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1.
Water Res ; 258: 121781, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38761597

RESUMO

Biogas slurry from anaerobic digestion is rich in nutrients but has not been fully utilized due to a high content of suspended solids (SS) causing clogging during agricultural irrigation. This study aimed to evaluate the performance of a novel chitosan and polyferric sulfate (CTS-PFS) composite coagulant for simultaneous flocculation and floatation to enhance SS removal while preserving nutrients in biogas slurry. Orthogonal method was used for experimental design to determine the optimal synthesis and operational conditions of CTS-PFS. Results show that CTS-PFS outperformed individual CTS and PFS coagulant in terms of SS removal and nutrient (nitrogen, phosphorus, and potassium) preservation. Compared to individual CTS and PFS coagulation, the combination of CTS and PFS at the mass ratio of 1:6 showed significantly higher performance by 41.5 % increase in SS removal and 5.2 % reduction in nutrient loss. The improved performance of CTS-PFS was attributed to its formation of polynuclear hydroxyl complexes with ferric oxide groups (e.g. Fe-OH, Fe-O-Fe, Fe-OH-Fe and COO-Fe) to strengthen charge neutralization and adsorption bridging. Data from this study further confirm that CTS-PFS enhanced the removal of small suspended particles and dissolved organic matter in the molecular weight range of 0.4-2.0 kDa and preserved ammonia and potassium better in biogas slurry. Bubbles were generated as hydrogen ions from coagulant hydrolysis interacted with bicarbonate and carbonate in biogas slurry for removing the produced flocs by floatation. Floc flotation was more effective in CTS-PFS coagulation due to the significant production of uniform bubbles, evidenced by the reduction in the viscosity of biogas slurry.


Assuntos
Biocombustíveis , Quitosana , Floculação , Quitosana/química , Compostos Férricos/química , Eliminação de Resíduos Líquidos/métodos , Fósforo/química , Nitrogênio/química
2.
Int Immunopharmacol ; 132: 111856, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38537537

RESUMO

BACKGROUND AND AIMS: Inflammation and atherosclerosis (AS) are closely associated to Secreted Protein Acidic and Rich in Cysteine (SPARC) and its related factors. This study attempted to define the role and the potential mechanism of SPARC and its related factors in ameliorating hyperlipidemia and AS by aerobic exercise intervention. METHODS: The AS rat model was established with a high-fat diet plus vitamin D3 intraperitoneal injection. Treadmill exercises training (5 days/week at 14 m/min for 60 min/day) for 6 weeks was carried out for AS rat intervention method. Western blotting and qRT-PCR were used to analyze the mRNA and protein expression of SPARC and its related factors, respectively. H&E staining was applied to evaluate the morphological changes and inflammation damage. Von Kossa staining was used to measure the degree of vascular calcification. Fluorescence immunohistochemistry staining was used to detect the expression and distribution of SPARC signal molecules. RESULTS: SPARC was highly expressed and co-localization with the smooth muscle marker α-SMC in the AS rat. And its downstream factors, NF-κB, Caspase-1, IL-1ß and IL-18 were upregulated (P < 0.05 or P < 0.01), FNDC5 expression was downregulated in AS rat model. However, slight declined body weight, delayed AS progression, decreased hyperlipidemia and favorable morphology of skeletal muscle and blood vessels have been detected in AS rat with aerobic exercise intervention. Moreover, the expression of SPARC and its downstream factors were decreased (P < 0.05 or P < 0.01), while elevated the expression of FNDC5 (P < 0.01) was observed after aerobic exercise intervention. CONCLUSIONS: This study suggested that aerobic exercise ameliorated hyperlipidemia and AS by effectively inhibiting SPARC signal, and vascular smooth muscle cells may contribute greatly to the protection of AS.


Assuntos
Aterosclerose , Dieta Hiperlipídica , Osteonectina , Condicionamento Físico Animal , Ratos Sprague-Dawley , Animais , Osteonectina/metabolismo , Osteonectina/genética , Aterosclerose/terapia , Aterosclerose/metabolismo , Masculino , Ratos , Transdução de Sinais , Modelos Animais de Doenças , Hiperlipidemias/terapia , Hiperlipidemias/metabolismo , Colecalciferol/metabolismo
3.
Soc Cogn Affect Neurosci ; 19(1)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38123451

RESUMO

The ability to accurately decode others' facial expressions is essential for successful social interaction. Previous theories suggest that aspects of parental emotionality-the frequency, persistence and intensity of parents' own emotions-can influence children's emotion perception. Through a combination of mechanisms, parental emotionality may shape how children's brains specialize to respond to emotional expressions, but empirical data are lacking. The present study provides a direct empirical test of the relation between the intensity, persistence and frequency of parents' own emotions and children's neural responses to perceiving emotional expressions. Event-related potentials (ERPs) were recorded as typically developing 3- to 5-year-old children (final Ns = 59 and 50) passively viewed faces expressing different emotional valences (happy, angry and fearful) at full and reduced intensity (100% intense expression and 40% intense expression). We examined relations between parental emotionality and children's mean amplitude ERP N170 and negative central responses. The findings demonstrate a clear relation between parental emotionality and children's neural responses (in the N170 mean amplitude and latency) to emotional expressions and suggest that parents may influence children's emotion-processing neural circuitry.


Assuntos
Emoções , Pais , Humanos , Pré-Escolar , Emoções/fisiologia , Pais/psicologia , Ira , Medo , Encéfalo , Potenciais Evocados/fisiologia , Expressão Facial
4.
Environ Pollut ; 331(Pt 2): 121945, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37268217

RESUMO

This study mapped the fate of antibiotics in a swine farm with integrated waste treatment including anoxic stabilization, fixed-film anaerobic digestion, anoxic-oxic (A/O), and composting. Results show the prevalent and consistent occurrence of 12 antibiotics in swine waste. Mass balance of these antibiotics was calculated to track their flow and evaluate their removal by different treatment units. The integrated treatment train could effectively reduce antibiotic loading to the environment by 90% (measured as combined mass of all antibiotic residues). Within the treatment train, anoxic stabilization as the initial treatment step, accounted for the highest contribution (43%) to overall antibiotic elimination. Results also show that aerobic was more effective than anaerobic regarding antibiotic degradation. Composting accounted for an additional of 31% removal of antibiotics while anaerobic digestion contributed to 15%. After treatment, antibiotic residues in the treated effluent and composted materials were 2 and 8% of the initial antibiotic loading in raw swine waste, respectively. Ecological risk assessment showed negligible or low risk quotient associated with most individual antibiotics released into the aquatic environment or soil from swine farming. Nevertheless, antibiotic residues in treated water and composted materials together showed significant ecological risk to water and soil organisms. Thus, further work to improve treatment performance or develop new technologies is necessary to reduce the impact of antibiotics from swine farming.


Assuntos
Antibacterianos , Compostagem , Animais , Suínos , Agricultura , Fazendas , Solo
5.
Nat Cancer ; 4(7): 984-1000, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37365326

RESUMO

Molecular routes to metastatic dissemination are critical determinants of aggressive cancers. Through in vivo CRISPR-Cas9 genome editing, we generated somatic mosaic genetically engineered models that faithfully recapitulate metastatic renal tumors. Disruption of 9p21 locus is an evolutionary driver to systemic disease through the rapid acquisition of complex karyotypes in cancer cells. Cross-species analysis revealed that recurrent patterns of copy number variations, including 21q loss and dysregulation of the interferon pathway, are major drivers of metastatic potential. In vitro and in vivo genomic engineering, leveraging loss-of-function studies, along with a model of partial trisomy of chromosome 21q, demonstrated a dosage-dependent effect of the interferon receptor genes cluster as an adaptive mechanism to deleterious chromosomal instability in metastatic progression. This work provides critical knowledge on drivers of renal cell carcinoma progression and defines the primary role of interferon signaling in constraining the propagation of aneuploid clones in cancer evolution.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/genética , Variações do Número de Cópias de DNA/genética , Instabilidade Cromossômica/genética , Aneuploidia , Neoplasias Renais/genética
6.
Materials (Basel) ; 16(9)2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37176414

RESUMO

Superhydrophobic coatings with excellent water-repellent properties imply a wide range of application areas. However, improvements are needed in terms of stability and complex processing procedures. In the present study, a superhydrophobic coating on Al sheets was prepared by mixing hexadecyltrimethoxysilane (HDTMS)-modified SiO2 nanoparticles and acid-catalyzed silica sols (HD-SiO2/SiO2 Sol) with polydimethylsiloxane (PDMS) binder. The HD-SiO2 nanoparticles and acid-catalyzed silica sol (SiO2 sol) form a binary graded micro-nanostructure, providing excellent superhydrophobicity (Water Contact Angle = 158.5°, Sliding angle = 0°). Superhydrophobic coatings with excellent water-repellent properties have potential for corrosion prevention. However the commonly used organic resins have poor chemical and mechanical properties. In the present study, the results of outdoor exposure for 30 days, immersion in acid and alkaline solutions for 24 h, grit abrasion, and water impact experiments, respectively, showed that the prepared superhydrophobic coating has good wear resistance. The integrated superhydrophobic coating on the Al sheets exhibited good corrosion inhibition with an efficiency (η) of 98.9%, which is much higher than that of the uncoated sheets. The present study provides a promising approach for producing stable superhydrophobic coatings at a low cost, with the potential to supplant conventional organic resin anti-corrosion coatings.

7.
Materials (Basel) ; 16(10)2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37241477

RESUMO

Polycarbonate (PC) with high transmittance, stable mechanical performance and environmental resistance is crucial for practical applications. In this work, we report a method for the preparation of a robust antireflective (AR) coating by a simple dip-coating process of a mixed ethanol suspension consisting of tetraethoxysilane (TEOS) base-catalyzed silica nanoparticles (SNs) and acid-catalyzed silica sol (ACSS). ACSS greatly improved the adhesion and durability of the coating, and the AR coating exhibited high transmittance and mechanical stability. Water and hexamethyldisilazane (HMDS) vapor treatment were further employed to improve the hydrophobicity of the AR coating. The as-prepared coating exhibited excellent antireflective properties, with an average transmittance of 96.06% in the wavelength range of 400 to 1000 nm, which is 7.55% higher than the bare PC substrate. After sand and water droplet impact tests, the AR coating still maintained enhanced transmittance and hydrophobicity. Our method shows a potential application for the preparation of hydrophobic AR coatings on a PC substrate.

8.
Materials (Basel) ; 16(8)2023 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-37109973

RESUMO

To improve the efficacy of polymer-based substrate hybrid coatings, it is essential to simultaneously optimize mechanical strength and preserve the optical properties. In this study, a mixture of zirconium oxide (ZrO2) sol and methyltriethoxysilane modified silica (SiO2) sol-gel was dip-coated onto polycarbonate (PC) substrates to form zirconia-enhanced SiO2 hybrid coatings. Additionally, a solution containing 1H, 1H, 2H, and 2H-perfluorooctyl trichlorosilane (PFTS) was employed for surface modification. The results show that the ZrO2-SiO2 hybrid coating enhanced the mechanical strength and transmittance. The average transmittance of the coated PC reached up to 93.9% (400-800 nm), while the peak transmittance reached up to 95.1% at 700 nm. SEM images and AFM morphologies demonstrate that the ZrO2 and SiO2 nanoparticles were evenly distributed, and a flat coating was observed on the PC substrate. The PFTS-modified ZrO2-SiO2 hybrid coating also exhibited good hydrophobicity (WCA, 113°). As an antireflective coating on PC, with self-cleaning capability, the proposed coating has application prospects in optical lenses and automotive windows.

9.
J Transl Med ; 20(1): 426, 2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36138468

RESUMO

BACKGROUND: Long non-coding RNAs (lncRNAs) are closely related to the occurrence and development of cancer. Abnormally expressed lncRNA can be used as a diagnostic marker for cancer. In this study, we aim to investigate the clinical significance of MIR99AHG expression in lung adenocarcinoma (LUAD), and its biological roles in LUAD progression. METHODS: The relative expression of MIR99AHG in LUAD tissues and cell lines was analyzed using public databases and RT-qPCR. The biological functions of MIR99AHG were investigated using a loss-of-function approach. The effect of MIR99AHG on lung fibrosis was assessed by scratch assay, invasion assay and lung fibrosis rat model. FISH, luciferase reporter assay and immunofluorescence were performed to elucidate the underlying molecular mechanisms. RESULTS: LncRNA MIR99AHG expression level was downregulated in LUAD tissues and cell lines. Low MIR99AHG levels were associated with poorer patient overall survival. Functional analysis showed that MIR99AHG is associated with the LUAD malignant phenotype in vitro and in vivo. Further mechanistic studies showed that, MIR99AHG functions as a competitive endogenous RNA (ceRNA) to antagonize miR-136-5p-mediated ubiquitin specific protease 4 (USP4) degradation, thereby unregulated the expression of angiotensin-converting enzyme 2 (ACE2), a downstream target gene of USP4, which in turn affected alveolar type II epithelial cell fibrosis and epithelial-mesenchymal transition (EMT). In summary, the MIR99AHG/miR-136-5p/USP4/ACE2 signalling axis regulates lung fibrosis and EMT, thus inhibiting LUAD progression. CONCLUSION: This study showed that downregulated MIR99AHG leads to the development of pulmonary fibrosis. Therefore, overexpression of MIR99AHG may provide a new approach to preventing LUAD progression.


Assuntos
Adenocarcinoma , Neoplasias Pulmonares , MicroRNAs , Fibrose Pulmonar , RNA Longo não Codificante , Adenocarcinoma/genética , Enzima de Conversão de Angiotensina 2 , Animais , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , Fibrose Pulmonar/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Ratos , Proteases Específicas de Ubiquitina/genética , Proteases Específicas de Ubiquitina/metabolismo
10.
J Am Soc Nephrol ; 28(11): 3278-3290, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28768710

RESUMO

In damaged kidneys, increased extracellular matrix (ECM) and tissue stiffness stimulate kidney fibrosis through incompletely characterized molecular mechanisms. The transcriptional coactivators yes-associated protein (Yap) and transcriptional coactivator with PDZ-binding motif (Taz) function as mechanosensors in cancer cells and have been implicated in the regulation of myofibroblasts in the kidney. We hypothesized that the development of kidney fibrosis depends on Yap-induced activation and proliferation of kidney fibroblasts. In mice, Yap expression increased in renal fibroblasts after unilateral ureteral obstruction (UUO), in association with worsening of interstitial fibrosis. In cultured fibroblasts, inhibition of Yap/Taz signaling blocked TGF-ß1-induced fibroblast-to-myofibroblast transformation and ECM production, whereas constitutive activation of Yap promoted fibroblast transformation and ECM production even in the absence of TGF-ß1. Moreover, in the absence of TGF-ß1, fibroblasts seeded on a stiffened ECM transformed into myofibroblasts in a process dependent on the activation of Yap. In mice with UUO, the Yap inhibitor verteporfin reduced interstitial fibrosis. Furthermore, Gli1+ cell-specific knockout of Yap/Taz in mice suppressed UUO-induced ECM deposition, myofibroblast accumulation, and interstitial fibrosis. In a UUO-release model, induction of Gli1+ cell-specific Yap/Taz knockout partially reversed the development of interstitial fibrosis. Thus, in the kidney, Yap is a tissue mechanosensor that can be activated by ECM and transforms fibroblasts into myofibroblasts; the interaction of Yap/Taz and ECM forms a feed-forward loop resulting in kidney fibrosis. Identifying mechanisms that interrupt this profibrotic cycle could lead to the development of anti-fibrosis therapy.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Rim/patologia , Miofibroblastos , Fosfoproteínas/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas de Ciclo Celular , Matriz Extracelular , Fibroblastos/fisiologia , Fibrose/etiologia , Deleção de Genes , Masculino , Camundongos , Miofibroblastos/metabolismo , Fosfoproteínas/genética , Transativadores , Obstrução Ureteral/patologia , Proteínas de Sinalização YAP , Proteína GLI1 em Dedos de Zinco/biossíntese
11.
J Am Soc Nephrol ; 27(9): 2797-808, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26880799

RESUMO

Muscle proteolysis in CKD is stimulated when the ubiquitin-proteasome system is activated. Serum glucocorticoid-regulated kinase 1 (SGK-1) is involved in skeletal muscle homeostasis, but the role of this protein in CKD-induced muscle wasting is unknown. We found that, compared with muscles from healthy controls, muscles from patients and mice with CKD express low levels of SGK-1. In mice, SGK-1-knockout (SGK-1-KO) induced muscle loss that correlated with increased expression of ubiquitin E3 ligases known to facilitate protein degradation by the ubiquitin-proteasome, and CKD substantially aggravated this response. SGK-1-KO also altered the phosphorylation levels of transcription factors FoxO3a and Smad2/3. In C2C12 muscle cells, expression of dominant negative FoxO3a or knockdown of Smad2/3 suppressed the upregulation of E3 ligases induced by loss of SGK-1. Additionally, SGK-1 overexpression increased the level of phosphorylated N-myc downstream-regulated gene 1 protein, which directly interacted with and suppressed the phosphorylation of Smad2/3. Overexpression of SGK-1 in wild-type mice with CKD had similar effects on the phosphorylation of FoxO3a and Smad2/3 and prevented CKD-induced muscle atrophy. Finally, mechanical stretch of C2C12 muscle cells or treadmill running of wild-type mice with CKD stimulated SGK-1 production, and treadmill running inhibited proteolysis in muscle. These protective responses were absent in SGK-1-KO mice. Thus, SGK-1 could be a mechanical sensor that mediates exercise-induced improvement in muscle wasting stimulated by CKD.


Assuntos
Proteína Forkhead Box O3/fisiologia , Proteínas Imediatamente Precoces/fisiologia , Atrofia Muscular/enzimologia , Atrofia Muscular/etiologia , Proteínas Serina-Treonina Quinases/fisiologia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/enzimologia , Proteína Smad2/fisiologia , Proteína Smad3/fisiologia , Animais , Camundongos
12.
Proc Natl Acad Sci U S A ; 111(21): 7831-6, 2014 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-24821794

RESUMO

In Drosophila melanogaster, the male-specific pheromone cVA (11-cis-vaccenyl acetate) functions as a sex-specific social cue. However, our understanding of the molecular mechanisms underlying cVA pheromone transduction and its regulation are incomplete. Using a genetic screen combined with an electrophysiological assay to monitor pheromone-evoked activity in the cVA-sensing Or67d neurons, we identified an olfactory sensitivity factor encoded by the dATP8B gene, the Drosophila homolog of mammalian ATP8B. dATP8B is expressed in all olfactory neurons that express Orco, the odorant receptor coreceptor, and the odorant responses in most Orco-expressing neurons are reduced. Or67d neurons are severely affected, with strongly impaired cVA-induced responses and lacking spontaneous spiking in the mutants. The dATP8B locus encodes a member of the P4-type ATPase family thought to flip aminophospholipids such as phosphatidylserine and phosphatidylethanolamine from one membrane leaflet to the other. dATP8B protein is concentrated in the cilia of olfactory neuron dendrites, the site of odorant transduction. Focusing on Or67d neuron function, we show that Or67d receptors are mislocalized in dATP8B mutants and that cVA responses can be restored to dATP8B mutants by misexpressing a wild-type dATP8B rescuing transgene, by expressing a vertebrate P4-type ATPase member in the pheromone-sensing neurons or by overexpressing Or67d receptor subunits. These findings reveal an unexpected role for lipid translocation in olfactory receptor expression and sensitivity to volatile odorants.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Ácidos Oleicos/metabolismo , Feromônios/metabolismo , Proteínas de Transferência de Fosfolipídeos/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores Odorantes/metabolismo , Olfato/fisiologia , Animais , Sequência de Bases , Primers do DNA/genética , Proteínas de Drosophila/genética , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Dados de Sequência Molecular , Proteínas de Transferência de Fosfolipídeos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
13.
Mol Neurodegener ; 7: 10, 2012 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-22443542

RESUMO

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is progressive neurodegenerative disease characterized by the loss of motor function. Several ALS genes have been identified as their mutations can lead to familial ALS, including the recently reported RNA-binding protein fused in sarcoma (Fus). However, it is not clear how mutations of Fus lead to motor neuron degeneration in ALS. In this study, we present a Drosophila model to examine the toxicity of Fus, its Drosophila orthologue Cabeza (Caz), and the ALS-related Fus mutants. RESULTS: Our results show that the expression of wild-type Fus/Caz or FusR521G induced progressive toxicity in multiple tissues of the transgenic flies in a dose- and age-dependent manner. The expression of Fus, Caz, or FusR521G in motor neurons significantly impaired the locomotive ability of fly larvae and adults. The presynaptic structures in neuromuscular junctions were disrupted and motor neurons in the ventral nerve cord (VNC) were disorganized and underwent apoptosis. Surprisingly, the interruption of Fus nuclear localization by either deleting its nuclear localization sequence (NLS) or adding a nuclear export signal (NES) blocked Fus toxicity. Moreover, we discovered that the loss of caz in Drosophila led to severe growth defects in the eyes and VNCs, caused locomotive disability and NMJ disruption, but did not induce apoptotic cell death. CONCLUSIONS: These data demonstrate that the overexpression of Fus/Caz causes in vivo toxicity by disrupting neuromuscular junctions (NMJs) and inducing apoptosis in motor neurons. In addition, the nuclear localization of Fus is essential for Fus to induce toxicity. Our findings also suggest that Fus overexpression and gene deletion can cause similar degenerative phenotypes but the underlying mechanisms are likely different.


Assuntos
Esclerose Lateral Amiotrófica/genética , Apoptose/fisiologia , Proteínas de Drosophila/genética , Neurônios Motores/patologia , Junção Neuromuscular/ultraestrutura , Proteína FUS de Ligação a RNA/genética , Proteínas de Ligação a RNA/genética , Fator de Transcrição TFIID/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Humanos , Neurônios Motores/metabolismo , Junção Neuromuscular/genética , Junção Neuromuscular/metabolismo , Proteína FUS de Ligação a RNA/metabolismo , Proteína FUS de Ligação a RNA/fisiologia , Proteínas de Ligação a RNA/metabolismo , Fator de Transcrição TFIID/metabolismo
14.
PLoS Biol ; 10(1): e1001238, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22253573

RESUMO

The seven transmembrane protein Smoothened (Smo) is a critical component of the Hedgehog (Hh) signaling pathway and is regulated by phosphorylation, dimerization, and cell-surface accumulation upon Hh stimulation. However, it is not clear how Hh regulates Smo accumulation on the cell surface or how Hh regulates the intracellular trafficking of Smo. In addition, little is known about whether ubiquitination is involved in Smo regulation. In this study, we demonstrate that Smo is multi-monoubiquitinated and that Smo ubiquitination is inhibited by Hh and by phosphorylation. Using an in vivo RNAi screen, we identified ubiquitin-specific protease 8 (USP8) as a deubiquitinase that down-regulates Smo ubiquitination. Inactivation of USP8 increases Smo ubiquitination and attenuates Hh-induced Smo accumulation, leading to decreased Hh signaling activity. Moreover, overexpression of USP8 prevents Smo ubiquitination and elevates Smo accumulation, leading to increased Hh signaling activity. Mechanistically, we show that Hh promotes the interaction of USP8 with Smo aa625-753, which covers the three PKA and CK1 phosphorylation clusters. Finally, USP8 promotes the accumulation of Smo at the cell surface and prevents localization to the early endosomes, presumably by deubiquitinating Smo. Our studies identify USP8 as a positive regulator in Hh signaling by down-regulating Smo ubiquitination and thereby mediating Smo intracellular trafficking.


Assuntos
Endopeptidases/fisiologia , Complexos Endossomais de Distribuição Requeridos para Transporte/fisiologia , Receptores Acoplados a Proteínas G/metabolismo , Ubiquitina Tiolesterase/fisiologia , Animais , Drosophila , Endopeptidases/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Células HEK293 , Humanos , Camundongos , Modelos Biológicos , Células NIH 3T3 , Transporte Proteico/genética , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Receptor Smoothened , Frações Subcelulares/metabolismo , Distribuição Tecidual , Transfecção , Ubiquitina Tiolesterase/genética , Ubiquitinação/genética
15.
J Biol Chem ; 285(48): 37218-26, 2010 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-20876583

RESUMO

Casein kinase 2 (CK2) is a typical serine/threonine kinase consisting of α and ß subunits and has been implicated in many cellular and developmental processes. In this study, we demonstrate that CK2 is a positive regulator of the Hedgehog (Hh) signal transduction pathway. We found that inactivation of CK2 by CK2ß RNAi enhances the loss-of-Hh wing phenotype induced by a dominant negative form of Smoothened (Smo). CK2ß RNAi attenuates Hh-induced Smo accumulation and down-regulates Hh target gene expression, whereas increasing CK2 activity by coexpressing CK2α and CK2ß increases Smo accumulation and induces ectopic Hh target gene expression. We identified the serine residues in Smo that can be phosphorylated by CK2 in vitro. Mutating these serine residues attenuates the ability of Smo to transduce high level Hh signaling activity in vivo. Furthermore, we found that CK2 plays an additional positive role downstream of Smo by regulating the stability of full-length Cubitus interruptus (Ci). CK2ß RNAi promotes Ci degradation whereas coexpressing CK2α and CK2ß increases the half-life of Ci. We showed that CK2 prevents Ci ubiquitination and degradation by the proteasome. Thus, CK2 promotes Hh signaling activity by regulating multiple pathway components.


Assuntos
Caseína Quinase II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas Hedgehog/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Animais , Caseína Quinase II/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/química , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Regulação da Expressão Gênica , Proteínas Hedgehog/genética , Estabilidade Proteica , Receptores Acoplados a Proteínas G/genética , Receptor Smoothened , Fatores de Transcrição/química , Fatores de Transcrição/genética
16.
Nature ; 431(7010): 869-73, 2004 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-15483616

RESUMO

In Drosophila, a 'clock' situated in the brain controls circadian rhythms of locomotor activity. This clock relies on several groups of neurons that express the Period (PER) protein, including the ventral lateral neurons (LN(v)s), which express the Pigment-dispersing factor (PDF) neuropeptide, and the PDF-negative dorsal lateral neurons (LN(d)s). In normal cycles of day and night, adult flies exhibit morning and evening peaks of activity; however, the contribution of the different clock neurons to the rest-activity pattern remains unknown. Here, we have used targeted expression of PER to restore the clock function of specific subsets of lateral neurons in arrhythmic per(0) mutant flies. We show that PER expression restricted to the LN(v)s only restores the morning activity, whereas expression of PER in both the LN(v)s and LN(d)s also restores the evening activity. This provides the first neuronal bases for 'morning' and 'evening' oscillators in the Drosophila brain. Furthermore, we show that the LN(v)s alone can generate 24 h activity rhythms in constant darkness, indicating that the morning oscillator is sufficient to drive the circadian system.


Assuntos
Relógios Biológicos/fisiologia , Encéfalo/citologia , Encéfalo/fisiologia , Ritmo Circadiano/fisiologia , Drosophila melanogaster/fisiologia , Atividade Motora/fisiologia , Neurônios/fisiologia , Animais , Comportamento Animal/fisiologia , Comportamento Animal/efeitos da radiação , Relógios Biológicos/genética , Relógios Biológicos/efeitos da radiação , Encéfalo/efeitos da radiação , Ritmo Circadiano/genética , Ritmo Circadiano/efeitos da radiação , Escuridão , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/efeitos da radiação , Expressão Gênica , Luz , Atividade Motora/genética , Atividade Motora/efeitos da radiação , Neurônios/efeitos da radiação , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Circadianas Period
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