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Ischemic stroke is one of the most disabling and fatal diseases around the world. The damaged brain tissues will undergo excessive autophagy, vascular endothelial cells injury, blood-brain barrier (BBB) impairment and neuroinflammation after ischemic stroke. However, there is no unified viewpoint on the underlying mechanism of brain damage. Transforming growth factor-ß1 (TGF-ß1), as a multi-functional cytokine, plays a crucial role in the intricate pathological processes and helps maintain the physiological homeostasis of brain tissues through various signaling pathways after ischemic stroke. In this review, we summarize the protective role of TGF-ß1 in autophagic flux, BBB, vascular remodeling, neuroinflammation and other aspects after ischemic stroke. Based on the review, we believe that TGF-ß1 could serve as a key target for treating ischemic stroke.
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Autofagia , Barreira Hematoencefálica , AVC Isquêmico , Fator de Crescimento Transformador beta1 , Humanos , Fator de Crescimento Transformador beta1/metabolismo , AVC Isquêmico/metabolismo , AVC Isquêmico/patologia , Animais , Barreira Hematoencefálica/metabolismo , Transdução de Sinais , Células Endoteliais/metabolismo , Isquemia Encefálica/metabolismoRESUMO
Neuropeptide S (NPS) was postulated to be a wake-promoting neuropeptide with unknown mechanism, and a mutation in its receptor (NPSR1) causes the short sleep duration trait in humans. We investigated the role of different NPS+ nuclei in sleep/wake regulation. Loss-of-function and chemogenetic studies revealed that NPS+ neurons in the parabrachial nucleus (PB) are wake-promoting, whereas peri-locus coeruleus (peri-LC) NPS+ neurons are not important for sleep/wake modulation. Further, we found that a NPS+ nucleus in the central gray of the pons (CGPn) strongly promotes sleep. Fiber photometry recordings showed that NPS+ neurons are wake-active in the CGPn and wake/REM-sleep active in the PB and peri-LC. Blocking NPS-NPSR1 signaling or knockdown of Nps supported the function of the NPS-NPSR1 pathway in sleep/wake regulation. Together, these results reveal that NPS and NPS+ neurons play dichotomous roles in sleep/wake regulation at both the molecular and circuit levels.
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Neuropeptídeos , Sono , Humanos , Sono/fisiologia , Ponte/fisiologia , Locus Cerúleo/fisiologia , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Receptores Acoplados a Proteínas G/metabolismoRESUMO
The abnormal initiation of autophagy flux in neurons after ischemic stroke caused dysfunction of autophagy-lysosome, which not only led to autophagy flux blockage, but also resulted in autophagic death of neurons. However, the pathological mechanism of neuronal autophagy-lysosome dysfunction did not form a unified viewpoint until now. In this review, taking the autophagy lysosomal dysfunction of neurons as a starting point, we summarized the molecular mechanisms that led to neuronal autophagy lysosomal dysfunction after ischemic stroke, which would provide theoretical basis for the clinical treatment of ischemic stroke.
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Autofagia , AVC Isquêmico , Lisossomos , AVC Isquêmico/metabolismo , AVC Isquêmico/patologia , AVC Isquêmico/terapia , Humanos , Animais , Neurônios/metabolismo , Neurônios/patologia , Lisossomos/patologia , Reperfusão , Proteínas do Tecido Nervoso/metabolismoRESUMO
Sufficient and efficient sleep is crucial for our health. Natural short sleepers can sleep significantly shorter than the average population without a desire for more sleep and without any obvious negative health consequences. In searching for genetic variants underlying the short sleep trait, we found two different mutations in the same gene (metabotropic glutamate receptor 1) from two independent natural short sleep families. In vitro, both of the mutations exhibited loss of function in receptor-mediated signaling. In vivo, the mice carrying the individual mutations both demonstrated short sleep behavior. In brain slices, both of the mutations changed the electrical properties and increased excitatory synaptic transmission. These results highlight the important role of metabotropic glutamate receptor 1 in modulating sleep duration.
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Receptores de Glutamato Metabotrópico/genética , Sono/genética , Animais , Análise Mutacional de DNA , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Hipocampo/fisiologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Modelos Animais , Mutação , Plasticidade Neuronal/fisiologia , Técnicas de Patch-Clamp , Linhagem , Polissonografia , Receptores de Glutamato Metabotrópico/metabolismo , Fatores de Tempo , Sequenciamento do ExomaRESUMO
BACKGROUND/OBJECTIVES: For treatment of large bone defects challenging in orthopaedic clinics, bone graft substitutes are commonly used for the majority of surgeons. It would be proposed in the current study that our bioactive scaffolds could additionally serve as a local delivery system for therapeutic small molecule agents capable of providing support to enhance biological bone repair. METHODS: In this study, composite scaffolds made of poly (lactic-co-glycolic acid) (PLGA) and tricalcium phosphate (TCP) named by P/T was fabricated by a low-temperature rapid prototyping technique. For optimizing the scaffolds, the phytomolecule icaritin (ICT) was incorporated into P/T scaffolds called P/T/ICT. The osteogenic efficacies of the two groups of scaffolds were compared in a successfully established calvarial defect model in rats. Bone regeneration was evaluated by X-ray, micro-computerised tomography (micro-CT), and histology at weeks 4 and/or 8 post-implantation. In vitro induction of osteogenesis and osteoclastogenesis was established for identification of differentiation potentials evoked by icaritin in primary cultured precursor cells. RESULTS: The results of radiographies and decalcified histology demonstrated more area and volume fractions of newly formed bone within bone defect sites implanted with P/T/ICT scaffold than that with P/T scaffold. Undecalcified histological results presented more osteoid and mineralized bone tissues, and also more active bone remodeling in P/T/ICT group than that in P/T group. The results of histological staining in osteoclast-like cells and newly formed vessels indicated favorable biocompatibility, rapid bioresorption and more new vessel growth in P/T/ICT scaffolds in contrast to P/T scaffolds. Based on in vitro induction, the results presented that icaritin could significantly facilitate osteogenic differentiation, while suppressed adipogenic differentiation. Meanwhile, icaritin demonstrated remarkable inhibition of osteoclastogenic differentiation. CONCLUSION: The finding that P/T/ICT composite scaffold can enhance bone regeneration in calvarial bone defects through facilitating effective bone formation and restraining excessive bone resorption. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The osteogenic bioactivity of icaritin facilitated PLGA/TCP/icartin composite scaffold to exert significant bone regeneration in calvarial defects in rat model. It might form an optimized foundation for potential clinical validation in bone defects application.
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Purpose: This study aimed to evaluate the microbial contamination level and its influencing factors of rigid gas permeable (RGP) trial lenses and lens cases in China.Materials and Methods: A total of 107 RGP trial lenses and lens cases were collected from 7 main hospitals or optometric centers in China. Three sites including the lenses, case interiors and case screw tops were sampled for bacterial and fungal culture and identification. The contamination rates of these three sites and their relationship with lens care regimes were further analyzed.Results: The overall contamination rate was 73.8% for either lenses or cases, and 43.0% of lenses, 57.0% of case interiors and 65.4% of case screw tops respectively. The most frequently isolated microorganisms were Serratia spp., Burkholderia spp., Pandoraea spp., and Achromobacter spp. from all three sites. The contamination rate was positively related to the lens use frequency. Compared with dry-stored lenses, the contamination rate was significantly higher in wet-stored group (P < .001*). Inadequate disinfection and improper lens and case care regimes were also associated with higher contamination rates.Conclusions: Our study reported that the RGP trial lenses and cases used for fittings had a considerably high contamination rate. The safe use of RGP trial lenses and education of optometrists on the regular maintenance of trial lenses should be emphasized.
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Bactérias/isolamento & purificação , Lentes de Contato/microbiologia , Contaminação de Equipamentos/estatística & dados numéricos , Equipamentos e Provisões/microbiologia , Fungos/isolamento & purificação , Adulto , Técnicas Bacteriológicas , China/epidemiologia , Soluções para Lentes de Contato , Feminino , Humanos , Masculino , Pirrolidinas/normas , Adulto JovemRESUMO
Sleep is a crucial physiological process for our survival and cognitive performance, yet the factors controlling human sleep regulation remain poorly understood. Here, we identified a missense mutation in a G protein-coupled neuropeptide S receptor 1 (NPSR1) that is associated with a natural short sleep phenotype in humans. Mice carrying the homologous mutation exhibited less sleep time despite increased sleep pressure. These animals were also resistant to contextual memory deficits associated with sleep deprivation. In vivo, the mutant receptors showed increased sensitivity to neuropeptide S exogenous activation. These results suggest that the NPS/NPSR1 pathway might play a critical role in regulating human sleep duration and in the link between sleep homeostasis and memory consolidation.
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Consolidação da Memória/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Sono/fisiologia , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Mutação/genética , Reação em Cadeia da Polimerase , Reação em Cadeia da Polimerase em Tempo Real , Receptores Acoplados a Proteínas G/genética , Sono/genéticaRESUMO
Sleep is crucial for our survival, and many diseases are linked to long-term poor sleep quality. Before we can use sleep to enhance our health and performance and alleviate diseases associated with poor sleep, a greater understanding of sleep regulation is necessary. We have identified a mutation in the ß1-adrenergic receptor gene in humans who require fewer hours of sleep than most. In vitro, this mutation leads to decreased protein stability and dampened signaling in response to agonist treatment. In vivo, the mice carrying the same mutation demonstrated short sleep behavior. We found that this receptor is highly expressed in the dorsal pons and that these ADRB1+ neurons are active during rapid eye movement (REM) sleep and wakefulness. Activating these neurons can lead to wakefulness, and the activity of these neurons is affected by the mutation. These results highlight the important role of ß1-adrenergic receptors in sleep/wake regulation.
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Receptores Adrenérgicos beta 1/genética , Sono/genética , Vigília/genética , Animais , Técnicas de Introdução de Genes , Humanos , Camundongos , Mutação , Neurônios/metabolismo , Linhagem , Tegmento Pontino/citologia , Tegmento Pontino/metabolismo , Transtornos do Sono-Vigília/genética , Sono REM/genéticaRESUMO
Many components of the circadian molecular clock are conserved from flies to mammals; however, the role of mammalian Timeless remains ambiguous. Here, we report a mutation in the human TIMELESS (hTIM) gene that causes familial advanced sleep phase (FASP). Tim CRISPR mutant mice exhibit FASP with altered photic entrainment but normal circadian period. We demonstrate that the mutation prevents TIM accumulation in the nucleus and has altered affinity for CRY2, leading to destabilization of PER/CRY complex and a shortened period in nonmature mouse embryonic fibroblasts (MEFs). We conclude that TIM, when excluded from the nucleus, can destabilize the negative regulators of the circadian clock, alter light entrainment, and cause FASP.
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Proteínas de Ciclo Celular/genética , Relógios Circadianos/genética , Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação/genética , Sono/genética , Animais , Linhagem Celular , Fibroblastos/fisiologia , Células HEK293 , Humanos , Luz , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
PURPOSE: Scleral remodeling causes the excessive ocular elongation that underlies myopia. Lysyl oxidase (LOX), a copper-containing amine oxidase, can catalyze collagen and elastin crosslinking. The purpose of this study was to investigate the role of LOX in scleral remodeling in form-deprivation myopia (FDM). METHODS: Seventy-five guinea pigs were randomly divided into five groups as follows: a normal control group, an FDM group, an FDM plus ß-aminopropionitrile (BAPN) group, an FDM plus TGF-ß1 (TGF-ß1) group, and an FDM plus vehicle group. A translucent diffuser was used to induce FDM, and intravitreal injection was used to administer BAPN, TGF-ß1 or vehicle. The scleral LOX and collagen gene and protein levels and the posterior scleral ultrastructure and biomechanics were measured. RESULTS: In the FDM group, both the scleral LOX and collagen gene and protein levels were significantly lower than those in the control eyes. The collagen fibril diameters were significantly decreased in the FDM group compared with the diameters in the control group. A significant decrease in LOX gene and protein expression was observed after BAPN injection, and an increase was observed after TGF-ß1 treatment compared with the levels in the FDM group. Additionally, the scleral collagen fibrils were significantly decreased in the BAPN-treated eyes but increased in the TGF-ß1-treated eyes compared with the FDM eyes. The ultimate stress and Young's modulus of the sclera were lowest in the BAPN group, followed by the FDM group and the TGF-ß1 group. The ultimate strain (%) of the sclera was lowest in the TGF-ß1 group, followed by the FDM group and the BAPN group. CONCLUSION: LOX expression was significantly lowered in myopic sclera. Modulating LOX expression induced a change in both the scleral collagen fibril diameter and the scleral biomechanics. Therefore, LOX may play a key role in the myopia scleral remodeling procedure.
Assuntos
Colágeno Tipo I/metabolismo , Regulação da Expressão Gênica/fisiologia , Miopia/enzimologia , Proteína-Lisina 6-Oxidase/genética , Proteína-Lisina 6-Oxidase/metabolismo , Esclera/fisiologia , Aminopropionitrilo/farmacologia , Animais , Fenômenos Biomecânicos , Western Blotting , Colágeno Tipo I/genética , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Cobaias , Microscopia Eletrônica de Transmissão , Miopia/fisiopatologia , Proteína-Lisina 6-Oxidase/antagonistas & inibidores , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Esclera/ultraestrutura , Privação Sensorial , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
PURPOSE: To investigate the interaction between corneal, internal, and total wavefront aberrations (WAs) and their influential factors during orthokeratology (OK) treatment in Chinese adolescents. METHODS: Thirty teenagers (n = 30 eyes) were enrolled in the study; spherical equivalent refraction (SE), corneal curvature radius (CCR), central corneal thickness (CCT), WAs, and the difference in limbal transverse diameter and OK lens diameter (ΔLLD) were detected before and after one-month OK treatment. Every component of WAs was measured simultaneously by iTrace aberrometer. The influential factors of OK-induced WAs were analyzed. RESULTS: SE and CCT decreased while CCR increased significantly (P < 0.01). Higher-order aberrations (HOAs), Spherical aberrations (SAs), and coma increased significantly (P < 0.01). Corneal horizontal coma (Z31-C) and corneal spherical aberrations (Z40-C) increased (P < 0.01). The HOAs, coma, SAs, Z31-C, Z31-T, Z40-C, and Z40-T were positively correlated with SE and CCR (P < 0.01). Z3-1-C showed negative correlations with (ΔLLD) and positive correlations with SE (P < 0.05). CONCLUSIONS: The increase in OK-induced HOAs is mainly attributed to Z31 and Z40 of cornea. Z3-1 in the internal component showed a compensative effect on the corneal vertical coma. The degree of myopic correction and increase in CCR may be the essential influential factors of the increase in Z31 and Z40. The appropriate size of the OK lens may be helpful to decrease OK-induced vertical coma.
Assuntos
Córnea/cirurgia , Topografia da Córnea/estatística & dados numéricos , Aberrações de Frente de Onda da Córnea , Procedimentos Ortoceratológicos , Adolescente , Criança , Estudos de Coortes , Aberrações de Frente de Onda da Córnea/diagnóstico , Aberrações de Frente de Onda da Córnea/etiologia , Feminino , Humanos , Masculino , Procedimentos Ortoceratológicos/efeitos adversos , Procedimentos Ortoceratológicos/estatística & dados numéricosRESUMO
PURPOSE: To investigate associations between changes in tear film instability and the lipid layer thickness (LLT) and blink pattern after corneal refractive surgery (CRS). METHODS: Forty patients were enrolled in this study. The LLT and blink pattern were evaluated 1 week before and 30 days after CRS using a novel interferometer and an ocular surface disease index (OSDI) questionnaire, and other tear film stability markers were also evaluated. RESULTS: Mean OSDI scores increased from 5.52 to 8.54 (P = 0.016), corneal fluorescence staining scores increased from 0.05 to 0.25 (P = 0.034), first noninvasive tear breakup time (NIBUT-F) decreased from 9.66 to 7.33 seconds (P = 0.014), and average noninvasive tear breakup time (NIBUT-Ave) decreased from 12.32 to 10.26 seconds (P = 0.047) 1 month after CRS. Meanwhile, mean total blink frequency in 20 seconds decreased significantly from 12.62 to 6.31 (P < 0.001); LLT did not change significantly (P = 0.447). The change in NIBUT-Ave was positively correlated with that in LLT (P = 0.003) and negatively correlated with that in the partial blink rate (P = 0.013). The changes in the OSDI questionnaire, NIBUT, LLT, and blink pattern were not different between the laser-assisted in situ keratomileusis and laser-assisted subepithelial keratomileusis groups. CONCLUSIONS: A decrease in tear film stability occurs 1 month after CRS, the change in the blink pattern and unchanged LLT preoperatively and postoperatively suggesting that these parameters play a role in maintaining tear film stability after CRS.
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Piscadela/fisiologia , Córnea/fisiologia , Ceratectomia Subepitelial Assistida por Laser , Ceratomileuse Assistida por Excimer Laser In Situ , Metabolismo dos Lipídeos/fisiologia , Lágrimas/metabolismo , Adolescente , Adulto , Paquimetria Corneana , Feminino , Humanos , Interferometria , Lasers de Excimer/uso terapêutico , Masculino , Inquéritos e Questionários , Adulto JovemRESUMO
Why we sleep remains one of the greatest mysteries in science. In the past few years, great advances have been made to better understand this phenomenon. Human genetics has contributed significantly to this movement, as many features of sleep have been found to be heritable. Discoveries about these genetic variations that affect human sleep will aid us in understanding the underlying mechanism of sleep. Here we summarize recent discoveries about the genetic variations affecting the timing of sleep, duration of sleep and EEG patterns. To conclude, we also discuss some of the sleep-related neurological disorders such as Autism Spectrum Disorder (ASD) and Alzheimer's Disease (AD) and the potential challenges and future directions of human genetics in sleep research.
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Variação Genética , Sono/genética , Eletroencefalografia , Genética Médica/tendências , Humanos , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/fisiopatologia , Pesquisa/tendências , TempoRESUMO
Understanding the mechanism underlying the physiological divergence of species is a long-standing issue in evolutionary biology. The circadian clock is a highly conserved system existing in almost all organisms that regulates a wide range of physiological and behavioral events to adapt to the day-night cycle. Here, the interactions between hCK1ϵ/δ/DBT (Drosophila ortholog of CK1δ/ϵ) and serine-rich (SR) motifs from hPER2 (ortholog of Drosophila per) were reconstructed in a Drosophila circadian system. The results indicated that in Drosophila, the SR mutant form hPER2S662G does not recapitulate the mouse or human mutant phenotype. However, introducing hCK1δ (but not DBT) shortened the circadian period and restored the SR motif function. We found that hCK1δ is catalytically more efficient than DBT in phosphorylating the SR motif, which demonstrates that the evolution of CK1δ activity is required for SR motif modulation. Moreover, an abundance of phosphorylatable SR motifs and the striking emergence of putative SR motifs in vertebrate proteins were observed, which provides further evidence that the correlated evolution between kinase activity and its substrates set the stage for functional diversity in vertebrates. It is possible that such correlated evolution may serve as a biomarker associated with the adaptive benefits of diverse organisms. These results also provide a concrete example of how functional synthesis can be achieved through introducing evolutionary partners in vivo.
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Proteínas CLOCK/metabolismo , Caseína Quinase 1 épsilon/metabolismo , Relógios Circadianos/fisiologia , Drosophila melanogaster/enzimologia , Evolução Molecular , Serina/metabolismo , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Humanos , Camundongos , Fenótipo , Fosforilação , Filogenia , Homologia de Sequência de AminoácidosRESUMO
Purpose: Acanthamoeba keratitis (AK), which is associated with noncompliant use of contact lenses, remains difficult to treat due to delayed diagnosis and paucity of therapeutic agents. Although improvements in activity against Acanthamoeba infection have been achieved in disinfecting solutions for soft contact lenses, such modifications have not been extended to those for special rigid gas permeable (RGP) contact lenses, which are increasingly used for myopia control in children. Phytochemicals present in herbs used for traditional Chinese medicine may be effective as therapeutic or preventive agents. The purpose of this study was to investigate amoebicidal properties of lead phytochemicals of Radix scutellariae alone and in combination with multipurpose (disinfecting) solutions (MPS) for RGP lenses. Methods: Viability of Acanthamoeba castellani and A. polyphaga trophozoites was determined following exposure to four phytochemicals: baicalin, baicalein, wogonoside, and oroxylin A and both alone and in combination with four RGP MPS, using a modified stand-alone technique. Results: As individual agents, wogonoside and oroxylin A showed highest activity against A. castellani and A. polyphaga trophozoites, respectively. For both organisms, the combination of baicalein and oroxylin A was superior. Effectiveness of MPS alone did not exceed 0.27 log reduction, but addition of combined baicalein and oroxylin A resulted in 0.92 and 0.64 log reductions of A. castellani and A. polyphaga, respectively. Conclusions: The combination of baicalein and oroxylin A enhanced the activity of MPS for RGP contact lenses against trophozoites of two pathogens, A. castellani, and A. polyphaga, and offers a potential therapeutic and/or preventative agent for AK.
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Ceratite por Acanthamoeba/prevenção & controle , Acanthamoeba/efeitos dos fármacos , Lentes de Contato Hidrofílicas/parasitologia , Desinfetantes/farmacologia , Desinfecção/métodos , Chumbo/farmacologia , Compostos Fitoquímicos/farmacologia , Ceratite por Acanthamoeba/parasitologia , Animais , Antioxidantes/farmacologia , Soluções para Lentes de Contato/farmacologia , Flavanonas/farmacologia , Flavonoides/farmacologia , NAD(P)H Desidrogenase (Quinona)RESUMO
Many animals display morning and evening bimodal activities in the day/night cycle. However, little is known regarding the potential components involved in the regulation of bimodal behavioral rhythms in mammals. Here, we identified that the zinc finger protein gene Zbtb20 plays a crucial role in the regulation of bimodal activities in mice. Depletion of Zbtb20 in nerve system resulted in the loss of early evening activity, but the increase of morning activity. We found that Zbtb20-deficient mice exhibited a pronounced decrease in the expression of Prokr2 and resembled phenotypes of Prok2 and Prokr2-knockout mice. Injection of adeno-associated virus-double-floxed Prokr2 in suprachiasmatic nucleus could partly restore evening activity in Nestin-Cre; Zbtb20fl/fl (NS-ZB20KO) mice. Furthermore, loss of Zbtb20 in Foxg1 loci, but intact in the suprachiasmatic nucleus, was not responsible for the unimodal activity of NS-ZB20KO mice. Our study provides evidence that ZBTB20-mediated PROKR2 signaling is critical for the evening behavioral rhythms.
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Familial Advanced Sleep Phase (FASP) is a heritable human sleep phenotype characterized by very early sleep and wake times. We identified a missense mutation in the human Cryptochrome 2 (CRY2) gene that co-segregates with FASP in one family. The mutation leads to replacement of an alanine residue at position 260 with a threonine (A260T). In mice, the CRY2 mutation causes a shortened circadian period and reduced phase-shift to early-night light pulse associated with phase-advanced behavioral rhythms in the light-dark cycle. The A260T mutation is located in the phosphate loop of the flavin adenine dinucleotide (FAD) binding domain of CRY2. The mutation alters the conformation of CRY2, increasing its accessibility and affinity for FBXL3 (an E3 ubiquitin ligase), thus promoting its degradation. These results demonstrate that CRY2 stability controlled by FBXL3 plays a key role in the regulation of human sleep wake behavior.
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Criptocromos/genética , Criptocromos/metabolismo , Proteínas F-Box/metabolismo , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Mutação de Sentido Incorreto , Transtornos do Sono do Ritmo Circadiano/genética , Alanina/genética , Substituição de Aminoácidos , Animais , Humanos , Camundongos , Conformação Proteica , Proteólise , Treonina/genética , UbiquitinaçãoRESUMO
BACKGROUND/AIM: There has been increasing evidence of the emergence of antiseptic resistance mediated by quaternary ammonium compound (QAC) resistance genes, which may reduce the efficacy of disinfection. Although the presence of QAC-positive staphylococci has been shown to be elevated in contact lens wearers, the efficacy of multipurpose solutions (MPS) against such isolates has not been determined. This study investigated the efficacy of four MPS for rigid gas permeable (RGP) lenses against staphylococci-harbouring QAC genes. METHODS: Ability to reduce viability by three or more log reductions of four MPS for RGP lenses was tested against 60 disinfectant-resistant gene-positive staphylococci, comprising 38 coagulase-negative staphylococci (CNS) (17 ITALIC! qacA/B, 7 ITALIC! smr, 5 ITALIC! qacH, 9 habouring two or more genes) and 22 ITALIC! Staphylococcus aureus (16 ITALIC! qacA/B, 4 ITALIC! smr, 2 ITALIC! qacA/B+ ITALIC! smr)). 60 gene-negative isolates of staphylococci (30 CNS and 30 ITALIC! S aureus) were used as controls. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these four MPS were determined. RESULTS: Although there was some variation between solutions, all failed to achieve a 3-log reduction in some ITALIC! S aureus and CNS isolates. Strains harbouring disinfectant-resistant genes were significantly less likely to be reduced by 3 logs by three of the solutions. Overall, the MIC and MBC of the four MPS against gene-positive clinical isolates were significantly higher than those of gene-negative isolates. CONCLUSION: The efficacy of MPS solutions for RGP lenses against staphylococci varied. The presence of disinfectant-resistance genes significantly adversely affected disinfecting capacity of RGP solutions.
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Soluções para Lentes de Contato/farmacologia , Lentes de Contato/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Genes MDR/fisiologia , Procedimentos Ortoceratológicos , Staphylococcus aureus/efeitos dos fármacos , Antiporters/genética , Proteínas de Bactérias/genética , Contagem de Colônia Microbiana , Túnica Conjuntiva/microbiologia , Humanos , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana , Compostos de Amônio Quaternário/farmacologia , Proteínas Repressoras/genética , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificaçãoRESUMO
In the core mammalian circadian negative feedback loop, the BMAL1-CLOCK complex activates the transcription of the genes Period (Per) and Cryptochrome (Cry). To close the negative feedback loop, the PER-CRY complex interacts with the BMAL1-CLOCK complex to repress its activity. These two processes are separated temporally to ensure clock function. Here, we show that histone deacetylase 3 (HDAC3) is a critical component of the circadian negative feedback loop by regulating both the activation and repression processes in a deacetylase activity-independent manner. Genetic depletion of Hdac3 results in low-amplitude circadian rhythms and dampened E-box-driven transcription. In subjective morning, HDAC3 is required for the efficient transcriptional activation process by regulating BMAL1 stability. In subjective night, however, HDAC3 blocks FBXL3-mediated CRY1 degradation and strongly promotes BMAL1 and CRY1 association. Therefore, these two opposing but temporally separated roles of HDAC3 in the negative feedback loop provide a mechanism for robust circadian gene expression.
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Relógios Circadianos , Retroalimentação Fisiológica , Histona Desacetilases/metabolismo , Fatores de Transcrição ARNTL/metabolismo , Animais , Criptocromos/metabolismo , Elementos E-Box , Histona Desacetilases/genética , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , ProteóliseRESUMO
PURPOSE: This study observed biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus in contact lens cases and investigated the inhibitory effects of 2,2'-dipyridyl (2DP) and 1,2,3,4,6-penta-O-galloyl-b-D-glucopyranose (PGG). METHODS: Biofilm formation of P. aeruginosa ATCC 9027 and S. aureus ATCC 25923 and ATCC 6538 in contact lens cases was determined for a range of initial inocula and incubation times using crystal violet staining. The effects of 2DP and PGG on biofilm were evaluated alone and in combination by their incorporation into the media at commencement of incubation. RESULTS: At 24 hours, biofilm production was related to initial concentration. However, with extended incubation, higher initial concentrations affected formation in S. aureus. Presence of 312 µM 2DP significantly inhibited P. aeruginosa biofilm formation, but had little effect on that of S. aureus. In contrast, PGG (50 µM) inhibited S. aureus biofilm formation, but had much less effect on that of P. aeruginosa. Combination of the agents effectively inhibited biofilm formation of all three organisms throughout a week-long incubation period with OD levels barely exceeding cell-free controls. CONCLUSIONS: Biofilm formation of P. aeruginosa could be prevented by 2DP, while biofilm formation of S. aureus was inhibited by PGG. However, combining these agents showed better inhibition of biofilm production than use of either agent alone on both species. This combination may be useful in prevention of biofilm in contact lens cases, thereby reducing infection risk due to poor compliance with lens case cleaning and replacement. Further work is needed to confirm compatibility with multipurpose solutions and investigate cytotoxicity to ocular tissues.