitutively activated defense responses are detrimental to the host. In previous work, we reported that mutations in SUPPRESSOR OF rps4-RLD1 (SRFR1), identified in a suppressor screen, reactivated EDS1-dependent ETI to Pseudomonas syringae pv. tomato (Pto) DC3000. Besides, mutations in SRFR1 boosted defense responses to the generalist chewing insect Spodoptera exigua and the sugar beet cyst nematode Heterodera schachtii. Here, we show that mutations in SRFR1 enhance susceptibility to the fungal necrotrophs Fusarium oxysporum f. sp. lycopersici (FOL) and Botrytis cinerea in Arabidopsis. To translate knowledge obtained in AtSRFR1 research to crops, we generated SlSRFR1 alleles in tomato using a CRISPR/Cas9 system. Interestingly, slsrfr1 mutants increased expression of SA-pathway defense genes and enhanced resistance to Pto DC3000. In contrast, slsrfr1 mutants elevated susceptibility to FOL. Together, these data suggest that SRFR1 is functionally conserved in both Arabidopsis and tomato and functions antagonistically as a negative regulator to (hemi-) biotrophic pathogens and a positive regulator to necrotrophic pathogens.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/microbiologia , Botrytis/fisiologia , Resistência à Doença/imunologia , Fusarium/fisiologia , Imunidade Vegetal , Alelos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sequência de Bases , Sistemas CRISPR-Cas/genética , Resistência à Doença/genética , Edição de Genes , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Vetores Genéticos/metabolismo , Lycopersicon esculentum/genética , Mutação/genética , Imunidade Vegetal/genética , Plasmídeos/genética
17.
Int J Mol Sci ; 22(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34204950

RESUMO

The dysregulation of autophagy is important in the development of many cancers, including thyroid cancer, where V600EBRAF is a main oncogene. Here, we analyse the effect of V600EBRAF inhibition on autophagy, the mechanisms involved in this regulation and the role of autophagy in cell survival of thyroid cancer cells. We reveal that the inhibition of V600EBRAF activity with its specific inhibitor PLX4720 or the depletion of its expression by siRNA induces autophagy in thyroid tumour cells. We show that V600EBRAF downregulation increases LKB1-AMPK signalling and decreases mTOR activity through a MEK/ERK-dependent mechanism. Moreover, we demonstrate that PLX4720 activates ULK1 and increases autophagy through the activation of the AMPK-ULK1 pathway, but not by the inhibition of mTOR. In addition, we find that autophagy blockade decreases cell viability and sensitize thyroid cancer cells to V600EBRAF inhibition by PLX4720 treatment. Finally, we generate a thyroid xenograft model to demonstrate that autophagy inhibition synergistically enhances the anti-proliferative and pro-apoptotic effects of V600EBRAF inhibition in vivo. Collectively, we uncover a new role of AMPK in mediating the induction of cytoprotective autophagy by V600EBRAF inhibition. In addition, these data establish a rationale for designing an integrated therapy targeting V600EBRAF and the LKB1-AMPK-ULK1-autophagy axis for the treatment of V600EBRAF-positive thyroid tumours.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias da Glândula Tireoide/genética , Apoptose/efeitos dos fármacos , Autofagia/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Indóis/farmacologia , Mutação/genética , Inibidores de Proteínas Quinases/farmacologia , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/patologia
18.
Int J Mol Sci ; 22(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205075

RESUMO

Inherited neuropathies known as Charcot-Marie-Tooth (CMT) disease are genetically heterogeneous disorders affecting the peripheral nerves, causing significant and slowly progressive disability over the lifespan. The discovery of their diverse molecular genetic mechanisms over the past three decades has provided the basis for developing a wide range of therapeutics, leading to an exciting era of finding treatments for this, until now, incurable group of diseases. Many treatment approaches, including gene silencing and gene replacement therapies, as well as small molecule treatments are currently in preclinical testing while several have also reached clinical trial stage. Some of the treatment approaches are disease-specific targeted to the unique disease mechanism of each CMT form, while other therapeutics target common pathways shared by several or all CMT types. As promising treatments reach the stage of clinical translation, optimal outcome measures, novel biomarkers and appropriate trial designs are crucial in order to facilitate successful testing and validation of novel treatments for CMT patients.


Assuntos
Doença de Charcot-Marie-Tooth/terapia , Terapia Genética , Proteína P0 da Mielina/genética , Proteínas da Mielina/genética , Doença de Charcot-Marie-Tooth/genética , Inativação Gênica , Humanos , Mutação/genética , Proteína P0 da Mielina/antagonistas & inibidores , Proteínas da Mielina/antagonistas & inibidores , Nervos Periféricos/metabolismo , Nervos Periféricos/patologia
19.
BMC Plant Biol ; 21(1): 326, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34229625

RESUMO

BACKGROUND: Glycolate oxidase (GLO) is not only a key enzyme in photorespiration but also a major engine for H2O2 production in plants. Catalase (CAT)-dependent H2O2 decomposition has been previously reported to be involved in the regulation of IAA biosynthesis. However, it is still not known which mechanism contributed to the H2O2 production in IAA regulation. RESULTS: In this study, we found that in glo mutants of rice, as H2O2 levels decreased IAA contents significantly increased, whereas high CO2 abolished the difference in H2O2 and IAA contents between glo mutants and WT. Further analyses showed that tryptophan (Trp, the precursor for IAA biosynthesis in the Trp-dependent biosynthetic pathway) also accumulated due to increased tryptophan synthetase ß (TSB) activity. Moreover, expression of the genes involved in Trp-dependent IAA biosynthesis and IBA to IAA conversion were correspondingly up-regulated, further implicating that both pathways contribute to IAA biosynthesis as mediated by the GLO-dependent production of H2O2. CONCLUSION: We investigated the function of GLO in IAA signaling in different levels from transcription, enzyme activities to metabolic levels. The results suggest that GLO-dependent H2O2 signaling, essentially via photorespiration, confers regulation over IAA biosynthesis in rice plants.


Assuntos
Oxirredutases do Álcool/metabolismo , Peróxido de Hidrogênio/metabolismo , Ácidos Indolacéticos/metabolismo , Oryza/enzimologia , Oxirredutases do Álcool/genética , Vias Biossintéticas/efeitos da radiação , Respiração Celular/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Modelos Biológicos , Mutação/genética , Oryza/genética , Oryza/efeitos da radiação , Peroxissomos/metabolismo , Peroxissomos/efeitos da radiação , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Triptofano/metabolismo
20.
Anticancer Res ; 41(7): 3567-3572, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34230152

RESUMO

BACKGROUND/AIM: Medullary carcinoma (MC) of the colon is a rare subtype of colorectal adenocarcinoma (CRC) with unique histomorphology and frequent mismatch repair (MMR) deficiency. MC with exclusive squamous differentiation has not been reported. We report an unusual case of MC with squamous differentiation and tested this differentiation potential in other MMR-deficient CRC cases. CASE REPORT: A 68-year-old woman presented with a large ascending colon mass and biopsy showed squamoid tumor morphology with immunoprofile concerning for squamous cell carcinoma (SCC). She underwent right hemicolectomy. Immunohistochemistry and next-generation sequencing (NGS) were performed for tumor classification. Macroscopically, the tumor was large and locally advanced. It metastasized to the lung without lymph node metastasis. Microscopically, the tumor cells were monotonous with cytological features of both MC and SCC. Immunostains were diffusely positive for p40 and CK5/6, but negative for other lineage markers including CDX2, CK20, and SATB2. The tumor was MMR deficient with loss of MLH1 and PMS2. NGS confirmed BRAF V600E mutation. In comparison, a tissue microarray comprising 64 previously diagnosed MMR deficient CRC was tested for squamous differentiation, and only 1 case showed focal CK5/6 expression, but none was positive for p40. CONCLUSION: MC with exclusive squamous differentiation not only posed significant diagnostic challenges, but also unveiled unrecognized differentiation plasticity in this tumor type.


Assuntos
Carcinoma Medular/patologia , Carcinoma de Células Escamosas/patologia , Diferenciação Celular/fisiologia , Neoplasias do Colo/patologia , Idoso , Carcinoma Medular/genética , Carcinoma de Células Escamosas/genética , Diferenciação Celular/genética , Colo/patologia , Neoplasias do Colo/genética , Feminino , Humanos , Mutação/genética
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