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1.
Nat Commun ; 15(1): 5830, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992057

RESUMO

Impaired ion channels regulating Golgi pH lead to structural alterations in the Golgi apparatus, such as fragmentation, which is found, along with cognitive impairment, in Alzheimer's disease. However, the causal relationship between altered Golgi structure and cognitive impairment remains elusive due to the lack of understanding of ion channels in the Golgi apparatus of brain cells. Here, we identify that a transmembrane protein TMEM87A, renamed Golgi-pH-regulating cation channel (GolpHCat), expressed in astrocytes and neurons that contributes to hippocampus-dependent memory. We find that GolpHCat displays unique voltage-dependent currents, which is potently inhibited by gluconate. Additionally, we gain structural insights into the ion conduction through GolpHCat at the molecular level by determining three high-resolution cryogenic-electron microscopy structures of human GolpHCat. GolpHCat-knockout mice show fragmented Golgi morphology and altered protein glycosylation and functions in the hippocampus, leading to impaired spatial memory. These findings suggest a molecular target for Golgi-related diseases and cognitive impairment.


Assuntos
Complexo de Golgi , Hipocampo , Camundongos Knockout , Neurônios , Animais , Humanos , Masculino , Camundongos , Astrócitos/metabolismo , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/patologia , Microscopia Crioeletrônica , Glicosilação , Complexo de Golgi/metabolismo , Células HEK293 , Hipocampo/metabolismo , Concentração de Íons de Hidrogênio , Canais Iônicos/metabolismo , Canais Iônicos/genética , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Memória/fisiologia , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Memória Espacial/fisiologia
2.
J Am Chem Soc ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38847772

RESUMO

Despite the synthetic versatility of difluorocarbene, its high reactivity severely regulates widespread applications of difluorocarbene in organic synthesis. Here, we report a copper difluorocarbene-involved catalytic coupling, representing a new mode of the difluoromethylation reaction. This method allows difluoromethylation of a wide range of readily available allyl/propargyl electrophiles with NaBH3CN and low-cost difluorocarbene precursor BrCF2CO2K, featuring high cost-efficiency, high stereo- and regioselectivities, and high functional group tolerance, even with complex drug-like molecules. Applying the method led to the efficient synthesis of deuterated difluoromethylated compounds of medicinal interest. The resulting difluoromethylated allyl and allenyl products can serve as versatile synthons for diverse transformations, rendering the approach attractive for synthesizing complex fluorinated structures. Experimental mechanistic studies and computational calculations reveal that the formation of a difluoromethylcopper(I) intermediate through the nucleophilic attack of boron hydride on the copper(I) difluorocarbene is the key step in the reaction.

3.
J Am Chem Soc ; 146(15): 10984-10992, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38578866

RESUMO

Dinitrogen (N2) activation and functionalization through N-N bond cleavage and N-C bond formation are of great interest and importance but remain highly challenging. We report here for the first time N2 cleavage and selective multicoupling with isocyanides in a dititanium dihydride framework. The reaction of a dinitrogen dititanium dihydride complex [{(acriPNP)Ti}2(µ-η1:η2-N2)(µ-H)2] (1) with an excess (four or more equivalents) of p-methoxyphenyl isocyanide at room temperature gave a novel amidoamidinatoguanidinate complex [(acriPNP)Ti{NC(═NR)NC(═NR)CH2NR}Ti(acriPNP)(CNR)] (2, acriPNP = 4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9H-acridin-10-ide; R = p-MeOC6H4) through N2 splitting and coupling with three isocyanide molecules. When 1 equiv of p-methoxyphenyl isocyanide was used to react with 1 at -30 °C, the hydrogenation of the isocyanide unit by the two hydride ligands in 1 took place, affording an amidomethylene-bridged dititanium dinitrogen complex [{(acriPNP)Ti}2(µ-η1:η2-N2){µ-η1:η2-CH2N(p-MeOC6H4)}] (3), which upon reaction with another equivalent of p-methoxyphenyl isocyanide at room temperature gave an amidomethylene/nitrido/carbodiimido complex [(acriPNP)Ti(N═C═NR)(µ-N)(µ-η1:η2-CH2NR)Ti(acriPNP)] (4) through N2 cleavage and N═C bond formation. Further reaction of 4 with 1 equiv of p-methoxyphenyl isocyanide led to an unprecedented four-component (carbodiimido, nitrido, isocyanide, and amidomethylene) coupling, yielding an amidoamidinatoguanidinate complex [{(acriPNP)Ti}2{NC(═NR)NC(═NR)CH2NR}] (5), which on reaction with another equivalent of p-methoxyphenyl isocyanide afforded the isocyanide-coordinated analogue 2. The reaction of 1 with 2-naphthyl isocyanide also took place in a similar multicoupling fashion. Moreover, the cross-coupling reactions of the p-methoxyphenyl isocyanide-derived amidomethylene/nitrido/carbodiimido complex 4 with 2-naphthyl isocyanide, cyclohexyl isocyanide, and tert-butyl isocyanide were also achieved, which afforded the corresponding amidoamidinatoguanidinate products consisting of two different isocyanides. Density functional theory (DFT) calculations further elucidated the mechanistic details.

4.
Curr Mol Med ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38500285

RESUMO

INTRODUCTION: Skeletal muscle degeneration is a common effect of chronic muscle injuries, including fibrosis and fatty infiltration, which is the replacement of preexisting parenchymal tissue by extracellular matrix proteins and abnormal invasive growth of fibroblasts and adipocytes. METHOD: This remodeling limits muscle function and strength, eventually leading to reduced quality of life for those affected. Chemokines play a major role in the regulation of immunocyte migration, inflammation, and tissue remodeling and are implicated in various fibrotic and degenerative diseases. In this study, we aimed to investigate the role of the B-cell chemokine CXCL13 in the gastrocnemius muscle of the Achilles tendon rupture model mouse. We hypothesize that CXCL13 may promote fibrosis and aggravate skeletal muscle degeneration. We performed RNA sequencing and bioinformatics analysis of gastrocnemius muscle from normal and model mice to identify differentially expressed genes and signal pathways related to skeletal muscle degeneration and fibrosis. RESULTS: Our results show that CXCL13 is highly expressed in chronically degenerating skeletal muscle. Furthermore, CXCL13-neutralising antibodies with therapeutic potential were observed to inhibit fibrosis and adipogenesis in vivo and in vitro. CONCLUSION: Our study reveals the underlying therapeutic implications of CXCL13 inhibition for clinical intervention in skeletal muscle degeneration, thereby improving patient prognosis.

5.
Langmuir ; 40(13): 6962-6970, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38523302

RESUMO

It is critical to remove organic contaminants from wastewater released by the printing and dyeing industry for addressing water pollution issue. Therefore, the fabrication of new adsorbents with excellent removal efficiencies is an urgent task. A composite of MIL-101 partially functionalized with -SO3H (MIL-101-SO3H) and graphene oxide (GO) was prepared by assembling MIL-101-SO3H truncated octahedrons on the GO framework. The synthesized MIL-101-SO3H@GO has a superior adsorption efficiency for anionic azo dyes. The maximum adsorption capacities of MIL-101-SO3H@GO-1 for Congo red, methyl orange, acid orange 7, and acid orange G reached 2711.3, 818.8, 551.2, and 319.8 mg/g, respectively, which are considerably higher than those obtained using unmodified MIL-101. This is because additional interactions that promote azo dye adsorption, such as hydrogen bonding between the dye and the sulfonic acid groups of MIL-101-SO3H or the carboxyl groups of GO, were induced, and agglomerate pores that accommodated the dye were formed in the composite. The ultrahigh removal efficiency of the composite for azo dyes is mainly driven by hydrogen bonding, electrostatic interactions, π-π stacking between the MIL-101-SO3H@GO and dye molecules, synergistic interactions at the interface of GO and MIL-101-SO3H microcrystals, and the pore-filling effect. Understanding these driving forces for dye adsorption can contribute to the development of sustainable and functionally modified metal-organic framework composite adsorbents.

6.
Anal Biochem ; 690: 115512, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38527608

RESUMO

A self-signal electrochemical identification interface was prepared for the determination of circulating tumor DNA (ctDNA) in peripheral blood based on poly-xanthurenic acid (PXTA) assembled on black phosphorus nanosheets (BPNSs) acquired through simple ultrasonication method. The BPNSs with large surface area could be integrated with the xanthurenic acid (XTA) monomers by right of physisorption, and hence improved the electropolymerization efficiency and was beneficial to the enlargement of the signal response of PXTA. The assembled PXTA/BPNSs composite with attractive electrochemical activity was adopted as a platform for the recognition of DNA immobilization and hybridization. The probe ssDNA was covalently fixed onto the PXTA/BPNSs composite with plentiful carboxyl groups through the terminate free amines of DNA probes by use of the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydrosulfosuccinimide cross-linking reaction, accompanied with the decline of the self-signal response. When the hybridization between the probe ssDNA and the target DNA was accomplished, the self-signal response of the composite interface reproduced by virtue of the shaping of helix construction. The determination limit of the assembled DNA identification interface was 2.1 × 10-19 mol/L, and the complementary target DNA concentrations varied from 1.0 × 10-18 mol/L to 1.0 × 10-12 mol/L. The DNA identification platform displayed magnificent sensitivity, specificity and stability, and was efficaciously implemented to the mensuration of ctDNA derived from colorectal cancer.

7.
Eur J Nutr ; 63(4): 1329-1338, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38413484

RESUMO

PURPOSE: The aim was to study the association between dietary intake of B vitamins in childhood and the risk of islet autoimmunity (IA) and progression to type 1 diabetes (T1D) by the age of 10 years. METHODS: We followed 8500 T1D-susceptible children born in the U.S., Finland, Sweden, and Germany in 2004 -2010 from the Environmental Determinants of Diabetes in the Young (TEDDY) study, which is a prospective observational birth cohort. Dietary intake of seven B vitamins was calculated from foods and dietary supplements based on 24-h recall at 3 months and 3-day food records collected regularly from 6 months to 10 years of age. Cox proportional hazard models were adjusted for energy, HLA-genotype, first-degree relative with T1D, sex, and country. RESULTS: A total of 778 (9.2) children developed at least one autoantibody (any IA), and 335 (3.9%) developed multiple autoantibodies. 280 (3.3%) children had IAA and 319 (3.8%) GADA as the first autoantibody. 344 (44%) children with IA progressed to T1D. We observed that higher intake of niacin was associated with a decreased risk of developing multiple autoantibodies (HR 0.95; 95% CI 0.92, 0.98) per 1 mg/1000 kcal in niacin intake. Higher intake of pyridoxine (HR 0.66; 95% CI 0.46, 0.96) and vitamin B12 (HR 0.87; 95% CI 0.77, 0.97) was associated with a decreased risk of IAA-first autoimmunity. Higher intake of riboflavin (HR 1.38; 95% CI 1.05, 1.80) was associated with an increased risk of GADA-first autoimmunity. There were no associations between any of the B vitamins and the outcomes "any IA" and progression from IA to T1D.  CONCLUSION: In this multinational, prospective birth cohort of children with genetic susceptibility to T1D, we observed some direct and inverse associations between different B vitamins and risk of IA.


Assuntos
Autoanticorpos , Autoimunidade , Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Complexo Vitamínico B , Humanos , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/epidemiologia , Masculino , Feminino , Complexo Vitamínico B/administração & dosagem , Estudos Prospectivos , Criança , Pré-Escolar , Lactente , Ilhotas Pancreáticas/imunologia , Autoanticorpos/sangue , Fatores de Risco , Dieta/métodos , Dieta/estatística & dados numéricos , Modelos de Riscos Proporcionais , Estados Unidos/epidemiologia , Finlândia/epidemiologia , Suécia/epidemiologia , Alemanha/epidemiologia , Suplementos Nutricionais , Coorte de Nascimento , Progressão da Doença
8.
Eur J Clin Nutr ; 78(4): 344-350, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38172348

RESUMO

BACKGROUND: Outliers can influence regression model parameters and change the direction of the estimated effect, over-estimating or under-estimating the strength of the association between a response variable and an exposure of interest. Identifying visit-level outliers from longitudinal data with continuous time-dependent covariates is important when the distribution of such variable is highly skewed. OBJECTIVES: The primary objective was to identify potential outliers at follow-up visits using interquartile range (IQR) statistic and assess their influence on estimated Cox regression parameters. METHODS: Study was motivated by a large TEDDY dietary longitudinal and time-to-event data with a continuous time-varying vitamin B12 intake as the exposure of interest and development of Islet Autoimmunity (IA) as the response variable. An IQR algorithm was applied to the TEDDY dataset to detect potential outliers at each visit. To assess the impact of detected outliers, data were analyzed using the extended time-dependent Cox model with robust sandwich estimator. Partial residual diagnostic plots were examined for highly influential outliers. RESULTS: Extreme vitamin B12 observations that were cases of IA had a stronger influence on the Cox regression model than non-cases. Identified outliers changed the direction of hazard ratios, standard errors, or the strength of association with the risk of developing IA. CONCLUSION: At the exploratory data analysis stage, the IQR algorithm can be used as a data quality control tool to identify potential outliers at the visit level, which can be further investigated.


Assuntos
Confiabilidade dos Dados , Dieta , Humanos , Vitaminas
9.
Am J Clin Nutr ; 118(6): 1099-1105, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38044022

RESUMO

BACKGROUND: Higher gluten intake in childhood is associated with increased incidence of celiac disease autoimmunity (CDA) and celiac disease. It remains to be studied whether different dietary patterns independent of gluten intake contribute to the incidence. OBJECTIVES: This study aimed to explore associations of dietary patterns by age 2 y with risk of CDA and celiac disease in genetically susceptible children. METHODS: Data was used from 6726 participants at genetic risk of type 1 diabetes and celiac disease enrolled in the observational cohort, The Environmental Determinants of Diabetes in the Young (TEDDY) study. Children were annually screened for tissue transglutaminase autoantibodies (tTGAs) from age 2 y. Principal component analysis extracted dietary patterns, based on intake of 27 food groups assessed by 3-d food records at age 9 to 24 mo. The primary outcome was CDA (i.e., persistently tTGA-positive in at least 2 consecutive samples), and the secondary outcome was celiac disease. During follow-up to mean age 11.0 (standard deviation 3.6) y, 1296 (19.3%) children developed CDA, and 529 (7.9%) were diagnosed with celiac disease. Associations of adherence to dietary patterns (per 5-unit increase) with the study outcomes were estimated by Cox regression models adjusted for risk factors including gluten intake. RESULTS: At age 9 mo, a dietary pattern higher in the food groups vegetable fats and milk was associated with reduced risk of CDA (hazard ratio [HR]: 0.88; 95% confidence interval [CI]: 0.79, 0.98; P = 0.02). At 24 mo, a dietary pattern higher in the food groups wheat, vegetable fats, and juices, and lower in milk, meat, and oats at age 24 mo was associated with increased risk of CDA (HR: 1.18; 95% CI: 1.05, 1.33; P < 0.001) and celiac disease (HR: 1.24; 95% CI: 1.03, 1.50; P = 0.03). CONCLUSIONS: Dietary patterns in early childhood are associated with risk of CDA and celiac disease in genetically predisposed children, independent of gluten intake.


Assuntos
Doença Celíaca , Criança , Humanos , Pré-Escolar , Adolescente , Adulto Jovem , Adulto , Lactente , Doença Celíaca/etiologia , Autoimunidade , Transglutaminases/genética , Autoanticorpos/genética , Predisposição Genética para Doença , Glutens/efeitos adversos
10.
Angew Chem Int Ed Engl ; 62(52): e202314832, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37946607

RESUMO

The Stille cross-coupling reaction is one of the most common strategies for the construction of C-C bonds. Despite notable strides in the advancement of the Stille reaction, persistent challenges persist in hindering its greener evolution. These challenges encompass multiple facets, such as the high cost of precious metals and ligands, the demand for various additives, and the slow reaction rate. In comparison to the dominant palladium-catalysed Stille reactions, cost-effective nickel-catalysed systems lag behind, and enantioconvergent Stille reactions of racemic stannanes remain undeveloped. Herein, we present a pioneering instance of nickel-catalysed enantioconvergent Stille cross-coupling reactions of racemic stannane reagents, resulting in the formation of C-C bonds in good to high yields with excellent stereoselectivity. This strategy provides a practical, scalable, and operationally straightforward method for the synthesis of C(sp3 )-C(sp3 ), C(sp3 )-C(sp2 ), and C(sp3 )-C(sp) bonds under exceptionally mild conditions (without additives and bases, ambient temperature). The innovative use of synergistic photoredox/nickel catalysis enables a novel single-electron transmetalation process of stannane reagents, providing a new research paradigm of Stille reactions.

11.
Chem Sci ; 14(44): 12676-12683, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38020394

RESUMO

An unprecedented nickel-catalysed enantioselective hydromonofluoromethylation of 1,3-enynes is developed, allowing the diverse access to monofluoromethyl-tethered axially chiral allenes, including the challenging deuterated monofluoromethyl (CD2F)-tethered ones that are otherwise inaccessible. It represents the first asymmetric 1,4-hydrofunctionalization of 1,3-enynes using low-cost asymmetric nickel catalysis, thus opening a new avenue for the activation of 1,3-enynes in reaction development. The utility is further verified by its broad substrate scope, good functionality tolerance, mild conditions, and diversified product elaborations toward other valuable fluorinated structures. Mechanistic experiments and DFT calculations provide insights into the reaction mechanism and the origin of the enantioselectivity.

12.
J Am Chem Soc ; 145(41): 22803-22813, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37797654

RESUMO

The direct use of dinitrogen (N2) as a building block for the synthesis of NN-containing organic compounds is of fundamental interest and practical importance but has remained a formidable challenge to date. Here, we report an unprecedented 1,4-conjugate (aza-Michael) addition of N2 to α,ß-unsaturated carbonyl compounds in a dititanium framework. The resulting hydrazinopropenolate products could be easily converted to diverse NN-containing organic compounds such as ß-hydrazine-functionalized esters and amides, pyrazolidinones, and pyrazolines depending on the types of Michael acceptors through protonation with MeOH. Further transformations of a hydrazinopropenolate titanium complex through C-C and N-C bond formations with electrophiles such as CO2 and benzaldehyde have also been achieved. The mechanistic details of the N2 addition reaction have been elucidated by computational studies, revealing the importance of redox-active metal centers in this event. This work showcases the potential of using N2 as a building block for the synthesis of NN-containing organic compounds through activation and functionalization in a molecular metal framework.

13.
Sci Adv ; 9(37): eadj2486, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37703379

RESUMO

The Wittig reaction, which is one of the most effective methods for synthesizing alkenes from carbonyl compounds, generally gives thermodynamically stable E-alkenes, and synthesis of trisubstituted Z-alkenes from ketones presents notable challenges. Here, we report what we refer to as Wittig/B─H insertion reactions, which innovatively combine a Wittig reaction with carbene insertion into a B─H bond and constitute a promising method for the synthesis of thermodynamically unstable trisubstituted Z-boryl alkenes. Combined with the easy transformations of boryl group, this methodology provides efficient access to a variety of previously unavailable trisubstituted Z-alkenes and thus provides a platform for discovery of pharmaceuticals. The unique Z-selectivity of the reaction is determined by the maximum overlap of the orbitals between the B─H bond of the borane adduct and the alkylidene carbene intermediate in the transition state.

14.
Diabetes Care ; 46(10): 1839-1847, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37579501

RESUMO

OBJECTIVE: To study the interaction among HLA genotype, early probiotic exposure, and timing of complementary foods in relation to risk of islet autoimmunity (IA). RESEARCH DESIGN AND METHODS: The Environmental Determinants of Diabetes in the Young (TEDDY) study prospectively follows 8,676 children with increased genetic risk of type 1 diabetes. We used a Cox proportional hazards regression model adjusting for potential confounders to study early feeding and the risk of IA in a sample of 7,770 children. RESULTS: Any solid food introduced early (<6 months) was associated with increased risk of IA if the child had the HLA DR3/4 genotype and no probiotic exposure during the 1st year of life. Rice introduced at 4-5.9 months compared with later in the U.S. was associated with an increased risk of IA. CONCLUSIONS: Timing of solid food introduction, including rice, may be associated with IA in children with the HLA DR3/4 genotype not exposed to probiotics. The microbiome composition under these exposure combinations requires further study.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Humanos , Lactente , Autoanticorpos/genética , Autoimunidade/genética , Predisposição Genética para Doença , Genótipo , Antígeno HLA-DR3/genética , Fatores de Risco
15.
Pediatr Diabetes ; 20232023.
Artigo em Inglês | MEDLINE | ID: mdl-37614409

RESUMO

Background/Objective: Growth and obesity have been associated with increased risk of islet autoimmunity (IA) and progression to type 1 diabetes. We aimed to estimate the effect of energy-yielding macronutrient intake on the development of IA through BMI. Research Design and Methods: Genetically at-risk children (n = 5,084) in Finland, Germany, Sweden, and the USA, who were autoantibody negative at 2 years of age, were followed to the age of 8 years, with anthropometric measurements and 3-day food records collected biannually. Of these, 495 (9.7%) children developed IA. Mediation analysis for time-varying covariates (BMI z-score) and exposure (energy intake) was conducted. Cox proportional hazard method was used in sensitivity analysis. Results: We found an indirect effect of total energy intake (estimates: indirect effect 0.13 [0.05, 0.21]) and energy from protein (estimates: indirect effect 0.06 [0.02, 0.11]), fat (estimates: indirect effect 0.03 [0.01, 0.05]), and carbohydrates (estimates: indirect effect 0.02 [0.00, 0.04]) (kcal/day) on the development of IA. A direct effect was found for protein, expressed both as kcal/day (estimates: direct effect 1.09 [0.35, 1.56]) and energy percentage (estimates: direct effect 72.8 [3.0, 98.0]) and the development of GAD autoantibodies (GADA). In the sensitivity analysis, energy from protein (kcal/day) was associated with increased risk for GADA, hazard ratio 1.24 (95% CI: 1.09, 1.53), p = 0.042. Conclusions: This study confirms that higher total energy intake is associated with higher BMI, which leads to higher risk of the development of IA. A diet with larger proportion of energy from protein has a direct effect on the development of GADA.


Assuntos
Autoimunidade , Análise de Mediação , Criança , Humanos , Índice de Massa Corporal , Ingestão de Alimentos , Ingestão de Energia , Autoanticorpos
16.
Diabetes Care ; 46(7): 1409-1416, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37141102

RESUMO

OBJECTIVE: This study investigated physical activity and its association with the development of islet autoimmunity and type 1 diabetes in genetically at-risk children aged 5-15 years. RESEARCH DESIGN AND METHODS: As part of the longitudinal Environmental Determinants of Diabetes in the Young (TEDDY) study, annual assessment of activity using accelerometry was conducted from age 5 years. Time-to-event analyses using Cox proportional hazard models were used to assess the association between time spent in moderate to vigorous physical activity per day and the appearance of one or several autoantibodies and progression to type 1 diabetes in three risk groups: 1) 3,869 islet autoantibody (IA)-negative children, of whom 157 became single IA positive; 2) 302 single IA-positive children, of whom 73 became multiple IA positive; and 3) 294 multiple IA-positive children, of whom 148 developed type 1 diabetes. RESULTS: No significant association was found in risk group 1 or risk group 2. A significant association was seen in risk group 3 (hazard ratio 0.920 [95% CI 0.856, 0.988] per 10-min increase; P = 0.021), particularly when glutamate decarboxylase autoantibody was the first autoantibody (hazard ratio 0.883 [95% CI 0.783, 0.996] per 10-min increase; P = 0.043). CONCLUSIONS: More daily minutes spent in moderate to vigorous physical activity was associated with a reduced risk of progression to type 1 diabetes in children aged 5-15 years who had developed multiple IAs.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Criança , Humanos , Lactente , Pré-Escolar , Adolescente , Diabetes Mellitus Tipo 1/epidemiologia , Autoimunidade , Autoanticorpos , Exercício Físico
17.
Science ; 380(6645): 639-644, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37167386

RESUMO

Regiocontrol in traditional cycloaddition reactions between unsaturated carbon compounds is often challenging. The increasing focus in modern medicinal chemistry on benzocyclobutene (BCB) scaffolds indicates the need for alternative, more selective routes to diverse rigid carbocycles rich in C(sp3) character. Here, we report a palladium-catalyzed double C-H activation of two adjacent methylene units in carboxylic acids, enabled by bidentate amide-pyridone ligands, to achieve a regio-controllable synthesis of BCBs through a formal [2+2] cycloaddition involving σ bonds only (two C-H bonds and two aryl-halogen bonds). A wide range of cyclic and acyclic aliphatic acids, as well as dihaloheteroarenes, are compatible, generating diversely functionalized BCBs and hetero-BCBs present in drug molecules and bioactive natural products.

18.
Exp Mol Med ; 55(5): 1013-1022, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37121976

RESUMO

The serum glycoprotein leucine-rich ɑ-2-glycoprotein 1 (LRG1), primarily produced by hepatocytes and neutrophils, is a multifunctional protein that modulates various signaling cascades, mainly TGFß signaling. Serum LRG1 and neutrophil-derived LRG1 have different molecular weights due to differences in glycosylation, but the impact of the differential glycan composition in LRG1 on its cellular function is largely unknown. We previously reported that LRG1 can promote both angiogenic and neurotrophic processes under hyperglycemic conditions by interacting with LPHN2. Here, we determined the crystal structure of LRG1, identifying the horseshoe-like solenoid structure of LRG1 and its four N-glycosylation sites. In addition, our biochemical and cell-biological analyses found that the deglycosylation of LRG1, particularly the removal of glycans on N325, is critical for the high-affinity binding of LRG1 to LPHN2 and thus promotes LRG1/LPHN2-mediated angiogenic and neurotrophic processes in mouse tissue explants, even under normal glucose conditions. Moreover, the intracavernous administration of deglycosylated LRG1 in a diabetic mouse model ameliorated vascular and neurological abnormalities and restored erectile function. Collectively, these data indicate a novel role of LRG1 glycans as molecular switches that can tune the range of LRG1's cellular functions, particularly the LRG1/LPHN2 signaling axis.


Assuntos
Glicoproteínas , Transdução de Sinais , Animais , Masculino , Camundongos , Modelos Animais de Doenças , Glicoproteínas/metabolismo , Glicosilação
19.
Diabetes Care ; 46(5): 1014-1018, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36867433

RESUMO

OBJECTIVE: To examine whether iron intake and genetically determined iron overload interact in predisposing to the development of childhood islet autoimmunity (IA) and type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: In The Environmental Determinants of Diabetes in the Young (TEDDY) study, 7,770 genetically high-risk children were followed from birth until the development of IA and progression to T1D. Exposures included energy-adjusted iron intake in the first 3 years of life and a genetic risk score (GRS) for increased circulating iron. RESULTS: We found a U-shaped association between iron intake and risk of GAD antibody as the first autoantibody. In children with GRS ≥2 iron risk alleles, high iron intake was associated with an increased risk of IA, with insulin as first autoantibody (adjusted hazard ratio 1.71 [95% CI 1.14; 2.58]) compared with moderate iron intake. CONCLUSIONS: Iron intake may alter the risk of IA in children with high-risk HLA haplogenotypes.


Assuntos
Diabetes Mellitus Tipo 1 , Sobrecarga de Ferro , Ilhotas Pancreáticas , Criança , Humanos , Lactente , Autoimunidade/genética , Ferro da Dieta , Ferro , Fatores de Risco , Autoanticorpos/genética , Sobrecarga de Ferro/genética , Predisposição Genética para Doença
20.
Bioelectrochemistry ; 148: 108231, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36166896

RESUMO

A self-signal electrochemical sensing platform was constructed for direct recognition of circulating tumor DNA (ctDNA) employing black phosphorous nanosheets (BPNS) assembled with flavin adenine dinucleotide (FAD) prepared by ultrasonication approach. FAD provided a highly efficient and stable dispersing medium for acquiring highly dispersed BPNS in aqueous phase. The obtained FAD/BPNS nanocomposite exhibited favorable electrochemical redox activity and was utilized as the interface for the immobilization and hybridization of DNA. The amine-terminated probe ssDNA was covalently assembled onto the FAD/BPNS nanocomposite with plentiful phosphonate groups accompanied by the decrease of the self-signal. The self-redox signal of the nanointerface regenerated after the probe hybridized with the complementary sequence as a result of DNA transformation. Electrochemical response enhanced with complementary DNA concentration from 1.0 × 10-18 to 1.0 × 10-8 mol/L with a detection limit of 2.6 × 10-19 mol/L. The DNA determination platform revealed outstanding sensitivity, specificity and stableness, and was successfully employed in the detection of ctDNA associated with colorectal cancer. The developed biosensing strategy is simple to accomplish and has the potency for the application for diverse morbific gene without sophisticated label procedure.


Assuntos
Técnicas Biossensoriais , DNA Tumoral Circulante , Organofosfonatos , Aminas , Técnicas Biossensoriais/métodos , DNA/genética , DNA Complementar , Técnicas Eletroquímicas/métodos , Flavina-Adenina Dinucleotídeo , Fósforo
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