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1.
Adv Sci (Weinh) ; : e2307819, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38569219

RESUMO

The gut-brain axis has recently emerged as a crucial link in the development and progression of Parkinson's disease (PD). Dysregulation of the gut microbiota has been implicated in the pathogenesis of this disease, sparking growing interest in the quest for non-invasive biomarkers derived from the gut for early PD diagnosis. Herein, an artificial intelligence-guided gut-microenvironment-triggered imaging sensor (Eu-MOF@Au-Aptmer) to achieve non-invasive, accurate screening for various stages of PD is presented. The sensor works by analyzing α-Syn in the gut using deep learning algorithms. By monitoring changes in α-Syn, the sensor can predict the onset of PD with high accuracy. This work has the potential to revolutionize the diagnosis and treatment of PD by allowing for early intervention and personalized treatment plans. Moreover, it exemplifies the promising prospects of integrating artificial intelligence (AI) and advanced sensors in the monitoring and prediction of a broad spectrum of diseases and health conditions.

2.
Islets ; 15(1): 2267725, 2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-37838950

RESUMO

The pancreatic ß cell synthesizes, packages, and secretes insulin in response to glucose-stimulation to maintain blood glucose homeostasis. Under diabetic conditions, a subset of ß cells fail and lose expression of key transcription factors (TFs) required for insulin secretion. Among these TFs is Pancreatic and duodenal homeobox 1 (PDX1), which recruits a unique subset of transcriptional coregulators to modulate its activity. Here we describe a novel interacting partner of PDX1, the Staphylococcal Nuclease and Tudor domain-containing protein (SND1), which has been shown to facilitate protein-protein interactions and transcriptional control through diverse mechanisms in a variety of tissues. PDX1:SND1 interactions were confirmed in rodent ß cell lines, mouse islets, and human islets. Utilizing CRISPR-Cas9 gene editing technology, we deleted Snd1 from the mouse ß cell lines, which revealed numerous differentially expressed genes linked to insulin secretion and cell proliferation, including limited expression of Glp1r. We observed Snd1 deficient ß cell lines had reduced cell expansion rates, GLP1R protein levels, and limited cAMP accumulation under stimulatory conditions, and further show that acute ablation of Snd1 impaired insulin secretion in rodent and human ß cell lines. Lastly, we discovered that PDX1:SND1 interactions were profoundly reduced in human ß cells from donors with type 2 diabetes (T2D). These observations suggest the PDX1:SND1 complex formation is critical for controlling a subset of genes important for ß cell function and is targeted in diabetes pathogenesis.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Animais , Humanos , Camundongos , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Endonucleases/genética , Endonucleases/metabolismo , Expressão Gênica , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Domínio Tudor
3.
Int J Surg ; 109(12): 4009-4017, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37678274

RESUMO

BACKGROUND: Cholangitis is common in patients with biliary atresia following Kasai portoenterostomy (KPE). The prompt use of empiric antibiotics is essential due to the lack of identified microorganisms. The authors aimed to validate a severity grading system to guide empiric antibiotic therapy in the management of post-KPE cholangitis. MATERIALS AND METHODS: This multicenter, prospective, randomized, open-label study recruited patients with post-KPE cholangitis and was conducted from January 2018 to December 2019. On admission, patients were categorized into mild, moderate, and severe cholangitis according to the severity grading system. Patients in the mild cholangitis group were randomized to receive cefoperazone sodium tazobactam sodium (CSTS) or meropenem (MEPM). Patients with severe cholangitis were randomized to treatment with MEPM or a combination of MEPM plus immunoglobulin (MEPM+IVIG). Patients with moderate cholangitis received MEPM. RESULTS: The primary endpoint was duration of fever (DOF). Secondary outcomes included blood culture, length of hospital stay, incidence of recurrent cholangitis, jaundice clearance rate, and native liver survival (NLS). For mild cholangitis, DOF, and length of hospital stay were similar between those treated with CSTS or MEPM (all P >0.05). In addition, no significant difference in recurrence rate, jaundice clearance rate, and NLS was observed between patients treated with CSTS and MEPM at 1-month, 3-month, and 6-month follow-up. In patients with moderate cholangitis, the DOF was 36.00 (interquartile range: 24.00-48.00) h. In severe cholangitis, compared with MEPM, MEPM+IVIG decreased DOF and improved liver function by reducing alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and direct bilirubin at 1-month follow-up. However, recurrence rate, jaundice clearance rate, and NLS did not differ significantly between MEPM+IVIG and MEPM at 1-month, 3-month, and 6-month follow-up. CONCLUSIONS: In patients with post-KPE cholangitis, MEPM is not superior to CSTS for the treatment of mild cholangitis. However, MEPM+IVIG treatment was associated with better short-term clinical outcomes in patients with severe cholangitis.


Assuntos
Atresia Biliar , Colangite , Icterícia , Criança , Humanos , Lactente , Portoenterostomia Hepática/efeitos adversos , Estudos Prospectivos , Imunoglobulinas Intravenosas , Atresia Biliar/cirurgia , Atresia Biliar/complicações , Colangite/tratamento farmacológico , Colangite/etiologia , Icterícia/complicações , Antibacterianos/uso terapêutico , Meropeném , Estudos Retrospectivos , Resultado do Tratamento
4.
Front Surg ; 10: 1055128, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36874458

RESUMO

Background: Hirschsprung-associated enterocolitis (HAEC) is a common and life-threatening complication of Hirschsprung's disease (HSCR), which can occur before and after surgery. The aim of this study was to identify the risk factors associated with the development of HAEC. Methods: We retrospectively reviewed the medical records of HSCR patients admitted to the Children's Hospital of Shanxi Province, China, between January 2011 and August 2021. Diagnosis of HAEC was made using a scoring system with cutoff values ≥4 and included the patient's history, physical examination, and radiological and laboratory findings. The results are shown as frequency (%). The chi-square test was used to analyze a single factor with a significance level of P < 0.05. Logistic regression analysis was used to analyze multiple factors. Results: A total of 324 patients were included in this study, with 266 males and 58 females. In total, 34.3% (111/324) of patients had HAEC, including 85 males and 26 females; 18.9% (61/324) of patients had preoperative HAEC; and 15.4% (50/324) of patients had postoperative HAEC within one year after surgery. Gender, age at definitive therapy, and feeding methods were not found to be associated with preoperative HAEC in univariate analysis. Respiratory infection was associated with preoperative HAEC (P = 0.00003). No association was found between gender and age at definitive therapy and postoperative HAEC. Postoperative HAEC was associated with microcytic hypochromic anemia (P = 0.00058), preoperative history of HAEC (P = 0.00120), the creation of a preoperative stoma (P = 0.00097), long segment or total colon HSCR (P = 0.00057), and hypoalbuminemia (P = 0.03225). Regression analysis showed that microcytic hypochromic anemia (OR=2.716, 95% CI = 1.418-5.203, P = 0.003), preoperative history of HAEC (OR=2.814, 95% CI = 1.429-5.542, P = 0.003), the creation of a preoperative stoma (OR=2.332, 95% CI = 1.003-5.420, P = 0.049), and long segment or total colon HSCR (OR=2.167, 95% CI = 1.054-4.456, P = 0.035) were associated with postoperative HAEC. Conclusion: This study revealed that the incidence of preoperative HAEC at our hospital was associated with respiratory infections. In addition, microcytic hypochromic anemia, preoperative history of HAEC, the creation of a preoperative stoma, and long segment or total colon HSCR were risk factors of postoperative HAEC. The most important finding of this study was that microcytic hypochromic anemia was a risk factor for postoperative HAEC, which has been rarely reported. Further studies with larger sample sizes are necessary to confirm these findings.

5.
Anal Bioanal Chem ; 414(29-30): 8331-8339, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36258085

RESUMO

The development of disease detection by biosensors represents one of the key components of medical science. However, millions of people are still misdiagnosed each year due to the poor efficacy and thermal instability of biosensors. Using horseradish peroxidase (HRP) as a paradigm, we offer a rational design strategy to optimize the thermostability and activity of biosensors by biomimetic mineralization. To overcome the weak thermostability of the biosensor, the mineralization of Fe-MOF forms an armor on HRP that protects against high temperature. Additionally, the biomimetic mineralization HRP@Fe-MOF can double-catalyze the TMB/H2O2 chromogenic system for color development. The biosensor can also be recycled through simple heat treatment due to the thermally stable aptamer and biomimetic mineralization HRP@Fe-MOF. The optical biosensor based on this sensitive spectral transformation was successfully developed for the measurement of AßO with an outstanding linear range (0.0001-10 nM) and a low limit of detection (LOD) of 0.03 pM. This promising platform will open up new avenues for the detection of AßO in the early diagnosis of Alzheimer's disease (AD).


Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Humanos , Peroxidase do Rábano Silvestre , Biomimética , Peróxido de Hidrogênio , Doença de Alzheimer/diagnóstico
6.
Cell Rep ; 38(1): 110179, 2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34986353

RESUMO

G protein-coupled receptors (GPCRs) in intestinal enteroendocrine cells (EECs) respond to nutritional, neural, and microbial cues and modulate the release of gut hormones. Here we show that Gpr17, an orphan GPCR, is co-expressed in glucagon-like peptide-1 (GLP-1)-expressing EECs in human and rodent intestinal epithelium. Acute genetic ablation of Gpr17 in intestinal epithelium improves glucose tolerance and glucose-stimulated insulin secretion (GSIS). Importantly, inducible knockout (iKO) mice and Gpr17 null intestinal organoids respond to glucose or lipid ingestion with increased secretion of GLP-1, but not the other incretin glucose-dependent insulinotropic polypeptide (GIP). In an in vitro EEC model, overexpression or agonism of Gpr17 reduces voltage-gated calcium currents and decreases cyclic AMP (cAMP) production, and these are two critical factors regulating GLP-1 secretion. Together, our work shows that intestinal Gpr17 signaling functions as an inhibitory pathway for GLP-1 secretion in EECs, suggesting intestinal GPR17 is a potential target for diabetes and obesity intervention.


Assuntos
Células Enteroendócrinas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Glucose/metabolismo , Mucosa Intestinal/metabolismo , Proteínas do Tecido Nervoso/genética , Receptores Acoplados a Proteínas G/genética , Animais , Glicemia/análise , Cálcio/metabolismo , Linhagem Celular , AMP Cíclico/metabolismo , Diabetes Mellitus/patologia , Feminino , Polipeptídeo Inibidor Gástrico/metabolismo , Teste de Tolerância a Glucose , Células HEK293 , Células HeLa , Humanos , Incretinas/metabolismo , Insulina/metabolismo , Secreção de Insulina/fisiologia , Mucosa Intestinal/citologia , Masculino , Camundongos , Camundongos Knockout , Obesidade/patologia , Receptores dos Hormônios Gastrointestinais/metabolismo
7.
J Biol Chem ; 298(1): 101431, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34801552

RESUMO

Insulin resistance impairs postprandial glucose uptake through glucose transporter type 4 (GLUT4) and is the primary defect preceding type 2 diabetes. We previously generated an insulin-resistant mouse model with human GLUT4 promoter-driven insulin receptor knockout (GIRKO) in the muscle, adipose, and neuronal subpopulations. However, the rate of diabetes in GIRKO mice remained low prior to 6 months of age on normal chow diet (NCD), suggesting that additional factors/mechanisms are responsible for adverse metabolic effects driving the ultimate progression of overt diabetes. In this study, we characterized the metabolic phenotypes of the adult GIRKO mice acutely switched to high-fat diet (HFD) feeding in order to identify additional metabolic challenges required for disease progression. Distinct from other diet-induced obesity (DIO) and genetic models (e.g., db/db mice), GIRKO mice remained leaner on HFD feeding, but developed other cardinal features of insulin resistance syndrome. GIRKO mice rapidly developed hyperglycemia despite compensatory increases in ß-cell mass and hyperinsulinemia. Furthermore, GIRKO mice also had impaired oral glucose tolerance and a limited glucose-lowering benefit from exendin-4, suggesting that the blunted incretin effect contributed to hyperglycemia. Secondly, GIRKO mice manifested severe dyslipidemia while on HFD due to elevated hepatic lipid secretion, serum triglyceride concentration, and lipid droplet accumulation in hepatocytes. Thirdly, GIRKO mice on HFD had increased inflammatory cues in the gut, which were associated with the HFD-induced microbiome alterations and increased serum lipopolysaccharide (LPS). In conclusion, our studies identified important gene/diet interactions contributing to diabetes progression, which might be leveraged to develop more efficacious therapies.


Assuntos
Diabetes Mellitus Tipo 2 , Dieta Hiperlipídica , Intolerância à Glucose , Transportador de Glucose Tipo 4 , Hiperglicemia , Resistência à Insulina , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Transportador de Glucose Tipo 4/biossíntese , Transportador de Glucose Tipo 4/metabolismo , Hiperglicemia/sangue , Hiperglicemia/etiologia , Hiperglicemia/metabolismo , Insulina/metabolismo , Resistência à Insulina/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
8.
J Biol Chem ; 297(1): 100881, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34144038

RESUMO

GPR17 is a G-protein-coupled receptor (GPCR) implicated in the regulation of glucose metabolism and energy homeostasis. Such evidence is primarily drawn from mouse knockout studies and suggests GPR17 as a potential novel therapeutic target for the treatment of metabolic diseases. However, links between human GPR17 genetic variants, downstream cellular signaling, and metabolic diseases have yet to be reported. Here, we analyzed GPR17 coding sequences from control and disease cohorts consisting of individuals with adverse clinical metabolic deficits including severe insulin resistance, hypercholesterolemia, and obesity. We identified 18 nonsynonymous GPR17 variants, including eight variants that were exclusive to the disease cohort. We characterized the protein expression levels, membrane localization, and downstream signaling profiles of nine GPR17 variants (F43L, V96M, V103M, D105N, A131T, G136S, R248Q, R301H, and G354V). These nine GPR17 variants had similar protein expression and subcellular localization as wild-type GPR17; however, they showed diverse downstream signaling profiles. GPR17-G136S lost the capacity for agonist-mediated cAMP, Ca2+, and ß-arrestin signaling. GPR17-V96M retained cAMP inhibition similar to GPR17-WT, but showed impaired Ca2+ and ß-arrestin signaling. GPR17-D105N displayed impaired cAMP and Ca2+ signaling, but unaffected agonist-stimulated ß-arrestin recruitment. The identification and functional profiling of naturally occurring human GPR17 variants from individuals with metabolic diseases revealed receptor variants with diverse signaling profiles, including differential signaling perturbations that resulted in GPCR signaling bias. Our findings provide a framework for structure-function relationship studies of GPR17 signaling and metabolic disease.


Assuntos
Síndrome Metabólica/genética , Mutação de Sentido Incorreto , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais , Cálcio/metabolismo , AMP Cíclico/metabolismo , Células HEK293 , Humanos , Transporte Proteico , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , beta-Arrestinas/metabolismo
9.
Nutrients ; 12(10)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003412

RESUMO

High-fat diet (HFD) has been shown to accelerate Alzheimer's disease (AD) pathology, but the exact molecular and cellular mechanisms remain incompletely understood. Moreover, it is unknown whether AD mice are more susceptible to HFD-induced metabolic dysfunctions. To address these questions, we used 5xFAD mice as an Alzheimer's disease model to study the physiological and molecular underpinning between HFD-induced metabolic defects and AD pathology. We systematically profiled the metabolic parameters, the gut microbiome composition, and hippocampal gene expression in 5xFAD and wild type (WT) mice fed normal chow diet and HFD. HFD feeding impaired energy metabolism in male 5xFAD mice, leading to increased locomotor activity, energy expenditure, and food intake. 5xFAD mice on HFD had elevated circulating lipids and worsened glucose intolerance. HFD caused profound changes in gut microbiome compositions, though no difference between genotype was detected. We measured hippocampal mRNAs related to AD neuropathology and neuroinflammation and showed that HFD elevated the expression of apoptotic, microglial, and amyloidogenic genes in 5xFAD mice. Pathway analysis revealed that differentially regulated genes were involved in insulin signaling, cytokine signaling, cellular stress, and neurotransmission. Collectively, our results showed that 5xFAD mice were more susceptible to HFD-induced metabolic dysregulation and suggest that targeting metabolic dysfunctions can ameliorate AD symptoms via effects on insulin signaling and neuroinflammation in the hippocampus.


Assuntos
Doença de Alzheimer/metabolismo , Proteínas Amiloidogênicas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Inflamação Neurogênica/metabolismo , Transdução de Sinais/fisiologia , Doença de Alzheimer/etiologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Ingestão de Alimentos/fisiologia , Metabolismo Energético/fisiologia , Microbioma Gastrointestinal/genética , Expressão Gênica , Genótipo , Intolerância à Glucose/sangue , Intolerância à Glucose/etiologia , Hipocampo/metabolismo , Inflamação , Insulina/metabolismo , Lipídeos/sangue , Locomoção/fisiologia , Masculino , Camundongos , Microglia/metabolismo , Inflamação Neurogênica/etiologia , RNA Mensageiro/metabolismo , Fatores de Risco , Transmissão Sináptica/genética
10.
Mikrochim Acta ; 187(9): 515, 2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32839875

RESUMO

To early effectively detect amyloid-beta (Aß) oligomers, a label-free reusable aptasensor was designed. This aptasensor based on a luminescent nanoscale lanthanum-based metal-organic framework (L-MOF)-armored single-stranded DNA antibody (MOF-armored-anti-DNA antibody) as signal tags and aptamer bound to magnetic beads (Apt-MB) as capture probe. The reusable aptasensor combines signal tag and capture probe with antigen-antibody interaction. When the reusable aptasensor is formed, the strong fluorescence intensity of L-MOF will "turn off" by photo-induced electron transfer from excited states to an unfilled d shell of iron cations on the nanoparticle surface. Upon the presence of Aß oligomers in serum samples, they can be especially distinguished with the Aß oligomers aptamer in capture probes and then signal tags are released into the solution for developing the fluorescence aptasensor under excitation/emission 365 nm/430 nm. Meanwhile, the aptamer was recovered from the complex of Aß oligomers/Apt-MB by heat treatment. When the temperature returns to room temperature, the recovered aptamer in the capture probe can once again bound to the MOF-armored-anti-DNA antibody for reuse. The label-free reusable aptasensor system detection has high sensitivity and selectivity toward Aß oligomers (LOD = 0.4 pg/mL) and an excellent linear range (0.001-100 ng/mL). This strategy is a fruitful step for the development of reusable aptasensor and may turn on new avenues for the applications of Aß oligomer detection in clinical diagnosis.Graphical abstract.


Assuntos
Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Peptídeos beta-Amiloides/química , Anticorpos Imobilizados/imunologia , Aptâmeros de Nucleotídeos/imunologia , DNA de Cadeia Simples/química , DNA de Cadeia Simples/imunologia , Corantes Fluorescentes/química , Humanos , Separação Imunomagnética , Lantânio/química , Limite de Detecção , Nanopartículas de Magnetita/química , Estruturas Metalorgânicas/química , Estrutura Quaternária de Proteína , Espectrometria de Fluorescência
11.
J Org Chem ; 85(14): 9290-9300, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32583669

RESUMO

A new enantioselective Michael addition between 3-(3-hydroxy-1H-pyrazol-1-yl)oxindole, a new synthon generated from isatin N,N'-cyclic azomethine imine 1,3-dipole, and ß-nitrostyrene has been disclosed. A series of chiral 3-(3-oxo-2,3-dihydro-1H-pyrazol-1-yl) disubstituted oxindoles were obtained in excellent results (up to 97% yield, up to 94% ee) with moderate to good diastereoselectivities (up to 4.3:1 dr).

12.
Pediatr Surg Int ; 36(6): 711-718, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32367198

RESUMO

AIM: We evaluated the demographic of biliary atresia (BA) children from twins family and aimed to investigated what it can add to the twins' literature and our understanding of the disease. METHODS: This study contains 11 medical centers in mainland China and the medical record of twins with BA was retrospectively analyzed from January 2012 to December 2018. Follow-up was carried out by out-patient review and questionnaire. RESULTS: The study included 19 twin pairs in whom there was discordance for BA. Sixteen (84.2%) affected twin underwent Kasai Procedure (KP); median age at KP was 78 (49-168) days. There were ten affected twins that became jaundice-free at 3 months post-KP, and eight occurred with different degrees of cholangitis post-KP. Six affected twins received Liver Transplantation (LT) successfully. The 2 year native liver survival rate and the 2 year overall survival rate of affected twins were 61.1 and 94.4%, respectively. There were three affected monozygotic (MZ) twins and one healthy co-twin with BA-associated congenital malformations, all of which were cardiac malformations. The number of virus infection of affected MZ twins was significantly more (p = 0.04) than affected dizygotic (DZ) twin. CONCLUSIONS: Discordance for BA in 19 pairs of twins supported that BA may be related to genetic phenotype or penetrance. The difference in genetic background between MZ and DZ affects the susceptibility of the host to virus infection. High acceptance of KP (84.2%) in our study implied a high motivation for treatment for twins with BA. Delays of KP (78 days) in affected twin may be related to the postnatal gradual onset and the late diagnosis.


Assuntos
Atresia Biliar/cirurgia , Portoenterostomia Hepática/métodos , Gêmeos Monozigóticos , Atresia Biliar/epidemiologia , China/epidemiologia , Doenças em Gêmeos , Feminino , Humanos , Recém-Nascido , Transplante de Fígado , Masculino , Morbidade/tendências , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida/tendências
13.
J Org Chem ; 85(5): 3921-3928, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-31944112

RESUMO

An abnormal [3 + 2]-cycloaddition and highly effective and convenient one-step preparation of tetracyclic bispirooxindoles containing two all-carbon quaternary spirocenters from isatin N,N'-cyclic azomethine imine 1,3-dipole and 3-methyleneoxindole in the presence of catalytic organic base has been disclosed. A variety of bispirooxindoles bearing a dinitrogen heterocycle with four adjacent cycles have been obtained in excellent yields (up to 95%) and diastereoselectivities (>99:1) under mild conditions.

14.
Mikrochim Acta ; 187(2): 114, 2020 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919722

RESUMO

Amyloid-beta (Aß) oligomers causing neuron damage are regarded as potential therapeutic targets and diagnostic markers for Alzheimer's disease (AD). A homogeneous turn-on fluorometric aptasensor is described for Aß oligomers. It is highly selective and non-invasive and based on (a) the use of a luminescent metal-organic framework carrying aptamer-modified AuNPs (L-MOF/Apt-Au) as tracking agent, and (b) enzyme-assisted target recycling signal amplification. The tracking agent does not emit fluoresce by fluorescence resonance energy transfer (FRET) between the luminescent MOF as donor and Apt-Au as the acceptor under the excitation wavelength of 466 nm. When Aß oligomers are added to the tracking agent solution, the Apt-Au on tracking agent can preferentially bind with Aß oligomers and then be released. This turns the "off" signal of the luminescent MOF tracer to the "on" state. The enzyme (Rec Jf exonuclease) added into the supernatant further improves sensitivity due to enzyme-assisted target-recycling signal amplification. The assay has an excellent linear response to Aß oligomers from 1.0 pM to 10 nM, with a detection limit of 0.3 pM. This homogeneous turn-on fluorometric method is expected to have potential and applications in clinical diagnosis. Graphical abstractSchematic representation of fluorometric assay for amyloid-ß oligomers based on luminescence metal-organic framework nanocomposites as tracking agent with exonuclease-assisted target recycling.


Assuntos
Peptídeos beta-Amiloides/análise , Aptâmeros de Nucleotídeos , Fluorometria/métodos , Estruturas Metalorgânicas/química , Reciclagem/métodos , Doença de Alzheimer/diagnóstico , Técnicas Biossensoriais/métodos , Exonucleases , Ouro , Humanos , Limite de Detecção , Nanopartículas Metálicas/química
16.
Nutr Diabetes ; 9(1): 29, 2019 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-31611548

RESUMO

BACKGROUND: Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARH) control energy homeostasis by sensing hormonal and nutrient cues and activating secondary melanocortin sensing neurons. We identified the expression of a G protein-coupled receptor, Gpr17, in the ARH and hypothesized that it contributes to the regulatory function of POMC neurons on metabolism. METHODS: In order to test this hypothesis, we generated POMC neuron-specific Gpr17 knockout (PGKO) mice and determined their energy and glucose metabolic phenotypes on normal chow diet (NCD) and high-fat diet (HFD). RESULTS: Adult PGKO mice on NCD displayed comparable body composition and metabolic features measured by indirect calorimetry. By contrast, PGKO mice on HFD demonstrated a sexually dimorphic phenotype with female PGKO mice displaying better metabolic homeostasis. Notably, female PGKO mice gained significantly less body weight and adiposity (p < 0.01), which was associated with increased energy expenditure, locomotor activity, and respiratory quotient, while males did not have an overt change in energy homeostasis. Though PGKO mice of both sexes had comparable glucose and insulin tolerance, detailed analyses of liver gene expression and serum metabolites indicate that PGKO mice could have reduced gluconeogenesis and increased lipid utilization on HFD. To elucidate the central-based mechanism(s) underlying the better-preserved energy and glucose homeostasis in PGKO mice on HFD, we examined the electrophysiological properties of POMC neurons and found Gpr17 deficiency led to increased spontaneous action potentials. Moreover, PGKO mice, especially female knockouts, had increased POMC-derived alpha-melanocyte stimulating hormone and beta-endorphin despite a comparable level of prohormone POMC in their hypothalamic extracts. CONCLUSIONS: Gpr17 deficiency in POMC neurons protects metabolic homeostasis in a sex-dependent manner during dietary and aging challenges, suggesting that Gpr17 could be an effective anti-obesity target in specific populations with poor metabolic control.


Assuntos
Peso Corporal/fisiologia , Encéfalo/metabolismo , Resistência à Insulina/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Pró-Opiomelanocortina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Envelhecimento/metabolismo , Animais , Dieta Hiperlipídica , Metabolismo Energético/fisiologia , Feminino , Homeostase/fisiologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos Knockout , Atividade Motora/fisiologia , Proteínas do Tecido Nervoso/genética , Receptores Acoplados a Proteínas G/genética , Fatores Sexuais
17.
Angew Chem Int Ed Engl ; 58(47): 16800-16805, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31486209

RESUMO

Surface recombination at the photoanode/electrolyte junction seriously impedes photoelectrochemical (PEC) performance. Through coating of photoanodes with oxygen evolution catalysts, the photocurrent can be enhanced; however, current systems for water splitting still suffer from high recombination. We describe herein a novel charge transfer system designed with BiVO4 as a prototype. In this system, porphyrins act as an interfacial-charge-transfer mediator, like a volleyball setter, to efficiently suppress surface recombination through higher hole-transfer kinetics rather than as a traditional photosensitizer. Furthermore, we found that the introduction of a "setter" can ensure a long lifetime of charge carriers at the photoanode/electrolyte interface. This simple interface charge-modulation system exhibits increased photocurrent density from 0.68 to 4.75 mA cm-2 and provides a promising design strategy for efficient photogenerated charge separation to improve PEC performance.

18.
BMC Med Genomics ; 12(Suppl 6): 108, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31345219

RESUMO

BACKGROUND: Genetic loss-of-function variants (LoFs) associated with disease traits are increasingly recognized as critical evidence for the selection of therapeutic targets. We integrated the analysis of genetic and clinical data from 10,511 individuals in the Mount Sinai BioMe Biobank to identify genes with loss-of-function variants (LoFs) significantly associated with cardiovascular disease (CVD) traits, and used RNA-sequence data of seven metabolic and vascular tissues isolated from 600 CVD patients in the Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task (STARNET) study for validation. We also carried out in vitro functional studies of several candidate genes, and in vivo studies of one gene. RESULTS: We identified LoFs in 433 genes significantly associated with at least one of 10 major CVD traits. Next, we used RNA-sequence data from the STARNET study to validate 115 of the 433 LoF harboring-genes in that their expression levels were concordantly associated with corresponding CVD traits. Together with the documented hepatic lipid-lowering gene, APOC3, the expression levels of six additional liver LoF-genes were positively associated with levels of plasma lipids in STARNET. Candidate LoF-genes were subjected to gene silencing in HepG2 cells with marked overall effects on cellular LDLR, levels of triglycerides and on secreted APOB100 and PCSK9. In addition, we identified novel LoFs in DGAT2 associated with lower plasma cholesterol and glucose levels in BioMe that were also confirmed in STARNET, and showed a selective DGAT2-inhibitor in C57BL/6 mice not only significantly lowered fasting glucose levels but also affected body weight. CONCLUSION: In sum, by integrating genetic and electronic medical record data, and leveraging one of the world's largest human RNA-sequence datasets (STARNET), we identified known and novel CVD-trait related genes that may serve as targets for CVD therapeutics and as such merit further investigation.


Assuntos
Doenças Cardiovasculares/genética , Genômica , Mutação , Doenças Cardiovasculares/sangue , Colesterol/sangue , Genótipo , Humanos , Triglicerídeos/sangue
19.
Mikrochim Acta ; 186(8): 515, 2019 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-31280384

RESUMO

A visualization strategy is described for the detection of clenbuterol (CLB). It is using of antibody against dsDNA and G-quadruplex/hemin labeled on a metal organic framework of type MIL-101(Fe) (G-quadruplex/hemin-anti-DNA/MIL-101) acting as a peroxidase mimetic, and magnetic beads modified with aptamer and complementary DNA (MB/Apt-cDNA) as capture probes. The detection reagent was prepared via the reactions between the double stranded DNA (Apt-cDNA) in capture probes and anti-DNA in peroxidase mimetic. In the presence of CLB, the aptamer on the magnetic beads preferentially binds CLB, and the peroxidase mimetic is released to the supernatant after magnetic separation. The released peroxidase mimetic can catalyze the TMB/H2O2 chromogenic system under mild conditions. This leads to the development of a blue-green coloration whose absorbance is measured at 650 nm. The detection limit is as low as 34 fM of CLB. The method was applied to the determination of CLB in pork samples and gave results that were consistent with data obtained with an ELISA kit. Graphical abstract A visualization strategy is described for the detection of clenbuterol. The selectivity of detection system for clenbuterol is excellent compared with other interferents. The method was applied to the determination of CLB in pork samples.


Assuntos
Agonistas Adrenérgicos beta/análise , Clembuterol/análise , Contaminação de Alimentos/análise , Carne Vermelha/análise , Suínos , Agonistas Adrenérgicos beta/química , Animais , Anticorpos/química , Aptâmeros de Nucleotídeos/química , Biomimética , Clembuterol/química , Colorimetria , DNA/química , DNA/imunologia , Quadruplex G , Hemina/química , Ferro/química , Fenômenos Magnéticos , Estruturas Metalorgânicas/química , Peroxidase/química
20.
Endocrinology ; 160(9): 2038-2048, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31199472

RESUMO

Insulin signaling in the central nervous system influences satiety, counterregulation, and peripheral insulin sensitivity. Neurons expressing the Glut4 glucose transporter influence peripheral insulin sensitivity. Here, we analyzed the effects of insulin receptor (IR) signaling in hypothalamic Glut4 neurons on glucose sensing as well as leptin and amino acid signaling. By measuring electrophysiological responses to low glucose conditions, we found that the majority of Glut4 neurons in the ventromedial hypothalamus (VMH) were glucose excitatory neurons. GLUT4-Cre-driven insulin receptor knockout mice with a combined ablation of IR in Glut4-expressing tissues showed increased counterregulatory response to either 2-deoxyglucose-induced neuroglycopenia or systemic insulin-induced hypoglycemia. The latter response was recapitulated in mice with decreased VMH IR expression, suggesting that the effects on the counterregulatory response are likely mediated through the deletion of IRs on Glut4 neurons in the VMH. Using immunohistochemistry in fluorescently labeled hypothalamic Glut4 neurons, we showed that IR signaling promoted hypothalamic cellular signaling responses to the rise of insulin, leptin, and amino acids associated with feeding. We concluded that hypothalamic Glut4 neurons modulated the glucagon counterregulatory response and that IR signaling in Glut4 neurons was required to integrate hormonal and nutritional cues for the regulation of glucose metabolism.


Assuntos
Transportador de Glucose Tipo 4/fisiologia , Receptor de Insulina/fisiologia , Núcleo Hipotalâmico Ventromedial/fisiologia , Animais , Glucagon/sangue , Glucose/metabolismo , Hipoglicemia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL
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