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AIM: To investigate the DNA damage response (DDR) in a cyclophosphamide (CTX)-induced mouse model of premature ovarian failure (POF). METHODS: The POF model was established by injecting mice with CTX. The body, ovarian weights, the estrus cycle, and pathological changes of the ovaries were recorded. The serum levels of 17 ß-estradiol (E2) and follicle-stimulating hormone (FSH) were measured. The expression of Ki67, ß-galactosidase (ß-gal), p21, p53, γH2AX, and pATM in ovarian tissues was detected by immunohistochemistry. The expression of ß-gal, γH2AX, and pATM was analyzed by immunofluorescence staining of primary cultured granulosa cells (GCs). RESULTS: The body and ovarian weights decreased, the estrus cycles were erratic, and the FSH level increased, whereas the E2 level decreased in POF mice compared to controls. The pathological consequences of POF revealed an increase in atretic follicles, corpus luteum, and primordial follicles and a decrease in the number of primary, secondary, and tertiary follicles. Ki67 expression was reduced, ß-gal, p21, p53, γH2AX, and pATM expression were elevated in the ovaries of POF mice. The expression of ß-gal, γH2AX, and pATM increased in GCs with the concentration in a time-dependent manner. CONCLUSION: In total, CTX induced POF in mice, which was mediated by the DDR pathway of ATM-P53-P21.
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Esomeprazole is the most popular proton pump inhibitor for treating gastroesophageal reflux disease. Previously, a phenylacetone monooxygenase mutant LnPAMOmu15 (LM15) was obtained by protein engineering for asymmetric synthesis of esomeprazole using pyrmetazole as substrate. To scale up the whole cell asymmetric synthesis of esomeprazole and reduce the cost, in this work, an Escherichia coli whole-cell catalyst harboring LM15 and formate dehydrogenase from Burkholderia stabilis 15516 (BstFDH) were constructed through optimized gene assembly patterns. CRISPR/Cas9 mediated insertion of Ptrc promoter in genome was done to enhance the expression of key genes to increase the cellular NADP supply in the whole cell catalyst, by which the amount of externally added NADP+ for the asymmetric synthesis of esomeprazole decreased to 0.05â¯mM from 0.3â¯mM for reducing the cost. After the optimization of reaction conditions in the reactor, the scalable synthesis of esomeprazole was performed using the efficient LM15-BstFDH whole-cell as catalyst, which showed the highest reported space-time yield of 3.28â¯g/L/h with 50â¯mM of pyrmetazole loading. Isolation procedure was conducted to obtain esomeprazole sodium of 99.55â¯% purity and >â¯99.9â¯% ee with 90.1â¯% isolation yield. This work provides the basis for production of enantio-pure esomeprazole via cost-effective whole cell biocatalysis.
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Biocatálise , Burkholderia , Escherichia coli , Esomeprazol , Esomeprazol/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Burkholderia/genética , Burkholderia/enzimologia , Burkholderia/metabolismo , Coenzimas/metabolismo , Vias Biossintéticas , Engenharia Metabólica , Formiato Desidrogenases/metabolismo , Formiato Desidrogenases/genética , Sistemas CRISPR-Cas , Oxigenases de Função Mista/metabolismo , Oxigenases de Função Mista/genéticaRESUMO
Ovarian cancer is a multifactorial and deadly disease. Despite significant advancements in ovarian cancer therapy, its incidence is on the rise and the molecular mechanisms underlying ovarian cancer invasiveness, metastasis and drug resistance remain largely elusive, resulting in poor prognosis. Oncolytic viruses armed with therapeutic transgenes of interest offer an attractive alternative to chemical drugs, which often face innate and acquired drug resistance. The present study constructed a novel oncolytic adenovirus carrying ERCC1 short interfering (si)RNA, regulated by hTERT and HIF promoters, termed AdsiERCC1. The findings demonstrated that this oncolytic adenovirus effectively inhibits the proliferation, migration and invasion of ovarian cancer cells. Furthermore, the downregulation of ERCC1 expression by siRNA ameliorates drug resistance to cisplatin (DDP) chemotherapy. It was found that AdsiERCC1 blocks the cell cycle in the G1 phase and enhances apoptosis through the PI3K/AKTcaspase3 signaling pathways in SKOV3 cells. The results of the present study highlighted the critical effect of oncolytic virus AdsiERCC1 in inhibiting the survival of ovarian cancer cells and increasing chemotherapy sensitivity to DDP. These findings underscore the potent antitumor effect of AdsiERCC1 on ovarian cancers in vivo.
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Adenoviridae , Proteínas de Ligação a DNA , Endonucleases , Vírus Oncolíticos , Neoplasias Ovarianas , RNA Interferente Pequeno , Feminino , Humanos , Adenoviridae/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Endonucleases/genética , Endonucleases/metabolismo , Vetores Genéticos/genética , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/genética , Neoplasias Ovarianas/terapia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de SinaisRESUMO
Background: Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD) account for the vast majority of neurodegenerative dementias. AD and FTLD have different clinical phenotypes with a genetic overlap between them and other dementias. Objective: This study aimed to identify the genetic spectrum of sporadic AD and FTLD in the Chinese population. Methods: A total of 74 sporadic AD and 29 sporadic FTLD participants were recruited. All participants underwent whole-exome sequencing (WES) and testing for a hexanucleotide expansion in C9orf72 was additionally performed for participants with negative WES results. Results: Four known pathogenic or likely pathogenic variants, including PSEN1 (p.G206D), MAPT (p.R5H), LRRK2 (p.W1434*), and CFAP43 (p.C934*), were identified in AD participants, and 1 novel pathogenic variant of ANXA11 (p.D40G) and two known likely pathogenic variants of MAPT (p.D177V) and TARDBP (p.I383V) were identified in FTLD participants. Twenty-four variants of uncertain significance as well as rare variants in risk genes for dementia, such as ABCA7, SORL1, TRPM7, NOS3, MPO, and DCTN1, were also found. Interestingly, several variants in participants with semantic variant primary progressive aphasia were detected. However, no participants with C9orf72 gene variants were found in the FTLD cohort. Conclusions: There was a high frequency of genetic variants in Chinese participants with sporadic AD and FTLD and a complex genetic overlap between these two types of dementia and other neurodegenerative diseases.
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Doença de Alzheimer , Povo Asiático , Degeneração Lobar Frontotemporal , Testes Genéticos , Humanos , Masculino , Feminino , Doença de Alzheimer/genética , Degeneração Lobar Frontotemporal/genética , Idoso , Testes Genéticos/métodos , Povo Asiático/genética , Pessoa de Meia-Idade , Sequenciamento do Exoma , China/epidemiologia , Proteína C9orf72/genética , Idoso de 80 Anos ou mais , Predisposição Genética para Doença/genética , População do Leste AsiáticoRESUMO
We describe the phylogenetic analysis and expression pattern of the Xenopus radial spoke protein 3 (RSP3) gene during early development. The Xenopus RSP3 protein presents characteristic features of the RSP3 family. It contains a radial spoke domain, which is 75 and 72 % identical to the corresponding region of human and Chlamydomonas RSP3 proteins, respectively. Examination of the phylogenetic relationship between the Xenopus RSP3 protein and its known homologues from different deuterostomes indicates that the RSP3 proteins are highly conserved among deuterostomes. Whole-mount in situ hybridization analyses show that Xenopus RSP3 is a maternal mRNA enriched in the animal hemisphere during cleavage stages. The expression is detected in the dorsal region of the embryo during gastrulation, then in the presumptive neuroectoderm at the end of gastrulation. During neurulation and at the subsequent stages, the expression of RSP3 mRNA is detected in the entire multiciliated cells of epidermis. At tail-bud stages, it is progressively expressed in the otic vesicles and sequentially expressed in the nephrostomes. Expression could be also detected in the floor plate of the neural tube. This expression pattern persists until at least late tail-bud stages.
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Orelha , Epiderme/metabolismo , Rim/metabolismo , Proteínas de Xenopus/genética , Sequência de Aminoácidos , Animais , Células Epidérmicas , Rim/citologia , Dados de Sequência Molecular , Filogenia , Homologia de Sequência de Aminoácidos , Xenopus , Proteínas de Xenopus/químicaRESUMO
Glucocorticoids, which are a class of steroidal hormones secreted by the adrenal cortex, have significant anti-inflammatory, immunosuppressive, and anti-allergic effects. Thus, these compounds are widely used in clinical practice. However, the long-term use of cosmetics containing glucocorticoids can lead to serious consequences, such as hormone-dependent dermatitis, hypertension, and other serious injuries. The Safety and Technical Specification for Cosmetics (2015 edition) and Regulation (EC) No. 1223/2009 of the European Parliament and Council on cosmetic products list glucocorticoids as prohibited raw materials. According to the National Medical Products Administration, reports on the illegal addition of glucocorticoids to cosmetics by manufacturers have increased in recent years. Therefore, establishing high-throughput screening methods to ensure the quality and safety of cosmetics is imperative. In this study, a comprehensive analytical method based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the rapid screening of 83 glucocorticoids in cosmetics. A series of conditions were optimized using three matrices that are commonly used in cosmetics: water, lotion, and cream (o/w-type). Four mobile-phase systems and three chromatographic columns were then optimized to achieve the best separation effects. Various MS parameters, such as the capillary voltages, cone voltages, desolvation gas flow rates, and collision energies of the ion pairs of the target compounds, were also optimized. Furthermore, pretreatment was essential for glucocorticoid determination owing to the complex matrix effects of cosmetics. The analytes were divided into two groups, with lg Kow=4 as the limit, to compare the effects of the extraction solvent on recoveries. The extraction recoveries of target analytes with six extraction methods, namely, extraction with acetonitrile, extraction with acetone, extraction with ethyl acetate, dispersion in saturated sodium chloride solution followed by extraction with acetonitrile, dispersion in saturated sodium chloride solution followed by extraction with acetone, and dispersion in saturated sodium chloride solution followed by extraction with ethyl acetate, were compared. The recoveries from QuEChERS and solid-phase extraction (SPE) purification were also compared. Based on the experimental results, the final sample pretreatment method included acetonitrile vortex dispersion, ultrasonic extraction, and sample loading after filtration. The 83 target compounds were separated on a Thermo Accucore PFP column (100 mm×2.1 mm, 2.6 µm) with 0.1% (v/v) acetic acid in acetonitrile and 0.1% (v/v) acetic acid in water as the mobile phases. The analytes were determined by dynamic multiple-reaction monitoring (MRM) in electrospray positive ionization mode (ESI+) and quantified using the external standard method. Matrix standard curves were used to reduce matrix effects. The calibration curves of the 83 target compounds were linear in the mass concentration range of 2-200 µg/L (r>0.995). At three levels of addition, the recoveries were 74.5%-112.4%, and the relative standard deviations (RSDs, n=6) were 0.8%-9.9%. The limits of detection (LODs, S/N≥3) were 0.001-0.023 µg/g, and the limits of quantification (LOQs, S/N≥10) were 0.002-0.076 µg/g. The developed method was used to detect glucocorticoids in 41 cosmetic samples. Fluocinolone acetonide, beclomethasone dipropionate, desonide 21-acetate, and desonide were detected in four samples. The content range of glucocorticoids in the positive samples was 0.53-634.27 µg/g. Notably, desonide 21-acetate, which is not included in the scope of the statutory detection method, was detected in two batches of samples. In conclusion, the proposed method is simple, sensitive, reliable, and suitable for the high-throughput analysis of the 83 glucocorticoids in cosmetics with different matrices. This method could provide reliable technical support for the daily supervision of cosmetics and serve as a supplement to current glucocorticoid standards.
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Cosméticos , Glucocorticoides , Acetona , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Desonida , Cloreto de Sódio , Espectrometria de Massas em Tandem , Ácido Acético , Acetonitrilas , Água , Extração em Fase SólidaRESUMO
Intraluminal lymphatic valves (LVs) and lymphovenous valves (LVVs) are critical to ensure the unidirectional flow of lymphatic fluid. Morphological abnormalities in these valves always cause lymph or blood reflux, and result in lymphedema. However, the underlying molecular mechanism of valve development remains poorly understood. We here report the implication of Efnb2-Ephb4-Rasa1 regulated Erk signaling axis in lymphatic valve development with identification of two new valve structures. Dynamic monitoring of phospho-Erk activity indicated that Erk signaling is spatiotemporally inhibited in some lymphatic endothelial cells (LECs) during the valve cell specification. Inhibition of Erk signaling via simultaneous depletion of zygotic erk1 and erk2 or treatment with MEK inhibitor selumetinib causes lymphatic vessel hypoplasia and lymphatic valve hyperplasia, suggesting opposite roles of Erk signaling during these two processes. ephb4b mutants, efnb2a;efnb2b or rasa1a;rasa1b double mutants all have defective LVs and LVVs and exhibit blood reflux into lymphatic vessels with an edema phenotype. Importantly, the valve defects in ephb4b or rasa1a;rasa1b mutants are mitigated with high-level gata2 expression in the presence of MEK inhibitors. Therefore, Efnb2-Ephb4 signaling acts to suppress Erk activation in valve-forming cells to promote valve specification upstream of Rasa1. Not only do our findings reveal a molecular mechanism of lymphatic valve formation, but also provide a basis for the treatment of lymphatic disorders.
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Células Endoteliais , Vasos Linfáticos , Transdução de Sinais/genética , Fosforilação , Quinases de Proteína Quinase Ativadas por MitógenoRESUMO
BACKGROUND: Inconsistencies remain regarding the effectiveness and safety of leukotriene receptor antagonists (LTRAs) and selective H1-antihistamines (SAHs) for allergic rhinitis (AR). A meta-analysis of randomized controlled trials (RCTs) was conducted to compare the medications. METHODS: Relevant head-to-head comparative RCTs were retrieved by searching the PubMed, Embase, and Cochrane's Library databases from inception to April 20, 2020. A random-effects model was applied to pool the results. Subgroup analyses were performed for seasonal and perennial AR. RESULTS: Fourteen RCTs comprising 4458 patients were included. LTRAs were inferior to SAHs in terms of the daytime nasal symptoms score (mean difference [MD]: 0.05, 95% confidence interval [CI] 0.02 to 0.08, p = 0.003, I2 = 89%) and daytime eye symptoms score (MD: 0.05, 95% CI 0.01 to 0.08, p = 0.009, I2 = 89%), but were superior in terms of the nighttime symptoms score (MD: - 0.04, 95% CI - 0.06 to - 0.02, p < 0.001, I2 = 85%). The effects of the two treatments on the composite symptom score (MD: 0.02, 95% CI - 0.02 to 0.05, p = 0.30, I2 = 91%) and rhinoconjunctivitis quality-of-life questionnaire (RQLQ) (MD: 0.01, 95% CI - 0.05 to 0.07, p = 0.71, I2 = 99%) were similar. Incidences of adverse events were comparable (odds ratio [OR]: 0.97, 95% CI 0.75 to 1.25, p = 0.98, I2 = 0%). These results were mainly obtained from studies on seasonal AR. No significant publication bias was detected. CONCLUSIONS: Although both treatments are safe and effective in improving the quality of life (QoL) in AR patients, LTRAs are more effective in improving nighttime symptoms but less effective in improving daytime nasal symptoms compared to SAHs.
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OBJECTIVE: This study aimed to provide insight into the effect of time interval between loop electrosurgical excision procedure (LEEP) and subsequent hysterectomy on postoperative infectious morbidity in cervical neoplasia patients. METHODS: In this retrospective cohort study, a total of 1172 medical records of patients who were diagnosed with high grade cervical intraepithelial neoplasia (HSIL) or invasive cancer underwent a subsequent hysterectomy after LEEP at the International Peace Maternity and Child Health Hospital (IPMCH) in Shanghai, China from January 2008 to December 2019 were collected. The study outcome was postoperative infectious morbidity within 30 days after a hysterectomy. Overall and surgical approach specific effect of time interval on infectious morbidity was estimated using logistic regression in crude and adjusted models. RESULTS: There was an inverse association between time interval and postoperative infectious morbidity in HSIL or invasive cancer patients (OR=0.99, 95% CI: 0.98-1.00, p=0.0079). When trisecting time interval into three parts, the top tertile time interval (34-90 days) was also inversely associated with infectious morbidity compared with bottom tertile (0-16 days), independent of stage, surgical approach, operative time and estimated blood loss (OR=0.66,95% CI: 0.43-1.00, P=0.0487). A test for interaction between time interval and surgical approach on infectious morbidity was significant (P values for interaction= 0.0352). Longer time interval significantly reduced the risk of infectious morbidity in the laparoscopic group (OR = 0.37, 95% CI: 0.17-0.78), while no statistically significant effects were observed in patients who underwent vaginal or open abdominal hysterectomy. CONCLUSION: The time interval and surgical approach can interactively affect the risk of postoperative infectious morbidity in cervical neoplasia patients who underwent a hysterectomy after LEEP. Our data suggest that compared with vaginal or open abdominal hysterectomy, laparoscopic hysterectomy required a longer time interval (34-90 days) to reduce the risk of infectious morbidity.
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Expression of Ki-67 and P16 proteins in cervical cancer and precancerous lesions of young women and the diagnostic value for cervical cancer and precancerous lesions were investigated. A total of 64 paraffin-embedded specimens of uterus tissue from young female patients who were admitted to Jiading District Central Hospital Affiliated to Shanghai University of Medicine and Health Sciences from January 2015 to December 2017 were selected. According to pathological examination, the specimens were divided into chronic cervicitis group (control group, 10 cases), low-grade squamous intraepithelial lesion (LSIL) group (12 cases), high-grade squamous intraepithelial lesion (HSIL) group (20 cases) and squamous carcinoma of the cervix (SCC) group (22 cases). Expression of Ki-67 and P16 protein was detected by immunohistochemistry and the diagnostic values were analyzed. Positive rates of Ki-67 and P16 expression in HSIL and SCC groups were significantly higher than those in LSIL and control groups (P<0.05), but there was no significant difference between LSIL and control groups (P>0.05). Spearman's analysis showed that the expression levels of Ki-67 and P16 were positively correlated with the degree of cervical lesions (rs=0.725; rs=0.829), and their expression levels were also positively correlated (rs=0.772). Sensitivity and specificity analysis showed that the Ki-67 diagnosis has higher sensitivity (95.2%), but the specificity is poor (86.7%). Diagnosis using P16 has high specificity (94.6%), but the sensitivity is poor (85.4%). When the two were combined for diagnosis, sensitivity (94.8%) and specificity (93.2%) were both at a high level. The combined detection of Ki-67 and P16 protein has a high application prospect as an auxiliary diagnosis of SCC.
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Migrasomes are recently identified vesicular organelles that form on retraction fibres behind migrating cells. Whether migrasomes are present in vivo and, if so, the function of migrasomes in living organisms is unknown. Here, we show that migrasomes are formed during zebrafish gastrulation and signalling molecules, such as chemokines, are enriched in migrasomes. We further demonstrate that Tspan4 and Tspan7 are required for migrasome formation. Organ morphogenesis is impaired in zebrafish MZtspan4a and MZtspan7 mutants. Mechanistically, migrasomes are enriched on a cavity underneath the embryonic shield where they serve as chemoattractants to ensure the correct positioning of dorsal forerunner cells vegetally next to the embryonic shield, thereby affecting organ morphogenesis. Our study shows that migrasomes are signalling organelles that provide specific biochemical information to coordinate organ morphogenesis.
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Embrião não Mamífero/metabolismo , Morfogênese/fisiologia , Organelas/metabolismo , Proteínas de Peixe-Zebra/genética , Animais , Padronização Corporal/fisiologia , Movimento Celular/genética , Movimento Celular/fisiologia , Desenvolvimento Embrionário/fisiologia , Gastrulação/fisiologia , Organelas/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Peixe-Zebra/embriologiaRESUMO
Prpf4 (pre-mRNA processing factor 4), a key component of spliceosome, plays critical roles in pre-mRNA splicing and its mutations result in retinitis pigmentosa due to photoreceptor defects. In this study, we characterized a zebrafish prpf4t243 mutant harboring a Tol2 transposon-based gene trap cassette in the third intron of the prpf4 gene. Cells in the brain and spinal cord gradually undergo p53-dependent apoptosis after 28 hpf in prpf4t243 mutants, suggesting that a widespread function of prpf4 in neural cell survival. In addition, prpf4 is essential for survival of posterior lateral line primordial (pLLP) cells. prpf4 deficiency perturbs Fgf, Wnt/ß-catenin and chemokine signaling pathways and impairs pLLP migration. RNA-Seq analysis suggests that prpf4 deficiency may impair spliceosome assembly, leading to compensatory upregulation of core spliceosomal genes and alteration of pre-mRNA splicing. Taken together, our studies uncover an essential role of prpf4 in pre-mRNA splicing, cell survival and pLLP migration.
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Sistema da Linha Lateral/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Apoptose , Encéfalo/citologia , Encéfalo/metabolismo , Movimento Celular , Sobrevivência Celular , Regulação da Expressão Gênica no Desenvolvimento , Íntrons , Sistema da Linha Lateral/citologia , Sistema da Linha Lateral/embriologia , Splicing de RNA , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Spliceossomos/genética , Spliceossomos/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genéticaRESUMO
INTRODUCTION: Antibiotic resistance is a growing concern in health care. Methicillin-resistant Staphylococcus aureus (MRSA), forming biofilms, is a common cause of resistant orthopedic implant infections. Gentamicin is a crucial antibiotic preventing orthopedic infections. Silica-gentamicin (SiO2-G) delivery systems have attracted significant interest in preventing the formation of biofilms. However, compelling scientific evidence addressing their efficacy against planktonic MRSA and MRSA biofilms is still lacking, and their safety has not extensively been studied. MATERIALS AND METHODS: In this work, we have investigated the effects of SiO2-G nanohybrids against planktonic MRSA as well as MRSA and Escherichia coli biofilms and then evaluated their toxicity in zebrafish embryos, which are an excellent model for assessing the toxicity of nanotherapeutics. RESULTS: SiO2-G nanohybrids inhibited the growth and killed planktonic MRSA at a minimum concentration of 500 µg/mL. SiO2-G nanohybrids entirely eradicated E. coli cells in biofilms at a minimum concentration of 250 µg/mL and utterly deformed their ultrastructure through the deterioration of bacterial shapes and wrinkling of their cell walls. Zebrafish embryos exposed to SiO2-G nanohybrids (500 and 1,000 µg/mL) showed a nonsignificant increase in mortality rates, 13.4±9.4 and 15%±7.1%, respectively, mainly detected 24 hours post fertilization (hpf). Frequencies of malformations were significantly different from the control group only 24 hpf at the higher exposure concentration. CONCLUSION: Collectively, this work provides the first comprehensive in vivo assessment of SiO2-G nanohybrids as a biocompatible drug delivery system and describes the efficacy of SiO2-G nanohybrids in combating planktonic MRSA cells and eradicating E. coli biofilms.
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Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Gentamicinas/farmacologia , Nanopartículas/toxicidade , Dióxido de Silício/química , Testes de Toxicidade , Animais , Embrião não Mamífero/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Larva/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanopartículas/química , Nanopartículas/ultraestrutura , Peixe-Zebra/embriologiaRESUMO
The non-canonical Wnt/Ca2+ signaling pathway plays important roles in embryonic development, tissue formation and diseases. However, it is unclear how the Wnt ligand-stimulated, G protein-coupled receptor Frizzled activates phospholipases for calcium release. Here, we report that the zebrafish/human phosphatidylinositol transfer protein Sec14l3/SEC14L2 act as GTPase proteins to transduce Wnt signals from Frizzled to phospholipase C (PLC). Depletion of sec14l3 attenuates Wnt/Ca2+ responsive activity and causes convergent and extension (CE) defects in zebrafish embryos. Biochemical analyses in mammalian cells indicate that Sec14l3-GDP forms complex with Frizzled and Dishevelled; Wnt ligand binding of Frizzled induces translocation of Sec14l3 to the plasma membrane; and then Sec14l3-GTP binds to and activates phospholipase Cδ4a (Plcδ4a); subsequently, Plcδ4a initiates phosphatidylinositol-4,5-bisphosphate (PIP2) signaling, ultimately stimulating calcium release. Furthermore, Plcδ4a can act as a GTPase-activating protein to accelerate the hydrolysis of Sec14l3-bound GTP to GDP. Our data provide a new insight into GTPase protein-coupled Wnt/Ca2+ signaling transduction.
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Sinalização do Cálcio , Proteínas de Transporte/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Lipoproteínas/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Transativadores/metabolismo , Via de Sinalização Wnt , Animais , Linhagem Celular , Receptores Frizzled/metabolismo , Humanos , Fosfolipases Tipo C/metabolismo , Peixe-ZebraRESUMO
Photocatalytic CO2 reduction into renewable hydrocarbon solar fuels is considered as a promising strategy to simultaneously address global energy and environmental issues. This study focused on the direct coupling of photocatalytic water splitting and thermocatalytic hydrogenation of CO2 in the conversion of CO2 -H2 O into fuels. Specifically, it was found that direct coupling of thermo- and photocatalysis over Au-Ru/TiO2 leads to activity 15 times higher (T=358â K; ca.â 99 % CH4 selectivity) in the conversion of CO2 -H2 O into fuels than that of photocatalytic water splitting. This is ascribed to the promoting effect of thermocatalytic hydrogenation of CO2 by hydrogen atoms generated in situ by photocatalytic water splitting.
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Dióxido de Carbono/química , Hidrogênio/química , Processos Fotoquímicos , Energia Solar , Catálise , Temperatura Alta , Hidrogenação , Fotólise , ÁguaRESUMO
Hematopoietic stem cells (HSCs) replenish all types of blood cells. It is debating whether HSCs in adults solely originate from the aorta-gonad-mesonephros (AGM) region, more specifically, the dorsal aorta, during embryogenesis. Here, we report that somite hematopoiesis, a previously unwitnessed hematopoiesis, can generate definitive HSCs (dHSCs) in zebrafish. By transgenic lineage tracing, we found that a subset of cells within the forming somites emigrate ventromedially and mix with lateral plate mesoderm-derived primitive hematopoietic cells before the blood circulation starts. These somite-derived hematopoietic precursors and stem cells (sHPSCs) subsequently enter the circulation and colonize the kidney of larvae and adults. RNA-seq analysis reveals that sHPSCs express hematopoietic genes with sustained expression of many muscle/skeletal genes. Embryonic sHPSCs transplanted into wild-type embryos expand during growth and survive for life time with differentiation into various hematopoietic lineages, indicating self-renewal and multipotency features. Therefore, the embryonic origin of dHSCs in adults is not restricted to the AGM.