RESUMO
tRNAs are short noncoding RNAs responsible for decoding mRNA codon triplets, delivering correct amino acids to the ribosome, and mediating polypeptide chain formation. Due to their key roles during translation, tRNAs have a highly conserved shape and large sets of tRNAs are present in all living organisms. Regardless of sequence variability, all tRNAs fold into a relatively rigid three-dimensional L-shaped structure. The conserved tertiary organization of canonical tRNA arises through the formation of two orthogonal helices, consisting of the acceptor and anticodon domains. Both elements fold independently to stabilize the overall structure of tRNAs through intramolecular interactions between the D- and T-arm. During tRNA maturation, different modifying enzymes posttranscriptionally attach chemical groups to specific nucleotides, which not only affect translation elongation rates but also restrict local folding processes and confer local flexibility when required. The characteristic structural features of tRNAs are also employed by various maturation factors and modification enzymes to assure the selection, recognition, and positioning of specific sites within the substrate tRNAs. The cellular functional repertoire of tRNAs continues to extend well beyond their role in translation, partly, due to the expanding pool of tRNA-derived fragments. Here, we aim to summarize the most recent developments in the field to understand how three-dimensional structure affects the canonical and noncanonical functions of tRNA.
Assuntos
Anticódon , RNA de Transferência , Conformação de Ácido Nucleico , RNA de Transferência/genética , RNA de Transferência/metabolismo , Anticódon/metabolismo , Biossíntese de Proteínas , Ribossomos/metabolismoRESUMO
Endosymbiosis has driven major molecular and cellular innovations. Plasmodium spp. parasites that cause malaria contain an essential, non-photosynthetic plastid-the apicoplast-which originated from a secondary (eukaryote-eukaryote) endosymbiosis. To discover organellar pathways with evolutionary and biomedical significance, we performed a mutagenesis screen for essential genes required for apicoplast biogenesis in Plasmodium falciparum. Apicoplast(-) mutants were isolated using a chemical rescue that permits conditional disruption of the apicoplast and a new fluorescent reporter for organelle loss. Five candidate genes were validated (out of 12 identified), including a triosephosphate isomerase (TIM)-barrel protein that likely derived from a core metabolic enzyme but evolved a new activity. Our results demonstrate, to our knowledge, the first forward genetic screen to assign essential cellular functions to unannotated P. falciparum genes. A putative TIM-barrel enzyme and other newly identified apicoplast biogenesis proteins open opportunities to discover new mechanisms of organelle biogenesis, molecular evolution underlying eukaryotic diversity, and drug targets against multiple parasitic diseases.
Assuntos
Apicoplastos/genética , Genes Essenciais , Mutação , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Triose-Fosfato Isomerase/genética , Apicoplastos/metabolismo , Sistemas CRISPR-Cas , Eritrócitos/parasitologia , Ontologia Genética , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Metaloproteases/genética , Metaloproteases/metabolismo , Anotação de Sequência Molecular , Mutagênese , Biogênese de Organelas , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Triose-Fosfato Isomerase/metabolismo , Sequenciamento Completo do Genoma , Proteína Vermelha FluorescenteRESUMO
Celiac disease (CD) is widely perceived as a childhood disorder. However, it has been demonstrated that 19-34% of new CD cases are diagnosed in patients over 60 years of age and lack the typical presentation. A 76-year-old female was admitted to the clinic due to a recurrent fever that had lasted over a year accompanied by progressive weakness, weight loss of about 10 kg, dehydration, and malnutrition. The patient had undergone resection of a fragment of the small intestine due to perforation and abscess 13 years previously (at which time no histopathological examinations were performed). During the current hospitalization, despite extensive laboratory, microbiological, and imaging tests, no specific diagnosis was made. Symptomatic treatment and empirical antibiotic therapy were conducted, but the patient died on the twenty-seventh day of hospitalization due to progressive respiratory failure. The autopsy revealed peripheral T-cell lymphoma in the mesentery of the small intestine, uterus, cecum, lung, and mediastinal lymph nodes. Based on the clinical picture, we believe that the lymphoma was induced by long-term, undiagnosed CD. Current knowledge allows us to see age-related differences in the manifestation of celiac disease and to be alert to the possible late-stage complications of the disease. The lack of awareness of how CD's symptoms vary with age may lead to misdiagnosis and serious consequences of delayed diagnosis, including death.
Assuntos
Doença Celíaca , Linfoma de Células T Periférico , Idoso , Doença Celíaca/complicações , Doença Celíaca/diagnóstico , Criança , Testes Diagnósticos de Rotina , Feminino , Humanos , Intestino Delgado , Linfoma de Células T Periférico/complicações , Linfoma de Células T Periférico/diagnóstico , Pessoa de Meia-Idade , Redução de PesoRESUMO
The reprogramming of human induced pluripotent stem cells (hiPSCs) proceeds in a stepwise manner with reprogramming factors binding and epigenetic composition changes during transition to maintain the epigenetic landscape, important for pluripotency. There arises a question as to whether the aberrant epigenetic state after reprogramming leads to epigenetic defects in induced stem cells causing unpredictable long term effects in differentiated cells. In this review, we present a comprehensive view of epigenetic alterations accompanying reprogramming, cell maintenance and differentiation as factors that influence applications of hiPSCs in stem cell based technologies. We conclude that sample heterogeneity masks DNA methylation signatures in subpopulations of cells and thus believe that beside a genetic evaluation, extensive epigenomic screening should become a standard procedure to ensure hiPSCs state before they are used for genome editing and differentiation into neurons of interest. In particular, we suggest that exploitation of the single-cell composition of the epigenome will provide important insights into heterogeneity within hiPSCs subpopulations to fast forward development of reliable hiPSC-based analytical platforms in neurological disorders modelling and before completed hiPSC technology will be implemented in clinical approaches.
Assuntos
Reprogramação Celular/genética , Reprogramação Celular/fisiologia , Epigênese Genética , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/fisiopatologia , Animais , Epigenômica , Humanos , Células-Tronco Pluripotentes/fisiologiaRESUMO
Genetic diseases occur in breeds used for law enforcement. As important team members, dogs are expected to operate at peak performance for several years and are significant investments for both the initial purchase and extensive, specialized training. Previous studies have not focused on causes for retirement or euthanasia as genetic (inherited) versus acquired (environmental). We performed direct mutational analysis for breed-specific conditions on samples from 304 dogs including 267 law enforcement (122 US, 87 Israeli, and 58 Polish) and 37 search and rescue dogs. Genetic testing identified 29% (n = 89) of the dogs tested to be carriers of a genetic mutation and 6% (n = 19) to be at risk for a debilitating inherited condition that may eventually impair the dog's ability to work. At-risk dogs included Labrador Retrievers (n = 4) with exercise-induced collapse, Bloodhounds (n = 2) with degenerative myelopathy (DM), and German Shepherd dogs with DM (n = 12) or leukocyte adhesion deficiency, type III (n = 1). A substantial number of working dogs were shown to be at risk for genetic conditions that may shorten the dog's career. The loss of dogs, due to early retirement or euthanasia, as a result of preventable genetic conditions has an emotional cost to handlers and financial cost to service organizations that can be avoided with genetic screening prior to breeding, buying, or training.
Assuntos
Doenças do Cão/epidemiologia , Cães/genética , Doenças Genéticas Inatas/veterinária , Animais , Cruzamento , Doenças do Cão/genética , Triagem de Portadores Genéticos , Doenças Genéticas Inatas/epidemiologia , Doenças Genéticas Inatas/genética , Predisposição Genética para Doença , Genótipo , Inquéritos Epidemiológicos , Israel/epidemiologia , Polônia/epidemiologia , Especificidade da Espécie , Estados Unidos/epidemiologiaRESUMO
Autophagy is a conserved process for the bulk degradation of cytoplasmic material. Triggering of autophagy results in the formation of double membrane-bound vesicles termed autophagosomes. The conserved Atg5-Atg12/Atg16 complex is essential for autophagosome formation. Here, we show that the yeast Atg5-Atg12/Atg16 complex directly binds membranes. Membrane binding is mediated by Atg5, inhibited by Atg12 and activated by Atg16. In a fully reconstituted system using giant unilamellar vesicles and recombinant proteins, we reveal that all components of the complex are required for efficient promotion of Atg8 conjugation to phosphatidylethanolamine and are able to assign precise functions to all of its components during this process. In addition, we report that in vitro the Atg5-Atg12/Atg16 complex is able to tether membranes independently of Atg8. Furthermore, we show that membrane binding by Atg5 is downstream of its recruitment to the pre-autophagosomal structure but is essential for autophagy and cytoplasm-to-vacuole transport at a stage preceding Atg8 conjugation and vesicle closure. Our findings provide important insights into the mechanism of action of the Atg5-Atg12/Atg16 complex during autophagosome formation.
Assuntos
Autofagia , Proteínas de Transporte/metabolismo , Fagossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteína 12 Relacionada à Autofagia , Proteína 5 Relacionada à Autofagia , Família da Proteína 8 Relacionada à Autofagia , Proteínas Relacionadas à Autofagia , Transporte Biológico/fisiologia , Membrana Celular/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Fosfatidiletanolaminas/metabolismo , Ubiquitina-Proteína LigasesRESUMO
Cystinuria is a purely renal, rare genetic disease caused by mutations in cystine transporter genes and characterized by defective cystine reabsorption leading to kidney stones. In 14% of cases, patients undergo nephrectomy, but given the difficulty to predict the evolution of the disease, the identification of markers of kidney damage would improve the follow-up of patients with a higher risk. The aim of the present study is to develop a robust, reproducible, and noninvasive methodology for proteomic analysis of urinary exosomes using high resolution mass spectrometry. A clinical pilot study conducted on eight cystinuria patients versus 10 controls highlighted 165 proteins, of which 38 were up-regulated, that separate cystinuria patients from controls and further discriminate between severe and moderate forms of the disease. These proteins include markers of kidney injury, circulating proteins, and a neutrophil signature. Analysis of selected proteins by immunobloting, performed on six additional cystinuria patients, validated the mass spectrometry data. To our knowledge, this is the first successful proteomic study in cystinuria unmasking the potential role of inflammation in this disease. The workflow we have developed is applicable to investigate urinary exosomes in different renal diseases and to search for diagnostic/prognostic markers. Data are available via ProteomeXchange with identifier PXD001430.
Assuntos
Biomarcadores/metabolismo , Cistinúria/metabolismo , Exossomos/metabolismo , Regulação da Expressão Gênica/genética , Proteômica/métodos , Cromatografia Líquida de Alta Pressão , Biologia Computacional , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Immunoblotting , Focalização Isoelétrica , Masculino , Microscopia Imunoeletrônica , Projetos Piloto , Coloração pela Prata , Espectrometria de Massas em Tandem/métodosRESUMO
BACKGROUND: Statins are the first-line treatment for dyslipidemia, which is a major modifiable risk factor for atherosclerotic cardiovascular disease. Studies have shown that in addition to the beneficial lipid-lowering effect, statins also exhibit a number of pleiotropic effects that may find application in other diseases, including osteoporosis. This study aimed to assess the effect of statins on bone turnover, as measured by the concentration of bone turnover markers, and to compare the effect of atorvastatin as a lipophilic statin and rosuvastatin as a hydrophilic statin. METHODS: This study included 34 postmenopausal women agedâ <â 65 years with newly diagnosed dyslipidemia requiring statin therapy. Patients were randomly assigned to receive a statin drug. Statins were initiated at standard doses of 5 to 10 mg of rosuvastatin and 20 mg of atorvastatin. The levels of C-terminal telopeptide of type I collagen as a bone resorption marker and N-terminal propeptide of procollagen type I as a marker of bone formation, lipid concentrations and other biochemical parameters were assessed at baseline and after 6 and twelve months of treatment. RESULTS: There were no statistically significant differences between the levels of bone turnover markers before and 6 months after statin implementation (Pâ >â .05) - for all patients or subgroups according to statin use. Analysis of the results showed that after 12 months, there was a statistically significant decrease in N-terminal propeptide of procollagen type I concentration in all subjects (Pâ =â .004). By statin subgroup, a statistically significant decrease in N-terminal propeptide of procollagen type I was observed only in patients receiving rosuvastatin (Pâ =â .012) and not in those receiving atorvastatin (Pâ =â .25). Moreover, changes in bone turnover markers did not correlate with changes in lipid concentrations. CONCLUSIONS: These results may indicate the superiority of atorvastatin over rosuvastatin in inhibiting adverse changes in bone turnover in postmenopausal women. Confirmed by studies involving a larger population, the observed differences might find particular applications in clinical practice, and the choice of atorvastatin over rosuvastatin for women could be considered in the early postmenopausal period to reduce the risk of osteoporosis and subsequent osteoporotic fractures.
Assuntos
Atorvastatina , Remodelação Óssea , Inibidores de Hidroximetilglutaril-CoA Redutases , Pós-Menopausa , Rosuvastatina Cálcica , Humanos , Rosuvastatina Cálcica/uso terapêutico , Rosuvastatina Cálcica/administração & dosagem , Feminino , Atorvastatina/uso terapêutico , Atorvastatina/farmacologia , Pessoa de Meia-Idade , Remodelação Óssea/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Biomarcadores/sangue , Colágeno Tipo I/sangue , Osteoporose Pós-Menopausa/tratamento farmacológico , Dislipidemias/tratamento farmacológico , Dislipidemias/sangueRESUMO
Genetic mechanisms of blood pressure (BP) regulation remain poorly defined. Using kidney-specific epigenomic annotations and 3D genome information we generated and validated gene expression prediction models for the purpose of transcriptome-wide association studies in 700 human kidneys. We identified 889 kidney genes associated with BP of which 399 were prioritised as contributors to BP regulation. Imputation of kidney proteome and microRNAome uncovered 97 renal proteins and 11 miRNAs associated with BP. Integration with plasma proteomics and metabolomics illuminated circulating levels of myo-inositol, 4-guanidinobutanoate and angiotensinogen as downstream effectors of several kidney BP genes (SLC5A11, AGMAT, AGT, respectively). We showed that genetically determined reduction in renal expression may mimic the effects of rare loss-of-function variants on kidney mRNA/protein and lead to an increase in BP (e.g., ENPEP). We demonstrated a strong correlation (r = 0.81) in expression of protein-coding genes between cells harvested from urine and the kidney highlighting a diagnostic potential of urinary cell transcriptomics. We uncovered adenylyl cyclase activators as a repurposing opportunity for hypertension and illustrated examples of BP-elevating effects of anticancer drugs (e.g. tubulin polymerisation inhibitors). Collectively, our studies provide new biological insights into genetic regulation of BP with potential to drive clinical translation in hypertension.
Assuntos
Hipertensão , Proteoma , Humanos , Pressão Sanguínea/genética , Proteoma/genética , Proteoma/metabolismo , Transcriptoma/genética , Multiômica , Hipertensão/metabolismo , Rim/metabolismo , Proteínas de Transporte de Sódio-Glucose/genética , Proteínas de Transporte de Sódio-Glucose/metabolismoRESUMO
Metabolic-associated fatty liver disease (MAFLD), previously known as non-alcoholic fatty liver disease, is a significant epidemiological problem and a well-known cardiovascular risk factor. The increasing number of cases creates the need for new therapeutic methods aimed at improving patient outcomes. Recent studies have highlighted the relationship between MAFLD and proprotein convertase subtilisin/kexin type 9 (PCSK9). Based on the available data, PCSK9 inhibitors appear to have beneficial effects in patients with MAFLD, and they may be a treatment option in the future. Further research is necessary to better evaluate the efficiency of PCSK9 inhibitors in MAFLD treatment.
RESUMO
Atg8 family proteins are highly conserved eukaryotic proteins with diverse autophagy and nonautophagic functions in eukaryotes. While the structural features required for conserved autophagy functions of Atg8 are well established, little is known about the molecular changes that facilitated acquisition of divergent, nonautophagic functions of Atg8. The malaria parasite Plasmodium falciparum offers a unique opportunity to study nonautophagic functions of Atg8 family proteins because it encodes a single Atg8 homolog whose only essential function is in the inheritance of an unusual secondary plastid called the apicoplast. Here, we used functional complementation to investigate the structure-function relationship for this divergent Atg8 protein. We showed that the LC3-interacting region (LIR) docking site (LDS), the major interaction interface of the Atg8 protein family, is required for P. falciparum Atg8 (PfAtg8) apicoplast localization and function, likely via Atg8 lipidation. On the other hand, another region previously implicated in canonical Atg8 interactions, the N-terminal helix, is not required for apicoplast-specific PfAtg8 function. Finally, our investigations at the cellular level demonstrate that the unique apicomplexan-specific loop, previously implicated in interaction with membrane conjugation machinery in recombinant protein-based in vitro assays, is not required for membrane conjugation nor for the apicoplast-specific effector function of Atg8 in both P. falciparum and related Apicomplexa member Toxoplasma gondii. These results suggest that the effector function of apicomplexan Atg8 is mediated by structural features distinct from those previously identified for macroautophagy and selective autophagy functions. IMPORTANCE The most extensively studied role of Atg8 proteins is in autophagy. However, it is clear that they have other nonautophagic functions critical to cell function and disease pathogenesis that are so far understudied compared to their canonical role in autophagy. Mammalian cells contain multiple Atg8 paralogs that have diverse, specialized functions. Gaining molecular insight into their nonautophagic functions is difficult because of redundancy between the homologs and their role in both autophagy and nonautophagic pathways. Malaria parasites such as Plasmodium falciparum are a unique system to study a novel, nonautophagic function of Atg8 separate from its role in autophagy: they have only one Atg8 protein whose only essential function is in the inheritance of the apicoplast, a unique secondary plastid organelle. Insights into the molecular basis of PfAtg8's function in apicoplast biogenesis will have important implications for the evolution of diverse nonautophagic functions of the Atg8 protein family.
Assuntos
Apicoplastos , Malária , Parasitos , Animais , Apicoplastos/metabolismo , Família da Proteína 8 Relacionada à Autofagia/genética , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Malária/metabolismo , Mamíferos/metabolismo , Parasitos/metabolismo , Proteínas de Protozoários/metabolismo , Relação Estrutura-AtividadeRESUMO
In this work, a chromatographic method for identification of volatile organic compounds was compared with canine recognition. Gas chromatography and mass spectrometry (GC-TOF MS) were used for determination of concentrations of trace gases present in human breath. The technique enables rapid determination of compounds in human breath, at the parts per billion level. Linear correlations were from 0.83-234.05 ppb, the limit of detection was the range 0.31-0.75 ppb, and precision, expressed as relative standard deviation (RSD), was less than 10.00 %. Moreover, trained dogs are able to discriminate breath samples of patients with diagnosed cancer. We found a positive correlation between dog indications and the ethyl acetate and 2-pentanone content of breath (r = 0.85 and r = 0.97, respectively). The methods presented for detection of lung cancer markers in exhaled air could be used as a potential non-invasive tool for screening. In addition, the canine method is relatively simple and inexpensive in comparison with chromatography.
Assuntos
Biomarcadores Tumorais/química , Testes Respiratórios/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Neoplasias Pulmonares/diagnóstico , Compostos Orgânicos Voláteis/química , Animais , Cães , Feminino , Humanos , Masculino , Especificidade da EspécieRESUMO
Background: Resistin action links to conditions such as diabetes, obesity, but its role in hypertension is less well understood. This study aimed to estimate the relationship between resistin (-420G/C) single nucleotide variant (SNV) and markers associated with endothelial dysfunction in hypertension. Methods: The study enrolled 162 hypertensive patients (HT) and 165 non-hypertensive (NHT) patients. Resistin serum concentration was estimated with immuoenzymatic assay. Anthropometric measurements, blood pressure and arterial stiffness index (SI), uric acid (UA) serum concentration, and salty taste preference of normal (NS) or high (HS) were assessed in the study. Genotyping was achieved by polymerase chain reaction-restriction fragment length polymorphism. Results: Resistin concentration and SI do not differ significantly between HT and NHT individuals; UA significantly increased in HT subjects. Resistin, UA, and SI did not differ among particular resistin genotypes in HT, NHT, NS, or HS groups. GG and CG genotypes were more frequent (OR 1.57 (95% CI; 1.01-2.43); p = 0.04) in hypertensive individuals than the NHT group, but less frequent (OR 0.58 (95% CI; 0.37-0.91); p = 0.01) in HS patients compared to NS individuals. Concerning HT patients with different salt preferences, GG + CG genotypes were less frequent (OR 0.50 (95% CI; 0.26-0.97); p = 0.04) in the HS group than in NS individuals. HT carriers of GG and CG genotype have significantly increased UA concentrations compared to the respective NHT subjects. HS individuals carrying GG and CG genotypes have higher SI values than the NS group. Allele G of SNV (-420G/C) adjusted for age, BMI, serum resistin, UA concentration, salt taste preference, SI, and HR values increased the risk of developing hypertensive phenotype 1.8 fold. Conclusions: Resistin SNV (-420G/C) is related to several markers associated with endothelial dysfunction, including salt taste preference in hypertensive patients.
Assuntos
Hipertensão , Resistina , Biomarcadores , Predisposição Genética para Doença , Genótipo , Humanos , Hipertensão/genética , Nucleotídeos , Polimorfismo de Nucleotídeo Único , Resistina/genética , Paladar/genéticaRESUMO
Colorectal cancer (CRC) is the third most common malignancy. Its development and progression is associated with natural immunosuppression related, among others, to myeloid derived suppressor cells (MDSCs). Overall, 54 patients in different stage of CRC, before any treatment were recruited into the study. The analysis included flow cytometry evaluation of blood MDSCs subsets, correlation their level with the tumor stage and T cell subsets. In the case of 11 patients, MDSCs level was evaluated before and 3 days after surgery, and these patients were monitored for cancer recurrence over 5 years. The results showed that frequency of circulating MDSCs subsets is increased significantly in CRC patients, with highest level detected in most advanced tumor stages. Moreover, only monocytic MDSCs (Mo-MDSCs) positively correlate with regulatory Treg, and negatively with tumor Her2/neu specific CD8+ T cells. Circulating MDSCs, in contrast to tumor resident (mostly Mo-MDSCs), are negative for PD-L1 expression. Additionally, after surgery the blood level of Mo-MDSCs increases significantly, and this is associated with tumor recurrence during a 5-year follow-up. In conclusion, Mo-MDSCs are pivotal players in CRC-related immunosuppression and may be associated with the risk of tumor recurrence after surgery.
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The outstanding sensitivity of the canine olfactory system has been acknowledged by using sniffer dogs in military and civilian service for detection of a variety of odors. It is hypothesized that the canine olfactory ability is determined by polymorphisms in olfactory receptor (OR) genes. We investigated 5 OR genes for polymorphic sites which might affect the olfactory ability of service dogs in different fields of specific substance detection. All investigated OR DNA sequences proved to have allelic variants, the majority of which lead to protein sequence alteration. Homozygous individuals at 2 gene loci significantly differed in their detection skills from other genotypes. This suggests a role of specific alleles in odor detection and a linkage between single-nucleotide polymorphism and odor recognition efficiency.
Assuntos
Cães/genética , Receptores Odorantes/genética , Olfato/genética , Adenina , Alelos , Animais , Análise Mutacional de DNA , Cães/fisiologia , Substâncias Explosivas/análise , Guanina , Humanos , Masculino , Neoplasias/diagnóstico , Polícia , Polimorfismo de Fragmento de Restrição , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Plasmodium parasites and related pathogens contain an essential nonphotosynthetic plastid organelle, the apicoplast, derived from secondary endosymbiosis. Intriguingly, a highly conserved eukaryotic protein, autophagy-related protein 8 (ATG8), has an autophagy-independent function in the apicoplast. Little is known about the novel apicoplast function of ATG8 and its importance in blood-stage Plasmodium falciparum Using a P. falciparum strain in which ATG8 expression was conditionally regulated, we showed that P. falciparum ATG8 (PfATG8) is essential for parasite replication. Significantly, growth inhibition caused by the loss of PfATG8 was reversed by addition of isopentenyl pyrophosphate (IPP), which was previously shown to rescue apicoplast defects in P. falciparum Parasites deficient in PfATG8, but whose growth was rescued by IPP, had lost their apicoplast. We designed a suite of functional assays, including a new fluorescence in situ hybridization (FISH) method for detection of the low-copy-number apicoplast genome, to interrogate specific steps in apicoplast biogenesis and detect apicoplast defects which preceded the block in parasite replication. Though protein import and membrane expansion of the apicoplast were unaffected, the apicoplast was not inherited by daughter parasites. Our findings demonstrate that, though multiple autophagy-dependent and independent functions have been proposed for PfATG8, only its role in apicoplast biogenesis is essential in blood-stage parasites. We propose that PfATG8 is required for fission or segregation of the apicoplast during parasite replication.IMPORTANCEPlasmodium parasites, which cause malaria, and related apicomplexan parasites are important human and veterinary pathogens. They are evolutionarily distant from traditional model organisms and possess a unique plastid organelle, the apicoplast, acquired by an unusual eukaryote-eukaryote endosymbiosis which established novel protein/lipid import and organelle inheritance pathways in the parasite cell. Though the apicoplast is essential for parasite survival in all stages of its life cycle, little is known about these novel biogenesis pathways. We show that malaria parasites have adapted a highly conserved protein required for macroautophagy in yeast and mammals to function specifically in apicoplast inheritance. Our finding elucidates a novel mechanism of organelle biogenesis, essential for pathogenesis, in this divergent branch of pathogenic eukaryotes.
Assuntos
Apicoplastos/metabolismo , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Biogênese de Organelas , Plasmodium falciparum/fisiologia , Proteínas de Protozoários/metabolismo , Família da Proteína 8 Relacionada à Autofagia/genética , Eritrócitos/parasitologia , Deleção de Genes , Hemiterpenos/metabolismo , Humanos , Compostos Organofosforados/metabolismo , Plasmodium falciparum/genética , Plasmodium falciparum/crescimento & desenvolvimento , Proteínas de Protozoários/genéticaAssuntos
Síndrome de Cushing , Lipodistrofia , Lipomatose Simétrica Múltipla , Lipomatose , Humanos , GTP Fosfo-Hidrolases , Lipomatose/complicações , Lipomatose/diagnóstico por imagem , Lipomatose Simétrica Múltipla/diagnóstico , Lipomatose Simétrica Múltipla/diagnóstico por imagem , Proteínas Mitocondriais , Feminino , AdultoRESUMO
Disorders of voice breaking in adolescent boys (mutational dysphonia) could be a result of local, hormonal, neuropsychiatric or sensual factors. The aim of this paper was the voice assessment of three subjects with incomplete mutation with particular additional factors, disturbing hearing, voice and speech: like hearing loss, hyperfunctional childhood dysphonia and speech dysfluency. Diagnostics included complete phoniatric examination with perceptive estimation, videostroboscopy and acoustic voice analysis, done before and after treatment. Rehabilitation process results were well seen in perceptive and objective voice analysis except significant improvement of fundamental frequency average. Analysis of incomplete mutation etiological factors need special attention due to coexist with another voice, speech and hearing disorders, which undergo with high tension of voice organ muscles or with the lack of phonation auditory feedback.
Assuntos
Puberdade , Gagueira/diagnóstico , Gagueira/terapia , Distúrbios da Voz/diagnóstico , Distúrbios da Voz/terapia , Treinamento da Voz , Adolescente , Humanos , Masculino , Resultado do Tratamento , Qualidade da VozRESUMO
UNLABELLED: The aim of the study was to determine the parents view and attitude to the universal neonatal hearing screening. MATERIAL AND METHODS: parents of randomly selected 200 infants, who underwent hearing rescreening, were surveyed using the authors questionnaire. RESULTS: the universal neonatal hearing screening and the way it is conducted is accepted by the vast majority of the parents in the region of Wielkopolska. The parents with higher social and economic status express their negative emotions associated with the organisation of hearing screening more often, their expectations towards the system of medical care are rising. CONCLUSION: the newborn hearing screening has been a good stimulus for parents intently observation of their child auditory reaction.