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1.
Proc Natl Acad Sci U S A ; 119(37): e2203557119, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36067312

RESUMO

Developmental dysplasia of the hip (DDH) is one of the most common congenital skeletal malformations; however, its etiology remains unclear. Here, we conducted whole-exome sequencing in eight DDH families followed by targeted sequencing of 68 sporadic DDH patients. We identified likely pathogenic variants in the LRP1 (low-density lipoprotein receptor-related protein 1) gene in two families and seven unrelated patients. All patients harboring the LRP1 variants presented a typical DDH phenotype. The heterozygous Lrp1 knockout (KO) mouse (Lrp1+/-) showed phenotypes recapitulating the human DDH phenotypes, indicating Lrp1 loss of function causes DDH. Lrp1 knockin mice with a missense variant corresponding to a human variant identified in DDH (Lrp1R1783W) also presented DDH phenotypes, which were milder in heterozygotes and severer in homozygotes than those of the Lrp1 KO mouse. The timing of triradiate cartilage development was brought forward 1 or 2 wk earlier in the LRP-deficient mice, which leads to malformation of the acetabulum and femoral head. Furthermore, Lrp1 deficiency caused a significant decrease of chondrogenic ability in vitro. During the chondrogenic induction of mice bone marrow stem cells and ATDC5 (an inducible chondrogenic cell line), Lrp1 deficiency caused decreased autophagy levels with significant ß-catenin up-regulation and suppression of chondrocyte marker genes. The expression of chondrocyte markers was rescued by PNU-74654 (a ß-catenin antagonist) in an shRNA-Lrp1-expressed ATDC5 cell. Our study reveals a critical role of LRP1 in the etiology and pathogenesis of DDH, opening an avenue for its treatment.


Assuntos
Autofagia , Condrócitos , Displasia do Desenvolvimento do Quadril , Heterozigoto , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Animais , Autofagia/genética , Condrócitos/metabolismo , Condrócitos/patologia , Displasia do Desenvolvimento do Quadril/genética , Displasia do Desenvolvimento do Quadril/patologia , Humanos , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Camundongos , Camundongos Knockout , beta Catenina/metabolismo
2.
Neurochem Res ; 49(6): 1592-1602, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38305960

RESUMO

In the present study, sulfated polysaccharides were obtained by digestion of Sargassum horneri and preparation with enzyme-assisted extraction using three food-grade enzymes, and their anti- Alzheimer's activities were investigated. The results demonstrated that the crude sulfated polysaccharides extracted using AMGSP, CSP and VSP dose-dependently (25-100 µg·mL- 1) raised the spontaneous alternating manner (%) in the Y maze experiment of mice and reduced the escape latency time in Morris maze test. AMGSP, CSP and VSP also exhibited good anti-AChE and moderate anti-BuChE activities. CSP displayed the best inhibitory efficacy against AChE. with IC50 values of 9.77 µM. And, CSP also exhibited good inhibitory selectivity of AChE over BuChE. Next, CSP of the best active crude extract was separated by the preparation type high performance liquid phase to obtain the sulphated fucooligosaccharide section: SFcup (→3-α-L-fucp(2-SO3-)-1→4-α-L-fucp(2,3-SO3-)-1→section), SFcup showed a best inhibitory efficacy against AChE with IC50 values of 4.03 µM. The kinetic research showed that SFcup inhibited AChE through dual binding sites. Moreover, the molecular docking of SFcup at the AChE active site was in accordance with the acquired pharmacological results.


Assuntos
Acetilcolinesterase , Doença de Alzheimer , Inibidores da Colinesterase , Simulação de Acoplamento Molecular , Oligossacarídeos , Sargassum , Sargassum/química , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/química , Inibidores da Colinesterase/uso terapêutico , Camundongos , Acetilcolinesterase/metabolismo , Oligossacarídeos/farmacologia , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Masculino , Sulfatos/química , Sulfatos/farmacologia , Butirilcolinesterase/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Polissacarídeos/farmacologia , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Relação Dose-Resposta a Droga
3.
Cerebrovasc Dis ; : 1-13, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38688248

RESUMO

INTRODUCTION: This study aimed to elucidate the mechanisms underlying endothelial injury in the context of intracranial aneurysm formation and development, which are associated with vascular endothelial injury caused by hemodynamic abnormalities. Specifically, we focus on the involvement of PKCα, an intracellular signaling transmitter closely linked to vascular diseases, and its role in activating MAPK. Additionally, we investigate the protective effects of PPARγ, a vasculoprotective factor known to attenuate vascular injury by mitigating the inflammatory response in the vessel wall. METHODS: The study employs a modified T-chamber to replicate fluid flow conditions at the artery bifurcation, allowing us to assess wall shear stress effects on human umbilical vein endothelial cells in vitro. Through experimental manipulations involving PKCα knockdown and Ca2+ and MAPK inhibitors, we evaluated the phosphorylation status of PKCα, NF-κB, ERK5, ERK1/2, JNK1/2/3, and P38, as well as the expression levels of PPARγ, NF-κB, and MMP2 via Western blot analysis. The cellular localization of phosphorylated NF-κB was determined using immunofluorescence. RESULTS: Our results showed that impinging flow resulted in the activation of PKCα, followed by the phosphorylation of ERK5, ERK1/2, and JNK1/2/3, leading to a decrease in PPARγ expression, an increase in the expression of NF-κB and MMP2, and the induction of apoptotic injury. Inhibition of PKCα activation or knockdown of PKCα using shRNA leads to a suppression of ERK5, ERK1/2, JNK1/2/3, and P38 phosphorylation, an elevation in PPARγ expression, and a reduction in NF-κB and MMP2 expression, alleviated apoptotic injury. Furthermore, we observe that the regulation of PPARγ, NF-κB, and MMP2 expression is influenced by ERK5 and ERK1/2 phosphorylation, and activation of PPARγ effectively counteracts the elevated expression of NF-κB and MMP2. CONCLUSION: Our findings suggest that the PKCα/ERK/PPARγ pathway plays a crucial role in mediating endothelial injury under conditions of impinging flow, with potential implications for vascular diseases and intracranial aneurysm development.

4.
Appl Microbiol Biotechnol ; 108(1): 193, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38308716

RESUMO

The microbiological diagnosis of infection for hematological malignancy patients receiving chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients relies primarily on standard microbial culture, especially blood culture, which has many shortcomings, such as having low positive rates, being time-consuming and having a limited pathogenic spectrum. In this prospective observational self-controlled test accuracy study, blood, cerebrospinal fluid (CSF), and bronchoalveolar lavage fluid (BALF) samples were collected from chemotherapy or allo-HSCT patients with clinical symptoms of infections who were hospitalized at Peking University First Hospital. Possible pathogens were detected by the method based on recombinant mannan-binding lectin (MBL) magnetic bead enrichment (M1 method) and simultaneously by a standard method. The analytical sensitivity of M1 method was close to that of standard culture method. Besides, the turn-around time of M1-method was significantly shorter than that of standard culture method. Moreover, the M1 method also added diagnostic value through the detection of some clinically relevant microbes missed by the standard method. M1 method could significantly increase the detection efficiency of pathogens (including bacteria and fungi) in immunocompromised patients. KEY POINTS: • The detection results of M1-method had a high coincidence rate with that of standard method • M1 method detected many pathogens which had not been found by standard clinic method.


Assuntos
Lectina de Ligação a Manose , Humanos , Líquido da Lavagem Broncoalveolar , Bactérias , Hospedeiro Imunocomprometido , Fenômenos Magnéticos , Sequenciamento de Nucleotídeos em Larga Escala
5.
Biochem Biophys Res Commun ; 679: 110-115, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37677979

RESUMO

The peptide hormone ghrelin (an agonist) and LEAP2 (an antagonist) play important functions in energy metabolism via their receptor GHSR, an A-class G protein-coupled receptor. Ghrelin, LEAP2, and GHSR are widely present from fishes to mammals. However, our recent study suggested that fish GHSRs have different binding properties to ghrelin: a GHSR from the lobe-finned fish Latimeria chalumnae (coelacanth) is efficiently activated by ghrelin, but GHSRs from the ray-finned fish Danio rerio (zebrafish) and Larimichthys crocea (large yellow croaker) have lost binding to ghrelin. Do fish GHSRs use another peptide as their agonist? In the present study we tested to two fish motilins from D. rerio and L. chalumnae because motilin is distantly related to ghrelin. In ligand binding and activation assays, the fish GHSRs from D. rerio and L. crocea displayed no detectable or very low binding to all tested motilins; however, the fish GHSR from L. chalumnae bound to its motilin with high affinity and was efficiently activated by it. Therefore, it seemed that motilin is not a ligand for GHSR in the ray-finned fish D. rerio and L. crocea, but is an efficient agonist for GHSR in the lobe-finned fish L. chalumnae, one of the closest fish relatives of tetrapods. The results of present study suggested that GHSR might have two efficient agonists, ghrelin and motilin, in ancient fishes; however, this feature might be only preserved in some extant fishes with ancient evolutionary origins.

6.
Hepatology ; 75(5): 1218-1234, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34591986

RESUMO

BACKGROUND AND AIMS: NAFLD is considered as the hepatic manifestation of the metabolic syndrome, which includes insulin resistance, obesity and hyperlipidemia. NASH is a progressive stage of NAFLD with severe hepatic steatosis, hepatocyte death, inflammation, and fibrosis. Currently, no pharmacological interventions specifically tailored for NASH are approved. Ovarian tumor domain, ubiquitin aldehyde binding 1 (OTUB1), the founding member of deubiquitinases, regulates many metabolism-associated signaling pathways. However, the role of OTUB1 in NASH is unclarified. METHODS AND RESULTS: We demonstrated that mice with Otub1 deficiency exhibited aggravated high-fat diet-induced and high-fat high-cholesterol (HFHC) diet-induced hyperinsulinemia and liver steatosis. Notably, hepatocyte-specific overexpression of Otub1 markedly alleviated HFHC diet-induced hepatic steatosis, inflammatory responses, and liver fibrosis. Mechanistically, we identified apoptosis signal-regulating kinase 1 (ASK1) as a key candidate target of OTUB1 through RNA-sequencing analysis and immunoblot analysis. Through immunoprecipitation-mass spectrometry analysis, we further found that OTUB1 directly bound to tumor necrosis factor receptor-associated factor 6 (TRAF6) and suppressed its lysine 63-linked polyubiquitination, thus inhibiting the activation of ASK1 and its downstream pathway. CONCLUSIONS: OTUB1 is a key suppressor of NASH that inhibits polyubiquitinations of TRAF6 and attenuated TRAF6-mediated ASK1 activation. Targeting the OTUB1-TRAF6-ASK1 axis may be a promising therapeutic strategy for NASH.


Assuntos
Cisteína Endopeptidases/metabolismo , Hepatopatia Gordurosa não Alcoólica , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Transdução de Sinais , Fator 6 Associado a Receptor de TNF
7.
Amino Acids ; 55(11): 1557-1562, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37689599

RESUMO

Our recent study confirmed that the mature neuropeptide FAM237A, also known as neurosecretory protein GL (NPGL), is an efficient agonist for GPR83. The paralog FAM237B was previously reported as a weak agonist for GPR83. In the present study, we prepared mature human FAM237B via an intein-fusion approach and demonstrated that it could cause a significant activation effect at the nanomolar range (1‒10 nM) in a NanoBiT-based ß-arrestin recruitment assay. Thus, FAM237B appears to be another endogenous agonist for GPR83 and future in vivo studies will be required to confirm this.


Assuntos
Neuropeptídeos , Receptores Acoplados a Proteínas G , Humanos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo
8.
Microb Ecol ; 87(1): 24, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38159125

RESUMO

Drastic changes in hydrological conditions within floodplain ecosystems create distinct microbial habitats. However, there remains a lack of exploration regarding the variations in microbial function potentials across the flooding and drought seasons. In this study, metagenomics and environmental analyses were employed in floodplains that experience hydrological variations across four seasons. Analysis of functional gene composition, encompassing nitrogen, carbon, and sulfur metabolisms, revealed apparent differences between the flooding and drought seasons. The primary environmental drivers identified were water level, overlying water depth, submergence time, and temperature. Specific modules, e.g., the hydrolysis of ß-1,4-glucosidic bond, denitrification, and dissimilatory/assimilatory nitrate reduction to ammonium, exhibited higher relative abundance in summer compared to winter. It is suggested that cellulose degradation was potentially coupled with nitrate reduction during the flooding season. Phylogenomic analysis of metagenome-assembled genomes (MAGs) unveiled that the Desulfobacterota lineage possessed abundant nitrogen metabolism genes supported by pathway reconstruction. Variation of relative abundance implied its environmental adaptability to both the wet and dry seasons. Furthermore, a novel order was found within Methylomirabilota, containing nitrogen reduction genes in the MAG. Overall, this study highlights the crucial role of hydrological factors in modulating microbial functional diversity and generating genomes with abundant nitrogen metabolism potentials.


Assuntos
Microbiota , Água , Nitratos , Microbiota/genética , Metagenoma , Nitrogênio/metabolismo
9.
Sensors (Basel) ; 23(10)2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37430621

RESUMO

In this article, a high-gain millimeter-wave transmitarray antenna (TAA) maintaining scanning ability is developed, integrating an array feed as the primary emitter. The work is achieved within a limited aperture area, avoiding the replacement or extension of the array. The addition of a set of defocused phases along the scanning direction to the phase distribution of the monofocal lens allows the converging energy to be dispersed into the scanning scope. The beam forming algorithm proposed in this article can determine the excitation coefficients of the array feed source, and is beneficial to improve the scanning capability in array-fed transmitarray antennas. A transmitarray based on the square waveguide element illuminated by an array feed is designed with a focal-to-diameter ratio (F/D) of 0.6. A 1-D scan with a scope of -5° to 5° is realized through calculation. The measured results show that the transmitarray can achieve a high gain, 37.95 dBi at 160 GHz, although a maximum 2.2 dB error appears compared with the calculation in the operating band of 150-170 GHz. The proposed transmitarray has been proven to generate scannable high-gain beams in the millimeter-wave band and is expected to demonstrate its potential in other applications.

10.
Wetlands (Wilmington) ; 43(1): 10, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36683844

RESUMO

The increasing demand for water resources has triggered a series of water level regulation (WLR) projects, which exerts considerable effects on local hydrologic conditions. In particular, artificial impoundments, which may occur during the dry season in wetlands, increase the periods of waterlogging. However, little is known about their potential effects on biogeochemical cycling. To evaluate how impoundments affect nitrogen (N) cycling in the floodplain ecosystem, we conducted a mesocosm experiment to investigate N dynamics and the potential N-gene changes in the root-zone soil of the dominant plant in one large floodplain lake (Poyang Lake, China). The results indicated that, compared with the control, the 12 cm submergence treatment (SP12) caused NH4 +-N accumulation in the root-zone soil on day 14 and day 41. On the contrary, NO3 --N levels in SP12 were statistically lower than those in the control from day 7 to day 28. The curve of organic N had a tendency of declining as a whole. Changes in N-gene abundances revealed that SP12 significantly inhibited nitrification and enhanced denitrification in root-zone soil. Moreover, SP12 enhanced the links and complexity of the N-gene network, reflecting the increased correlations among the N transformations under flooding stress. Considering the increasing demand for WLR worldwide, the study about the effects of anti-seasonal submergence on biogeochemical cycling in floodplains provides insight into the ecological impacts of anthropogenic activities. Supplementary Information: The online version contains supplementary material available at 10.1007/s13157-022-01656-1.

11.
J Transl Med ; 20(1): 456, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36199069

RESUMO

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is a critical event contributing to more aggressive phenotypes in cancer cells. EMT is frequently activated in radiation-targeted cells during the course of radiotherapy, which often endows cancers with acquired radioresistance. However, the upstream molecules driving the signaling pathways of radiation-induced EMT have not been fully delineated. METHODS: In this study, RNA-seq-based transcriptome analysis was performed to identify the early responsive genes of HeLa cells to γ-ray irradiation. EMT-associated genes were knocked down by siRNA technology or overexpressed in HeLa cells and A549 cells, and the resulting changes in phenotypes of EMT and radiosensitivity were assessed using qPCR and Western blotting analyses, migration assays, colony-forming ability and apoptosis of flow cytometer assays. RESULTS: Through RNA-seq-based transcriptome analysis, we found that LPAR5 is downregulated in the early response of HeLa cells to γ-ray irradiation. Radiation-induced alterations in LPAR5 expression were further revealed to be a bidirectional dynamic process in HeLa and A549 cells, i.e., the early downregulating phase at 2 ~ 4 h and the late upregulating phase at 24 h post-irradiation. Overexpression of LPAR5 prompts EMT programing and migration of cancer cells. Moreover, increased expression of LPAR5 is significantly associated with IR-induced EMT and confers radioresistance to cancer cells. Knockdown of LPAR5 suppressed IR-induced EMT by attenuating the activation of ERK signaling and downstream Snail, MMP1, and MMP9 expression. CONCLUSIONS: LPAR5 is an important upstream regulator of IR-induced EMT that modulates the ERK/Snail pathway. This study provides further insights into understanding the mechanism of radiation-induced EMT and identifies promising targets for improving the effectiveness of cancer radiation therapy.


Assuntos
Metaloproteinase 1 da Matriz , Neoplasias , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/genética , Células HeLa , Humanos , Metaloproteinase 9 da Matriz , RNA Interferente Pequeno , Receptores de Ácidos Lisofosfatídicos
12.
Biomed Eng Online ; 21(1): 26, 2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35436915

RESUMO

BACKGROUND: Glioblastoma (GBM) is the most malignant grade of glioma. Highly aggressive characteristics of GBM and poor prognosis cause GBM-related deaths. The potential prognostic biomarkers remain to be demonstrated. This research builds up predictive gene targets of expression alterations in GBM utilizing bioinformatics analysis. METHODS AND RESULTS: The microarray datasets (GSE15824 and GSE16011) associated with GBM were obtained from Gene Expression Omnibus (GEO) database to identify the differentially expressed genes (DEGs) between GBM and non-tumor tissues. In total, 719 DEGs were obtained and subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) for function enrichment analysis. Furthermore, we constructed protein-protein Interaction (PPI) network among DEGs utilizing Search Tool for the Retrieval of Interacting Genes (STRING) online tool and Cytoscape software. The DEGs of degree > 10 was selected as hub genes, including 73 upregulated genes and 21 downregulated genes. Moreover, MCODE application in Cytoscape software was employed to identify three key modules involved in GBM development and prognosis. Additionally, we used the Gene expression profiling and interactive analyses (GEPIA) online tool to further confirm four genes involving in poor prognosis of GBM patients, including interferon-gamma-inducible protein 30 (IFI30), major histocompatibility complex class II-DM alpha (HLA-DMA), Prolyl 4-hydroxylase beta polypeptide (P4HB) and reticulocalbin-1 (RCN1). Furthermore, the correlation analysis indicated that the expression of IFI30, an acknowledged biomarker in glioma, was positively correlated with HLA-DMA, P4HB and RCN1. RCN1 expression was positively correlated with P4HB and HLA-DMA. Moreover, qRT-PCR and immunohistochemistry analysis further validated the upregulation of four prognostic markers in GBM tissues. CONCLUSIONS: Analysis of multiple datasets combined with global network information and experimental verification presents a successful approach to uncover the risk hub genes and prognostic markers of GBM. Our study identified four risk- and prognostic-related gene signatures, including IFI30, HLA-DMA, P4HB and RCN1. This gene sets contribute a new perspective to improve the diagnostic, prognostic, and therapeutic outcomes of GBM.


Assuntos
Glioblastoma , Glioma , Biomarcadores Tumorais/genética , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Glioblastoma/genética , Glioblastoma/metabolismo , Glioma/genética , Humanos , Prognóstico
13.
Chemistry ; 27(35): 9124-9128, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-33788984

RESUMO

Alloying platinum (Pt) with transition metals (M), as an established class of electrocatalysts, reduces the use of Pt and improves the electrocatalytic performance. However, the stability of transition metals in nanostructured platinum alloys is a fundamental and practical problem in electrocatalysis, due to leaching of transition metals under acidic operating condition. Here, a corrosion method has been developed for a Pt-Cu electrocatalyst with high activity (6.6 times that of commercial Pt/C) and excellent stability for the methanol oxidation reaction (MOR) under acidic operating conditions. The mechanism of formation has been studied, and possible mesostructured re-formation and atomic re-organization have been proposed. This work offers an effective strategy for the facile synthesis of a highly acid-stable PtM alloying and opens a door to high-performance design for electrocatalysts.

14.
Arch Biochem Biophys ; 704: 108872, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33857472

RESUMO

The gastric peptide ghrelin has important functions in energy metabolism and cellular homeostasis by activating growth hormone secretagogue receptor type 1a (GHSR1a). The N-terminal residues of ghrelin orthologs from all vertebrates are quite conserved; however, in orthologs from Cavia porcellus and Phyllostomus discolor, Ser2 and Leu5 are replaced by a smaller Ala and a positively charged Arg, respectively. In the present study, we first demonstrated that the hydrophobic Leu5 is essential for the function of human ghrelin, because Ala replacement caused an approximately 100-fold decrease in activity. However, replacement of Leu5 by an Arg residue caused much less disruption; further replacement of Ser2 by Ala almost restored full activity, although the [S2A] mutation itself showed slight detriments, implying that the positively charged Arg5 in the [S2A,L5R] mutant might form alternative interactions with certain receptor residues to compensate for the loss of the essential Leu5. To identify the responsible receptor residues, we screened GHSR1a mutants in which all conserved negatively charged residues in the extracellular regions and all aromatic residues in the ligand-binding pocket were mutated separately. According to the decrease in selectivity of the mutant receptors towards [S2A,L5R]ghrelin, we deduced that the positively charged Arg5 of the ghrelin mutant primarily interacts with the essential aromatic Phe286 at the extracellular end of the sixth transmembrane domain of GHSR1a by forming cation-π and π-π interactions. The present study provided new insights into the binding mechanism of ghrelin with its receptor, and thus would facilitate the design of novel ligands for GHSR1a.


Assuntos
Grelina/química , Receptores de Grelina/química , Animais , Quirópteros , Grelina/genética , Grelina/metabolismo , Cobaias , Células HEK293 , Humanos , Ligação Proteica , Domínios Proteicos , Receptores de Grelina/genética , Receptores de Grelina/metabolismo
15.
Amino Acids ; 53(6): 939-949, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33966114

RESUMO

Recent studies have demonstrated that liver-expressed antimicrobial peptide 2 (LEAP2) antagonizes the ghrelin receptor GHSR1a in mammals. However, its antagonistic function in lower vertebrates has not yet been tested. LEAP2 orthologs have been identified from a variety of fish species; however, previous studies all focused on their antimicrobial activity. To test whether LEAP2 functions as a GHSR1a antagonist in the lowest vertebrates, we studied the antagonism of a fish LEAP2 from Latimeria chalumnae, an extant coelacanth that is one of the closest living fish relatives of tetrapods. Using binding assays, we demonstrated that the coelacanth LEAP2 and ghrelin bound to the coelacanth GHSR1a with IC50 values in the nanomolar range. Using activation assays, we demonstrated that the coelacanth ghrelin activated the coelacanth GHSR1a with an EC50 value in the nanomolar range, and this activation effect was efficiently antagonized by a nanomolar range of the coelacanth LEAP2. In addition, we also showed that the human LEAP2 and ghrelin were as effective as their coelacanth orthologs towards the coelacanth GHSR1a; however, the coelacanth peptides had moderately lower activity towards the human GHSR1a. Thus, LEAP2 serves as an endogenous antagonist of the ghrelin receptor GHSR1a in coelacanth and the ghrelin-LEAP2-GHSR1a system has evolved slowly since its emergence in ancient fish.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Proteínas Sanguíneas , Evolução Molecular , Proteínas de Peixes , Peixes , Receptores de Grelina , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Proteínas Sanguíneas/genética , Proteínas Sanguíneas/metabolismo , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Peixes/genética , Peixes/metabolismo , Células HEK293 , Humanos , Receptores de Grelina/antagonistas & inibidores , Receptores de Grelina/genética , Receptores de Grelina/metabolismo
16.
Biochem J ; 477(17): 3199-3217, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32803260

RESUMO

Liver-expressed antimicrobial peptide 2 (LEAP2) was recently identified as a competitive antagonist for the G protein-coupled receptor GHSR1a, the cognate receptor for the gastric peptide ghrelin. LEAP2 plays important functions in energy metabolism by tuning the ghrelin-GHSR1a system. However, the molecular mechanism by which LEAP2 binds to GHSR1a is largely unknown. In the present study, we first conducted alanine-scanning mutagenesis on the N-terminal fragment of human LEAP2 and demonstrated that the positively charged Arg6 and the aromatic Phe4 are essential for LEAP2 binding to GHSR1a. To identify the receptor residues interacting with the essential Arg6 and Phe4 of LEAP2, we conducted extensive site-directed mutagenesis on GHSR1a. After all conserved negatively charged residues in the extracellular regions of human GHSR1a were mutated, only mutation of Asp99 caused much more detriments to GHSR1a binding to LEAP2 than binding to ghrelin, suggesting that the absolutely conserved Asp99 of GHSR1a probably interacts with the essential Arg6 of LEAP2. After five conserved Phe residues in the predicted ligand-binding pocket of human GHSR1a were mutated, three of them were identified as important for GHSR1a binding to LEAP2. According to a structural model of GHSR1a, we deduced that the adjacent Phe279 and Phe312 might interact with the essential Phe4 of LEAP2, while Phe119 might interact with the aromatic Trp5 of LEAP2. The present study provided new insights into the interaction of LEAP2 with its receptor, and would facilitate the design of novel ligands for GHSR1a in future studies.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Proteínas Sanguíneas/química , Receptores de Grelina/química , Substituição de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Proteínas Sanguíneas/genética , Proteínas Sanguíneas/metabolismo , Células HEK293 , Humanos , Mutagênese Sítio-Dirigida , Mutação de Sentido Incorreto , Ligação Proteica , Domínios Proteicos , Receptores de Grelina/genética , Receptores de Grelina/metabolismo
17.
Acta Biochim Biophys Sin (Shanghai) ; 53(12): 1662-1669, 2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34718375

RESUMO

Lipid metabolism disorder caused by the upregulation of lipogenic genes is a typical feature of prostate cancer. The synthesis of fatty acids is enhanced to accelerate the development of prostate cancer and is considered as a potential therapeutic target. Epicatechin gallate, an active compound of green tea, has been reported to modulate lipid metabolism. In this research, the potential role of epicatechin gallate in prostate cancer cells was evaluated. The results indicated that epicatechin gallate downregulates the expression of acetyl-CoA carboxylase, ATP citrate lyase, and fatty acid synthase in prostate cancer cells and prostate xenograft tissues, suggesting that epicatechin gallate can inhibit de novo fatty acid synthesis. Moreover, epicatechin gallate significantly restrains the migration rather than the viability of prostate cancer cells. PI3K/AKT/mTOR signaling pathway, which exhibits regulatory effect on lipogenesis, is also inhibited under epicatechin gallate treatment, while pretreatment with AKT activator SC79 or mTOR activator MHY1485 blocks the inhibitory effect of epicatechin gallate on the expression of lipogenic genes and the migration of prostate cancer cells. In conclusion, this study revealed that epicatechin gallate impairs the synthesis of fatty acids via inhibition PI3K/AKT/mTOR signaling pathway and then attenuates the migration of prostate cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Catequina/análogos & derivados , Movimento Celular/efeitos dos fármacos , Ácidos Graxos/biossíntese , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , ATP Citrato (pro-S)-Liase/genética , ATP Citrato (pro-S)-Liase/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Catequina/farmacologia , Catequina/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ácido Graxo Sintase Tipo I/genética , Ácido Graxo Sintase Tipo I/metabolismo , Ácidos Graxos/antagonistas & inibidores , Humanos , Lipogênese/efeitos dos fármacos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Sensors (Basel) ; 21(3)2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33573000

RESUMO

Proper stroke posture and rhythm are crucial for kayakers to achieve perfect performance and avoid the occurrence of sport injuries. The traditional video-based analysis method has numerous limitations (e.g., site and occlusion). In this study, we propose a systematic approach for evaluating the training performance of kayakers based on the multiple sensors fusion technology. Kayakers' motion information is collected by miniature inertial sensor nodes attached on the body. The extend Kalman filter (EKF) method is used for data fusion and updating human posture. After sensor calibration, the kayakers' actions are reconstructed by rigid-body model. The quantitative kinematic analysis is carried out based on joint angles. Machine learning algorithms are used for differentiating the stroke cycle into different phases, including entry, pull, exit and recovery. The experiment shows that our method can provide comprehensive motion evaluation information under real on-water scenario, and the phase identification of kayaker's motions is up to 98% validated by videography method. The proposed approach can provide quantitative information for coaches and athletes, which can be used to improve the training effects.


Assuntos
Postura , Dispositivos Eletrônicos Vestíveis , Algoritmos , Fenômenos Biomecânicos , Humanos , Movimento (Física) , Esportes
19.
Pharm Biol ; 59(1): 1286-1293, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34517734

RESUMO

CONTEXT: Rosmarinic acid (RA) dose-dependently ameliorates acetaminophen (APAP) induced hepatotoxicity in rats. However, whether RA hepatoprotective effect is by regulating RACK1 and its downstream signals is still unclear. OBJECTIVE: This study explores the RA protective effect on APAP-induced ALI and its mechanism. MATERIALS AND METHODS: Sixty Kunming mice 6-8 weeks old were randomly separated into six groups (n = 10) and pre-treated with normal saline, ammonium glycyrrhetate (AG) or RA (10, 20 or 40 mg/kg i.p./day) for two consecutive weeks. Then, APAP (300 mg/kg, i.g.) was administrated to induce ALI, except for the control. Serum alanine/aspartate aminotransferases (ALT and AST), malondialdehyde (MDA), superoxide dismutase (SOD) and histopathology were used to authenticate RA effect. The liver RACK1 and TNF-α were measured by western blot. RESULTS: Compared with the APAP group, different dosages RA significantly decreased ALT (52.09 ± 7.98, 55.13 ± 10.19, 65.08 ± 27.61 U/L, p < 0.05), AST (114.78 ± 19.87, 115.29 ± 31.91, 101.78 ± 21.85 U/L, p < 0.05), MDA (2.37 ± 0.87, 2.13 ± 0.87, 1.86 ± 0.39 nmol/mg, p < 0.01) and increased SOD (306.178 ± 90.80, 459.21 ± 58.54, 444.01 ± 78.09 U/mg, p < 0.05). With increasing doses of RA, RACK1 and TNF-α expression decreased. Moreover, the RACK1 and TNF-α levels were positively correlated with MDA (r = 0.8453 and r = 0.9391, p < 0.01). DISCUSSION AND CONCLUSIONS: Our findings support RA as a hepatoprotective agent to improve APAP-induced ALI and the antioxidant effect mediated through RACK1/TNF-α pathway.


Assuntos
Acetaminofen/toxicidade , Antioxidantes/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cinamatos/farmacologia , Depsídeos/farmacologia , Animais , Animais não Endogâmicos , Antioxidantes/administração & dosagem , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Cinamatos/administração & dosagem , Depsídeos/administração & dosagem , Relação Dose-Resposta a Droga , Ácido Glicirretínico/análogos & derivados , Ácido Glicirretínico/farmacologia , Masculino , Malondialdeído/metabolismo , Camundongos , Receptores de Quinase C Ativada/metabolismo , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Ácido Rosmarínico
20.
Angew Chem Int Ed Engl ; 60(40): 21846-21852, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34227191

RESUMO

Stimulated Raman scattering (SRS) microscopy in combination with innovative tagging strategies offers great potential as a universal high-throughput biomedical imaging tool. Here, we report rationally tailored small molecular monomers containing triple-bond units with large Raman scattering cross-sections, which can be polymerized at the nanoscale for enhancement of SRS contrast with smaller but brighter optical nanotags with artificial fingerprint output. From this, a class of triple-bond rich polymer nanoparticles (NPs) was engineered by regulating the relative dosages of three chemically different triple-bond monomers in co-polymerization. The bonding strategy allowed for 15 spectrally distinguishable triple-bond combinations. These accurately structured nano molecular aggregates, rather than long-chain macromolecules, could establish a universal method for generating small-sized biological SRS imaging tags with high sensitivity for high-throughput multi-color biomedical imaging.


Assuntos
Nanopartículas/química , Imagem Óptica , Polímeros/química , Humanos , Células MCF-7 , Estrutura Molecular , Análise Espectral Raman
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