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1.
Exp Dermatol ; 32(6): 822-830, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36843342

RESUMO

The current study aimed to characterize cellular uptake and bioconversion of retinol in fully differentiated human immortalized keratinocytes cells (HaCaT) and artificial skin by measuring the cell integrity of skin barriers, time-dependent transport of retinol, and bioconversion to its metabolites. The expression of epidermal differentiation related genes including Keratin 1 (KRT1), Keratin 10 (KRT10), and Involucrin (IVL) significantly increased in differentiated HaCaT. TEER of HaCaT did not decrease after incubating retinol compared to control (p > 0.05), indicating that retinol tends to maintain strength and integrity of epidermal barrier. TEER of artificial skin decreased treatment of retinol for 2 h, but it was recovered after 4 h. During retinol transport, metabolite was eluted at 13.37 and 13.82 min of basal medium of both keratinocytes and artificial skin, which was identified as retinoic acid by product ion of m/z 283.47. Retinol appeared to be accumulated in keratinocytes, but its uptake tends to be reduced in a time-dependent manner. Retinoic acid converted from retinol in keratinocytes was time dependently transported. In case of artificial skin, retinol was mostly found in apical at initial incubation time, but it was reduced during incubation for 24 h. Retinoic acid was time-dependently found in a basal, which was converted via epidermis-dermis. Results from the current study suggest that topical application of retinol to human skin optimal concentration and time exposure could maintain epidermal barrier function and promote skin function due to its remarkable bioconversion to retinoic acid in the epidermis-dermis.


Assuntos
Pele Artificial , Vitamina A , Humanos , Queratinócitos/metabolismo , Epiderme/metabolismo , Tretinoína/metabolismo , Derme/metabolismo
2.
Artigo em Inglês | MEDLINE | ID: mdl-37326606

RESUMO

A Gram-stain-negative, aerobic, reddish-coloured, rod-shaped and non-motile strain PAMC 29467T, was isolated from freshwater of the pond in Cambridge Bay, Canada. Strain PAMC 29467T was closely related to Hymenobacter yonginensis (98.1 % 16S rRNA gene similarity). Genomic relatedness analyses showed that strain PAMC 29467T is distinguishable from H. yonginensis based on average nucleotide identity (91.3 %) and digital DNA-DNA hybridization values (39.3 %). The major fatty acids (>10 %) of strain PAMC 29467T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C15 : 0 iso, C16 : 1 ω5c and summed feature 4 (C17 : 1 iso l and/or anteiso B). The major respiratory quinone was menaquinone-7. The genomic DNA G+C content was 61.5 mol%. Strain PAMC 29467T was separated from the type species in the genus Hymenobacter by its distinct phylogenetic position and some physiological characteristics. As a result, a novel species is proposed, with the name Hymenobacter canadensis sp. nov. (type strain, PAMC 29467T=KCTC 92787T=JCM 35843T).


Assuntos
Cytophagaceae , Ácidos Graxos , Ácidos Graxos/química , Lagoas , Filogenia , RNA Ribossômico 16S/genética , Baías , Análise de Sequência de DNA , DNA Bacteriano/genética , Composição de Bases , Técnicas de Tipagem Bacteriana , Água Doce , Vitamina K 2
3.
Int J Mol Sci ; 24(15)2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37569558

RESUMO

Melanocortins play crucial roles in regulating the stress response, inflammation, and skin pigmentation. In this review, we focus on the melanocortin 1 receptor (MC1R), a G protein-coupled receptor primarily known for regulating skin pigmentation and exhibiting anti-inflammatory effects. First, we provide an overview of the structure, signaling pathways, and related diseases of MC1R. Next, we discuss the potential therapeutic use of synthetic peptides and small molecule modulators of MC1R, highlighting the development of various drugs that enhance stability through amino acid sequence modifications and small molecule drugs to overcome limitations associated with peptide characteristics. Notably, MC1R-targeted drugs have applications beyond skin pigmentation-related diseases, which predominantly affect MC1R in melanocytes. These drugs can also be useful in treating inflammatory diseases with MC1R expression present in various cells. Our review underscores the potential of MC1R-targeted drugs to treat a wide range of diseases and encourages further research in this area.


Assuntos
Melanócitos , Receptor Tipo 1 de Melanocortina , Melanócitos/metabolismo , Peptídeos/farmacologia , Receptor Tipo 1 de Melanocortina/genética , Receptor Tipo 1 de Melanocortina/metabolismo , Transdução de Sinais , Pigmentação da Pele , Humanos
4.
PLoS Genet ; 15(7): e1008292, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31339933

RESUMO

Red light promotes germination after activating phytochrome phyB, which destabilizes the germination repressor PIF1. Early upon seed imbibition, canopy light, unfavorable for photosynthesis, represses germination by stabilizing PIF1 after inactivating phyB. Paradoxically, later upon imbibition, canopy light stimulates germination after activating phytochrome phyA. phyA-mediated germination is poorly understood and, intriguingly, is inefficient, compared to phyB-mediated germination, raising the question of its physiological significance. A genetic screen identified polyamine uptake transporter 2 (put2) mutants that overaccumulate polyamines, a class of antioxidant polycations implicated in numerous cellular functions, which we found promote phyA-mediated germination. In WT seeds, our data suggest that canopy light represses polyamines accumulation through PIF1 while red light promotes polyamines accumulation. We show that canopy light also downregulates PIF1 levels, through phyA; however, PIF1 reaccumulates rapidly, which limits phyA-mediated germination. High polyamines levels in decaying seeds bypass PIF1 repression of germination and stimulate phyA-mediated germination, suggesting an adaptive mechanism promoting survival when viability is compromised.


Assuntos
1-Pirrolina-5-Carboxilato Desidrogenase/genética , Sistemas de Transporte de Aminoácidos/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fitocromo A/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , 1-Pirrolina-5-Carboxilato Desidrogenase/metabolismo , Sistemas de Transporte de Aminoácidos/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação para Baixo , Germinação , Luz , Mutação , Poliaminas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
5.
BMC Ophthalmol ; 21(1): 76, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33557770

RESUMO

BACKGROUND: Increased use of the transorbital approach (TOA) warrants greater understanding of the risk of increased intraocular pressure (IOP) and intraorbital pressure (IORP) due to orbital compression. We aimed to investigate the changes in IOP and IORP in response to orbital retraction in TOA and establish a method for the continuous measurement of intraoperative IORP. METHODS: We assessed nine patients who underwent TOA surgery from January 2017 to December 2019, in addition to five cadavers. IORP and IOP were measured using a cannula needle monitor, tonometer, cuff manometer, and micro strain gauge monitor. RESULTS: In all nine clinical cases and five cadavers, increased physical compression of the orbit increased the IOP and IORP in a curvilinear pattern. In clinical cases, when the orbit was compressed 1.5 cm from the lateral margin in the sagittal plane, the mean IOP and IORP were 25.4 ± 5.2 mmHg and 14 ± 9.2 mmH2O, respectively. The IORP satisfactorily reflected the IOP (Pearson correlation coefficient = 0.824, p < 0.001). CONCLUSION: We measured IOP and IORP simultaneously during orbital compression to gain basic information on pressure changes. In clinical cases, the change in the IOP could be conveniently and noninvasively monitored using continuous IORP measurements.


Assuntos
Glaucoma , Pressão Intraocular , Endoscopia , Humanos , Órbita/diagnóstico por imagem , Órbita/cirurgia , Tonometria Ocular
6.
Acta Neurochir (Wien) ; 162(9): 2119-2128, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32440923

RESUMO

BACKGROUND: We devised a biportal endoscopic transorbital approach (BiETOA) to gain surgical freedom by making a port for the endoscope and investigated the benefits and limitations of BiETOA. METHODS: A cylindrical port was designed and 3-D printed using biocompatible material. The port was inserted through a keyhole between the superolateral side of the orbital rim and the temporal muscle. An endoscope was inserted through the port, and other instruments were inserted through the conventional transorbital route. BiETOA was used to dissect eight cadaveric heads, and the angle of attack and surgical freedom were assessed. RESULTS: The mean maximal angle of attack was significantly different in BiETOA and endoscopic transorbital approach (ETOA) (P < 0.01) but not in BiETOA and ETOA lateral orbital rim (LOR) osteotomy (P = 0.207, P = 0.21). The mean surgical freedom was significantly different in BiETOA and ETOA (P < 0.01) and in BiETOA and ETOA LOR osteotomy (P < 0.01). In the clinical cases, tumors were removed successfully without any complications. CONCLUSIONS: BiETOA provided increased surgical freedom and better visibility of deep target lesion and resulted in good surgical and cosmetic outcomes.


Assuntos
Cirurgia Endoscópica por Orifício Natural/métodos , Órbita/cirurgia , Cadáver , Endoscópios , Humanos , Cirurgia Endoscópica por Orifício Natural/efeitos adversos , Cirurgia Endoscópica por Orifício Natural/instrumentação , Órbita/anatomia & histologia , Complicações Pós-Operatórias/prevenção & controle , Impressão Tridimensional
7.
J Neurosci ; 38(17): 4076-4092, 2018 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-29572432

RESUMO

Shank2 is an excitatory postsynaptic scaffolding protein implicated in synaptic regulation and psychiatric disorders including autism spectrum disorders. Conventional Shank2-mutant (Shank2-/-) mice display several autistic-like behaviors, including social deficits, repetitive behaviors, hyperactivity, and anxiety-like behaviors. However, cell-type-specific contributions to these behaviors have remained largely unclear. Here, we deleted Shank2 in specific cell types and found that male mice lacking Shank2 in excitatory neurons (CaMKII-Cre;Shank2fl/fl) show social interaction deficits and mild social communication deficits, hyperactivity, and anxiety-like behaviors. In particular, male mice lacking Shank2 in GABAergic inhibitory neurons (Viaat-Cre;Shank2fl/fl) display social communication deficits, repetitive self-grooming, and mild hyperactivity. These behavioral changes were associated with distinct changes in hippocampal and striatal synaptic transmission in the two mouse lines. These results indicate that cell-type-specific deletions of Shank2 in mice lead to differential synaptic and behavioral abnormalities.SIGNIFICANCE STATEMENT Shank2 is an abundant excitatory postsynaptic scaffolding protein implicated in the regulation of excitatory synapses and diverse psychiatric disorders including autism spectrum disorders. Previous studies have reported in vivo functions of Shank2 mainly using global Shank2-null mice, but it remains largely unclear how individual cell types contribute to Shank2-dependent regulation of neuronal synapses and behaviors. Here, we have characterized conditional Shank2-mutant mice carrying the Shank2 deletion in excitatory and inhibitory neurons. These mouse lines display distinct alterations of synaptic transmission in the hippocampus and striatum that are associated with differential behavioral abnormalities in social, repetitive, locomotor, and anxiety-like domains.


Assuntos
Ansiedade/genética , Neurônios GABAérgicos/metabolismo , Relações Interpessoais , Proteínas do Tecido Nervoso/genética , Transmissão Sináptica , Animais , Ansiedade/fisiopatologia , Corpo Estriado/citologia , Corpo Estriado/metabolismo , Corpo Estriado/fisiologia , Neurônios GABAérgicos/fisiologia , Hipocampo/citologia , Hipocampo/metabolismo , Hipocampo/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora , Proteínas do Tecido Nervoso/metabolismo , Fenótipo
8.
Plant Cell ; 28(6): 1388-405, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27303023

RESUMO

The bHLH transcription factor PHYTOCHROME INTERACTING FACTOR1 (PIF1) binds G-box elements in vitro and inhibits light-dependent germination in Arabidopsis thaliana A previous genome-wide analysis of PIF1 targeting indicated that PIF1 binds 748 sites in imbibed seeds, only 59% of which possess G-box elements. This suggests the G-box is not the sole determinant of PIF1 targeting. The targeting of PIF1 to specific sites could be stabilized by PIF1-interacting transcription factors (PTFs) that bind other nearby sequence elements. Here, we report PIF1 targeting sites are enriched with not only G-boxes but also with other hexameric sequence elements we named G-box coupling elements (GCEs). One of these GCEs possesses an ACGT core and serves as a binding site for group A bZIP transcription factors, including ABSCISIC ACID INSENSITIVE5 (ABI5), which inhibits seed germination in abscisic acid signaling. PIF1 interacts with ABI5 and other group A bZIP transcription factors and together they target a subset of PIF1 binding sites in vivo. In vitro single-molecule fluorescence imaging confirms that ABI5 facilitates PIF1 binding to DNA fragments possessing multiple G-boxes or the GCE alone. Thus, we show in vivo PIF1 targeting to specific binding sites is determined by its interaction with PTFs and their binding to GCEs.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Sítios de Ligação/genética , Sítios de Ligação/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Ligação Proteica/genética , Ligação Proteica/fisiologia , Fatores de Transcrição/genética
9.
Nanotechnology ; 29(36): 365202, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-29920183

RESUMO

The ovonic threshold switch (OTS) based on the voltage snapback of amorphous chalcogenides possesses several desirable characteristics: bidirectional switching, a controllable threshold voltage (V th) and processability for three-dimensional stackable devices. Among the materials that can be used as OTS, GeSe has a strong glass-forming ability (∼350 °C crystallization temperature), with a simple binary composition. Described herein is a new method of depositing GeSe films through atomic layer deposition (ALD), using HGeCl3 and [(CH3)3Si]2Se as Ge and Se precursors, respectively. The stoichiometric GeSe thin films were formed through a ligand exchange reaction between the two precursor molecules, without the adoption of an additional reaction gas, at low substrate temperatures ranging from 70 °C-150 °C. The pseudo-saturation behavior required a long time of Ge precursor injection to achieve the saturation growth rate. This was due to the adverse influence of the physisorbed precursor and byproduct molecules on the efficient chemical adsorption reaction between the precursors and reaction sites. To overcome the slow saturation and excessive use of the Ge precursor, the discrete feeding method (DFM), where HGeCl3 is supplied multiple times consecutively with subdivided pulse times, was adopted. DFM led to the saturation of the GeSe growth rate at a much shorter total injection time of the Ge precursor, and improved the film density and oxidation resistance properties. The GeSe film grown via DFM exhibited a short OTS time of ∼40 ns, a ∼107 ON/OFF current ratio, and ∼104 selectivity. The OTS behavior was consistent with the modified Poole-Frenkel mechanism in the OFF state. In contrast, the similar GeSe film grown through the conventional ALD showed a low density and high vulnerability to oxidation, which prevented the OTS performance. The ALD method of GeSe films introduced here will contribute to the fabrication of a three-dimensionally integrated memory as a selector device for preventing sneak current.

10.
Childs Nerv Syst ; 34(6): 1199-1206, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29679197

RESUMO

PURPOSE: Moyamoya disease (MMD) commonly leads to neurocognitive impairment. This study was carried out to show that temporal encephaloduroarteriosynangiosis (EDAS) has a positive neuropsychological impact on pediatric MMD patients. METHODS: Fifty-five participants diagnosed with MMD from 2008 to 2014 were included in this retrospective study. The mean age at the preoperative evaluation was 9.5 years and the mean age at postoperative evaluation was 10.4. The average interval of initial and follow-up test was 10 months. K-WISC-III, Rey-Kim memory test, Children's Color Trails test (CCTT), Wisconsin Card Sorting Test (WCST), and Advanced Test of Attention (ATA) were used to evaluate patient's neurocognitive profile. RESULTS: In this study, preoperative and postoperative neuropsychological fields were compared. Prior operation, pediatric MMD patients showed 54.2% deficit of inattention but only around 2.5% deficit in verbal memory recall function. There was a significant increase of performance IQ and PO score component of PIQ improved almost 10 scores after surgery. For memorial function, there was an improvement of approximately 10 scores in MQ after the surgery. This study also showed parietal activation following surgical treatment which enhanced the ability to interpret visual materials, to register and to retrieve visual information. Interestingly, despite the parietal cover surgery, there was a significant improvement of performance on WCST and CCTT measuring the prefrontal executive function. Concerning failure to maintain set, no significant postoperative improvements were made. However, simple and selective visual attention on ATA was significantly improved postoperatively. CONCLUSIONS: The results from neuropsychological field comparison testifies the effectiveness of temporal EDAS in pediatric MMD patients. The surgery not only enhances the blood flow in operative regions, but it also improves the broad cerebral function including frontoparietal domains. Such alteration leads to overall advancement in cognitive function which are impaired due to MMD.


Assuntos
Revascularização Cerebral/métodos , Doença de Moyamoya/psicologia , Doença de Moyamoya/cirurgia , Adolescente , Criança , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Estudos Retrospectivos , Resultado do Tratamento
11.
J Neurosci ; 36(48): 12129-12143, 2016 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-27903723

RESUMO

Shank2 is a multidomain scaffolding protein implicated in the structural and functional coordination of multiprotein complexes at excitatory postsynaptic sites as well as in psychiatric disorders, including autism spectrum disorders. While Shank2 is strongly expressed in the cerebellum, whether Shank2 regulates cerebellar excitatory synapses, or contributes to the behavioral abnormalities observed in Shank2-/- mice, remains unexplored. Here we show that Shank2-/- mice show reduced excitatory synapse density in cerebellar Purkinje cells in association with reduced levels of excitatory postsynaptic proteins, including GluD2 and PSD-93, and impaired motor coordination in the Erasmus test. Shank2 deletion restricted to Purkinje cells (Pcp2-Cre;Shank2fl/fl mice) leads to similar reductions in excitatory synapse density, synaptic protein levels, and motor coordination. Pcp2-Cre;Shank2fl/fl mice do not recapitulate autistic-like behaviors observed in Shank2-/- mice, such as social interaction deficits, altered ultrasonic vocalizations, repetitive behaviors, and hyperactivity. However, Pcp2-Cre;Shank2fl/fl mice display enhanced repetitive behavior in the hole-board test and anxiety-like behavior in the light-dark test, which are not observed in Shank2-/- mice. These results implicate Shank2 in the regulation of cerebellar excitatory synapse density, motor coordination, and specific repetitive and anxiety-like behaviors. SIGNIFICANCE STATEMENT: The postsynaptic side of excitatory synapses contains multiprotein complexes, termed the postsynaptic density, which contains receptors, scaffolding/adaptor proteins, and signaling molecules. Shank2 is an excitatory postsynaptic scaffolding protein implicated in the formation and functional coordination of the postsynaptic density and has been linked to autism spectrum disorders. Using Shank2-null mice and Shank2-conditional knock-out mice with a gene deletion restricted to cerebellar Purkinje cells, we explored functions of Shank2 in the cerebellum. We found that Shank2 regulates excitatory synapse density, motor coordination, and specific repetitive and anxiety-like behaviors, but is not associated with autistic-like social deficits or repetitive behaviors.


Assuntos
Ansiedade/fisiopatologia , Cerebelo/fisiopatologia , Transtornos Traumáticos Cumulativos/fisiopatologia , Proteínas do Tecido Nervoso/metabolismo , Desempenho Psicomotor/fisiologia , Sinapses/patologia , Animais , Comportamento Animal/fisiologia , Contagem de Células , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Sinapses/fisiologia
12.
J Virol ; 90(21): 9644-9653, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27535046

RESUMO

HBx, a small regulatory protein of hepatitis B virus (HBV), augments viral DNA replication by stimulating viral transcription. Among numerous reported HBx-binding proteins, DDB1 has drawn attention, because DDB1 acts as a substrate receptor of the Cul4-DDB1 ubiquitin E3 ligase. Previous work reported that the DDB1-HBx interaction is indispensable for HBx-stimulated viral DNA replication, suggesting that the Cul4-DDB1 ubiquitin E3 ligase might target cellular restriction factors for ubiquitination and proteasomal degradation. To gain further insight into the DDB1-HBx interaction, we generated HBx mutants deficient for DDB1 binding (i.e., R96A, L98A, and G99A) and examined whether they support HBx-stimulated viral DNA replication. In contrast to data from previous reports, our results showed that the HBx mutants deficient for DDB1 binding supported viral DNA replication to nearly wild-type levels, revealing that the DDB1-HBx interaction is largely dispensable for HBx-stimulated viral DNA replication. Instead, we found that DDB1 directly stimulates viral transcription regardless of HBx expression. Through an HBV infection study, importantly, we demonstrated that DDB1 stimulates viral transcription from covalently closed circular DNA, a physiological template for viral transcription. Overall, we concluded that DDB1 stimulates viral transcription via a mechanism that does not involve an interaction with HBx. IMPORTANCE: DDB1 constitutes a cullin-based ubiquitin E3 ligase, where DDB1 serves as an adaptor linking the cullin scaffold to the substrate receptor. Previous findings that the DDB1-binding ability of HBx is essential for HBx-stimulated viral DNA replication led to the hypothesis that HBx could downregulate host restriction factors that limit HBV replication through the cullin ubiquitin E3 ligase that requires the DDB1-HBx interaction. Consistent with this hypothesis, recent work identified Smc5/6 as a host restriction factor that is regulated by the viral cullin ubiquitin E3 ligase. In contrast, here we found that the DDB1-HBx interaction is largely dispensable for HBx-stimulated viral DNA replication. Instead, our results clearly showed that DDB1, regardless of HBx expression, enhances viral transcription. Overall, besides its role in the viral cullin ubiquitin E3 ligase, DDB1 itself stimulates viral transcription via HBx-independent mechanisms.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Vírus da Hepatite B/metabolismo , Transativadores/metabolismo , Linhagem Celular Tumoral , Proteínas Culina/metabolismo , Replicação do DNA/fisiologia , DNA Circular/genética , Células HEK293 , Células Hep G2 , Humanos , Ligação Proteica/fisiologia , Transcrição Gênica , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/fisiologia , Proteínas Virais Reguladoras e Acessórias , Replicação Viral/fisiologia
13.
J Exp Bot ; 68(4): 857-869, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27729475

RESUMO

Primary seed dormancy is an important adaptive plant trait whereby seed germination is blocked under conditions that would otherwise be favorable for germination. This trait is found in newly produced mature seeds of many species, but not all. Once produced, dry seeds undergo an aging time period, called dry after-ripening, during which they lose primary dormancy and gradually acquire the capacity to germinate when exposed to favorable germination conditions. Primary seed dormancy has been extensively studied not only for its scientific interest but also for its ecological, phenological, and agricultural importance. Nevertheless, the mechanisms underlying primary seed dormancy and its regulation during after-ripening remain poorly understood. Here we review the principal developmental stages where primary dormancy is established and regulated prior to and during seed after-ripening, where it is progressively lost. We attempt to identify and summarize what is known about the molecular and genetic mechanisms intervening over time in each of these stages.


Assuntos
Dormência de Plantas/fisiologia , Ácido Abscísico/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Endosperma/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Reguladores de Crescimento de Plantas/fisiologia , Fenômenos Fisiológicos Vegetais , Sementes/crescimento & desenvolvimento , Sementes/fisiologia
14.
Foodborne Pathog Dis ; 13(9): 502-8, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27385033

RESUMO

Cattle are a natural reservoir of Shiga toxin-producing Escherichia coli (STEC) and have recently been recognized as a major source of Campylobacter jejuni contamination. While several factors are known to be associated with bacterial colonization, the underlying microbial factors have not been clarified. In this study, we characterized the fecal microbiota of dairy cattle (n = 24) using next-generation sequencing to elucidate the intestinal bacterial communities and the microbial diversity in relation to the presence of the foodborne pathogens STEC and C. jejuni (STEC-positive samples, n = 9; STEC-negative samples, n = 15; C. jejuni-positive samples, n = 9; and C. jejuni-negative samples, n = 15). While no significant differences were observed in alpha diversity between STEC-positive and STEC-negative samples, a high diversity index was observed in C. jejuni-positive samples compared to C. jejuni-negative samples. Nine phyla, 13 classes, 18 orders, 47 families, 148 genera, and 261 species were found to be the core microbiota in dairy cattle, covering 80.0-100.0% of the fecal microbial community. Diverse microbial communities were observed between cattle shedding foodborne pathogens and nonshedding cattle. C. jejuni-positive cattle had a higher relative abundance of Bacteroidetes (p = 0.035) and a lower relative abundance of Firmicutes (p = 0.035) compared to C. jejuni-negative cattle. In addition, while the relative abundance of 2 and 6 genera was significantly higher in cattle-shedding STEC and C. jejuni, respectively, the relative abundance of 3 genera was lower in both STEC- and C. jejuni-negative cattle. Our findings provide fundamental information on the bacterial ecology in cattle feces and might be useful in developing strategies to reduce STEC or C. jejuni shedding in dairy cattle, thereby reducing the incidence of STEC infection and campylobacteriosis in humans.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter jejuni/isolamento & purificação , Doenças dos Bovinos/microbiologia , Infecções por Escherichia coli/veterinária , Escherichia coli Shiga Toxigênica/isolamento & purificação , Animais , Derrame de Bactérias , Infecções por Campylobacter/diagnóstico , Campylobacter jejuni/genética , Bovinos , DNA Bacteriano/análise , Indústria de Laticínios , Infecções por Escherichia coli/diagnóstico , Fezes/microbiologia , Feminino , Microbiologia de Alimentos , Microbiota , Leite/microbiologia , República da Coreia , Escherichia coli Shiga Toxigênica/genética
15.
Plant Cell Physiol ; 55(12): 2177-88, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25320211

RESUMO

Ginseng is a medicinal herb that requires cultivation under shade conditions, typically for 4-6 years, before harvesting. The principal components of ginseng are ginsenosides, glycosylated tetracyclic terpenes. Dammarene-type ginsenosides are classified into two groups, protopanaxadiol (PPD) and protopanaxatriol (PPT), based on their hydroxylation patterns, and further diverge to diverse ginsenosides through differential glycosylation. Three early enzymes, dammarenediol-II synthase (DS) and two P450 enzymes, protopanaxadiol synthase (PPDS) and protopanaxatriol synthase (PPTS), have been reported, but glycosyltransferases that are necessary to synthesize specific ginsenosides have not yet been fully identified. To discover glycosyltransferases responsible for ginsenoside biosynthesis, we sequenced and assembled the ginseng transcriptome de novo and characterized two UDP-glycosyltransferases (PgUGTs): PgUGT74AE2 and PgUGT94Q2. PgUGT74AE2 transfers a glucose moiety from UDP-glucose (UDP-Glc) to the C3 hydroxyl groups of PPD and compound K to form Rh2 and F2, respectively, whereas PgUGT94Q2 transfers a glucose moiety from UDP-Glc to Rh2 and F2 to form Rg3 and Rd, respectively. Introduction of the two UGT genes into yeast together with PgDS and PgPPDS resulted in the de novo production of Rg3. Our results indicate that these two UGTs are key enzymes for the synthesis of ginsenosides and provide a method for producing specific ginsenosides through yeast fermentation.


Assuntos
Ginsenosídeos/metabolismo , Glicosiltransferases/metabolismo , Panax/enzimologia , Glicosiltransferases/genética , Dados de Sequência Molecular , Panax/química , Panax/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Plantas Medicinais , Sapogeninas/metabolismo
16.
Plant Cell ; 23(4): 1404-15, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21467583

RESUMO

A previous study showed that SOMNUS (SOM), which encodes a C3H-type zinc finger protein, is a key negative regulator of seed germination that acts downstream of PHYTOCHROME INTERACTING FACTOR3-LIKE5 (PIL5). However, it was not determined if PIL5 is the sole regulator of SOM expression. Public microarray data suggest that the expression of SOM mRNA is regulated also by ABSCISIC ACID INSENSITIVE3 (ABI3), another key regulator of seed germination. By analyzing abi3 mutants and ABI3 overexpression lines, we show here that ABI3 activates the expression of SOM mRNA collaboratively with PIL5 in imbibed seeds. Chromatin immunoprecipitation analysis coupled with electrophoretic mobility shift assay indicate that ABI3 activates the expression of SOM mRNA by directly binding to two RY motifs present in the SOM promoter in vivo, which is further supported by the greatly decreased expression of a reporter gene driven by a SOM promoter bearing mutated RY motifs. At the protein level, the ABI3 protein interacts with the PIL5 protein. The ABI3-PIL5 interaction, however, does not affect targeting of ABI3 and PIL5 to SOM promoters. Taken together, our results indicate that ABI3 and PIL5 collaboratively activate the expression of SOM mRNA by directly binding to and interacting with each other at the SOM promoter.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Transporte/genética , Regulação da Expressão Gênica de Plantas , Regiões Promotoras Genéticas/genética , Sementes/genética , Arabidopsis/efeitos da radiação , Proteínas de Transporte/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Ligação Proteica/efeitos da radiação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sementes/efeitos da radiação , Fatores de Transcrição
17.
Int J Food Microbiol ; 417: 110704, 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38640816

RESUMO

On-farm dairy processing plants, which are situated close to farms and larger dairy processing facilities, face unique challenges in maintaining environmental hygiene. This can impact various stages of dairy processing. These plants operate on smaller scales and use Low-Temperature-Long-Time (LTLT) pasteurization, making them more susceptible to microbial contamination through direct and indirect contact. Antimicrobial-resistant bacteria found on dairy farms pose risks to human health by potentially transferring resistance via dairy products. Our study aimed to investigate microbial distribution and antimicrobial resistance at four key stages: the farm, pre-pasteurization, post-pasteurization, and processing environments. We assessed microbial distribution by quantifying indicator bacteria and conducting metagenomic analysis. Antimicrobial resistance was examined by identifying resistance phenotypes and detecting resistance genes in bacterial isolates and metagenomes. Our results showed that the indicator bacteria were detected at all stages of on-farm dairy processing. We observed a significant reduction in aerobic microbes and coliforms post-pasteurization. However, contamination of the final dairy products increased, suggesting potential cross-contamination during post-pasteurization. Metagenomic analysis revealed that Pseudomonas, a representative psychrotrophic bacterium, was predominant in both the farm (24.1 %) and pre-pasteurization (65.9 %) stages, indicating microbial transfer from the farms to the processing plants. Post-pasteurization, Pseudomonas and other psychrotrophs like Acinetobacter and Enterobacteriaceae remained dominant. Core microbiota analysis identified 74 genera in total, including 13 psychrotrophic bacteria, across all stages. Of the 59 strains isolated from these plants, 49 were psychrotrophic. Antimicrobial resistance analysis showed that 74.6 % (44/59) of isolates were resistant to at least one antibiotic, with cefoxitin-, ampicillin-, amoxicillin-, and ticarcillin-resistant bacteria present at all stages. Identical antimicrobial resistance patterns were observed in isolates from serial stages of the same farm and season, suggesting bacterial transmission across stages. Additionally, 27.1 % (16/59) of isolates carried plasmid-mediated resistance genes, which were also detected in the metagenomes of non-isolated samples, indicating potential antimicrobial resistance gene transmission and their presence in uncultured bacteria. These findings reveal the persistence of antimicrobial-resistant psychrotrophic bacteria in on-farm dairy processing plants, which pose potential health risks via dairy consumption. Our study underscores the importance of both culture-dependent and culture-independent methods to fully understand their distribution and impact.


Assuntos
Bactérias , Indústria de Laticínios , Farmacorresistência Bacteriana , Metagenômica , Microbiota , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Bactérias/classificação , Farmacorresistência Bacteriana/genética , Fazendas , Antibacterianos/farmacologia , Laticínios/microbiologia , Pasteurização , Microbiologia de Alimentos , Animais , Manipulação de Alimentos/métodos , Humanos , Bovinos , Metagenoma
18.
Adv Mater ; 36(7): e2309314, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37879643

RESUMO

Memristor-based physical reservoir computing (RC) is a robust framework for processing complex spatiotemporal data parallelly. However, conventional memristor-based reservoirs cannot capture the spatial relationship between the time-varying inputs due to the specific mapping scheme assigning one input signal to one memristor conductance. Here, a physical "graph reservoir" is introduced using a metal cell at the diagonal-crossbar array (mCBA) with dynamic self-rectifying memristors. Input and inverted input signals are applied to the word and bit lines of the mCBA, respectively, storing the correlation information between input signals in the memristors. In this way, the mCBA graph reservoirs can map the spatiotemporal correlation of the input data in a high-dimensional feature space. The high-dimensional mapping characteristics of the graph reservoir achieve notable results, including a normalized root-mean-square error of 0.09 in Mackey-Glass time series prediction, a 97.21% accuracy in MNIST recognition, and an 80.0% diagnostic accuracy in human connectome classification.

19.
Toxicol In Vitro ; 97: 105813, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38522493

RESUMO

The aims of the current study included characterizing the intestinal transport mechanism of polystyrene microplastics (MPs) with different charges and sizes in the intestinal epithelial cell model and determining the inhibitory effect of green tea extracts (GTEs) on the intestinal absorption of MPs in Caco-2 cells. The smaller sizes, which included diameters of 0.2 µm, of amine-modified MPs compared to either larger size (1 µm diameter, or carboxylate-MPs (0.2 and 1 µm diameter) significantly lowered the cell viability of caco-2 cells that were measured by MTT assay (p < 0.05). The transported amount (particles/mL of the cell media) of amine-modified MPs by the Caco-2 cell, was not dependent according to the concentrations, energy, or temperature, but it was higher than the carboxylate-modified MPs. The co-treatment of GTEs with the amine-modified MPs inhibited Caco-2 cell cytotoxicity as well as reduced the production of intracellular reactive oxygen species (ROS) in HepG2 generated by the exposure of amine-modified MPs. The GTEs co-treatment also increased trans-epithelial electrical resistances (TEER) and reduced the transportation of Lucifer Yellow via the Caco-2 monolayer compared to only the amine-modified MPs exposure. The GTEs treatment led to a decrease in the number of amine-modified MPs transported to the basal side of the Caco-2 monolayer. The results from our study suggest that the consumption of GTEs could enhance the intestinal barrier function by recovering intestinal epithelial cell damage induced by MPs, which resulted in a decrease of the intestinal absorption of MPs.


Assuntos
Microplásticos , Poliestirenos , Humanos , Poliestirenos/toxicidade , Microplásticos/toxicidade , Plásticos , Células CACO-2 , Antioxidantes , Absorção Intestinal , Chá , Aminas
20.
Plant Cell Physiol ; 54(4): 555-72, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23378449

RESUMO

Seed dormancy, a seed status that prohibits germination even in the presence of inductive germination signals, is a poorly understood process. To identify molecular components that regulate seed dormancy, we screened T-DNA insertion lines and identified a mutant designated honsu (hon). HON loss-of-function mutants display deep seed dormancy, whereas HON-overexpressing lines display shallow seed dormancy. HON encodes a seed-specific group A phosphatase 2C (PP2C) and is one of the major negative regulators of seed dormancy among group A PP2Cs. Like other PP2C family members, HON interacts with PYR1/RCAR11 in the presence of ABA. Our analysis indicates that HON inhibits ABA signaling and activates gibberellic acid signaling, and both of these conditions must be satisfied to promote the release of seed dormancy. However, HON mRNA levels are increased in mutants displaying deep seed dormancy or under conditions that deepen seed dormancy, and decreased in mutants displaying shallow seed dormancy or under conditions that promote the release of seed dormancy. Taken together, our results indicate that the expression of HON mRNA is homeostatically regulated by seed dormancy.


Assuntos
Ácido Abscísico/farmacologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/fisiologia , Fosfoproteínas Fosfatases/metabolismo , Dormência de Plantas/fisiologia , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/fisiologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , DNA Bacteriano , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Fosfoproteínas Fosfatases/genética , Plantas Geneticamente Modificadas/metabolismo , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Proteína Fosfatase 2C
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