Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Immunity ; 57(6): 1289-1305.e9, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38772366

RESUMO

Adipose tissue group 2 innate lymphoid cells (ILC2s) help maintain metabolic homeostasis by sustaining type 2 immunity and promoting adipose beiging. Although impairment of the ILC2 compartment contributes to obesity-associated insulin resistance, the underlying mechanisms have not been elucidated. Here, we found that ILC2s in obese mice and humans exhibited impaired liver kinase B1 (LKB1) activation. Genetic ablation of LKB1 disrupted ILC2 mitochondrial metabolism and suppressed ILC2 responses, resulting in exacerbated insulin resistance. Mechanistically, LKB1 deficiency induced aberrant PD-1 expression through activation of NFAT, which in turn enhanced mitophagy by suppressing Bcl-xL expression. Blockade of PD-1 restored the normal functions of ILC2s and reversed obesity-induced insulin resistance in mice. Collectively, these data present the LKB1-PD-1 axis as a promising therapeutic target for the treatment of metabolic disease.


Assuntos
Tecido Adiposo , Homeostase , Resistência à Insulina , Linfócitos , Mitocôndrias , Obesidade , Receptor de Morte Celular Programada 1 , Proteínas Serina-Treonina Quinases , Animais , Resistência à Insulina/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Camundongos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Mitocôndrias/metabolismo , Humanos , Tecido Adiposo/metabolismo , Tecido Adiposo/imunologia , Obesidade/imunologia , Obesidade/metabolismo , Linfócitos/imunologia , Linfócitos/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Imunidade Inata , Masculino , Mitofagia/imunologia , Quinases Proteína-Quinases Ativadas por AMP
2.
Langmuir ; 40(13): 6816-6823, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38502787

RESUMO

Efficient and stable ocular lubrication is pivotal in safeguarding eye tissues from wear, especially under repetitive strain due to frequent blinking. Hydrogels have been reported to possess adjustable mechanical properties, biocompatibility, durability, and elevated water content and extensive utilization in medical fields. In this work, a kind of visible photo-cross-linking poly(vinylpyrrolidone) (PVP) hydrogel was designed and synthesized using 1-vinyl-2-pyrrolidone (NVP) and poly(ethylene glycol) diacrylate (PEGDA). To optimize the structure and improve the lubrication performance of hydrogels, we prepared and investigated glycerol ethoxylate (GE)-introduced composite hydrogels (GE/PVP). The results show that the addition of 3 wt % GE helped the hydrogel to form a uniform and dense porous matrix and reduce the frictional coefficient (COF) by over 50%, achieving superlubricity (COF ≈ 0.005). However, with the excessive increase of GE (6 wt %), the structure of the hydrogel is destroyed, inducing pore walls to thin and expand. After that, a lubrication mechanism of the GE/PVP composite hydrogel was proposed, in which the addition of GE reduced the surface tension of the hydrogel, enhanced the hydration ability of the hydrogel, and thus decreased the friction between sliding surfaces. Besides, the cytotoxicity tests show that the composite hydrogels possess good biocompatibility. Overall, the as-synthesized hydrogels hold great potential as lubricating medium for use in ocular applications.

3.
Diabetes Metab Res Rev ; 39(4): e3620, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36738300

RESUMO

AIMS: It is acknowledged that aberrant liver immunity contributes to the development of type 2 diabetes mellitus (T2DM). Mucosal-associated invariant T (MAIT) cells, an innate-like T-cell subset, are enriched in the human liver. Nevertheless, the characterisation and potential role of hepatic MAIT cells in T2DM remain unclear. MATERIALS AND METHODS: Fourteen newly diagnosed T2DM subjects and 15 controls received liver biopsy. The frequency and cytokine production of MAIT cells were analysed by flow cytometry. The expression of genes involved in glucose metabolism was determined in HepG2 cells co-cultured with hepatic MAIT cells. RESULTS: Compared with controls, hepatic MAIT cell frequency was significantly increased in T2DM patients (24.66% vs. 14.61%, p = 0.001). There were more MAIT cells producing interferon-γ (IFN-γ, 60.49% vs. 33.33%, p = 0.021) and tumour necrosis factor-α (TNF-α, 46.84% vs. 5.91%, p = 0.021) in T2DM than in controls, whereas their production of interleukin 17 (IL-17) was comparable (15.25% vs. 4.55%, p = 0.054). Notably, an IFN-γ+ TNF-α+ IL-17+/- producing MAIT cell subset was focussed, which showed an elevated proportion in T2DM (42.66% vs. 5.85%, p = 0.021) and positively correlated with plasma glucose levels. A co-culture experiment further indicated that hepatic MAIT cells from T2DM upregulated the gene expression of pyruvate carboxylase, a key molecule involved in gluconeogenesis, in HepG2 cells, and this response was blocked with neutralising antibodies against IFN-γ and TNF-α. CONCLUSIONS: Our data implicate an increased Th1-like MAIT cell subset in the liver of newly diagnosed T2DM subjects, which induces hyperglycaemia by promoting hepatic gluconeogenesis. It provides novel insights into the immune regulation of metabolic homoeostasis. CLINICAL TRIAL REGISTRATION NUMBER: NCT03296605 (registered at www. CLINICALTRIALS: gov on 12 October 2018).


Assuntos
Diabetes Mellitus Tipo 2 , Células T Invariantes Associadas à Mucosa , Humanos , Células T Invariantes Associadas à Mucosa/fisiologia , Interleucina-17 , Fator de Necrose Tumoral alfa , Gluconeogênese , Fígado
4.
Mol Med ; 28(1): 18, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123388

RESUMO

BACKGROUND: Although type 1 diabetes (T1D) is typically described as a T cell-mediated autoimmune disease, increasing evidence for a role of B cells has emerged. However, the pivotal disease-relevant B cell subset and its contribution to islet autoimmunity remain elusive. METHODS: The frequencies and phenotypic characteristics of circulating B cell subsets were analyzed using flow cytometry in individuals with new-onset T1D, long-term T1D, type 2 diabetes, and nondiabetic controls, and also in a prospective cohort of patients receiving mesenchymal stromal cell (MSC) transplantation. NOD mice and adoptive transfer assay were used to dissect the role of the certain B cell subset in disease progression. An in-vitro coculture system of islets with immune cells was established to examine the response against islets and the underlying mechanisms. RESULTS: We identified that plasmablasts, a B cell subset at the antibody-secreting stage, were significantly increased and correlated with the deterioration of beta cell function in patients with new-onset T1D. Further, a fall of plasmablast number was associated with the preservation of beta cell function in patients who received MSC transplantation after 3 months of follow-up. Meanwhile, a gradual increase of plasmablasts in pancreatic lymph nodes during the natural progression of insulitis was observed in non-obese diabetic (NOD) mice; adoptive transfer of plasmablasts together with T cells from NOD mice accelerated diabetes onset in NOD/SCID recipients. CONCLUSIONS: Our study revealed that plasmablasts may function as antigen-presenting cells and promote the activation and proinflammatory response of CD4+ T cells, further contributing to the T cell-mediated beta cell destruction. Our results provide insights into the pathogenic role of plasmablasts in islet autoimmunity and may offer new translational strategies for inhibiting T1D development.


Assuntos
Diabetes Mellitus Tipo 1/etiologia , Diabetes Mellitus Tipo 1/metabolismo , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Biomarcadores , Estudos de Casos e Controles , Diabetes Mellitus Tipo 1/diagnóstico , Modelos Animais de Doenças , Suscetibilidade a Doenças/imunologia , Feminino , Humanos , Imuno-Histoquímica , Imunofenotipagem , Células Secretoras de Insulina/patologia , Ativação Linfocitária , Masculino , Camundongos SCID
5.
Environ Res ; 215(Pt 2): 114373, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36165871

RESUMO

Despite growing concerns over mercury (Hg) accumulation in birds in recent decades, little is known about Hg exposure in nocturnal migratory birds. Here, total mercury (THg) and methylmercury (MeHg) were detected in the feathers of nocturnal migratory birds (n = 286, belonging to 46 species) passing through Mount Ailao in Southwest China. The stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) were also determined to clarify the effects of trophic position, foraging guild, and foraging behavior on Hg bioaccumulation. Our results show that the THg and MeHg concentrations varied by two orders of magnitude among all nocturnal migratory birds investigated, with the lowest values (THg: 0.056 mg kg-1; MeHg: 0.038 mg kg-1) in the Asian koel (Eudynamys scolopaceus) and the highest (THg: 12 mg kg-1; MeHg: 7.8 mg kg-1) in the hair-crested drongo (Dicrurus hottentottus). Waterbirds showed higher δ15N values and higher THg and MeHg concentrations than songbirds, and the Hg concentrations in piscivorous species were significantly higher than those in herbivores, omnivores, and insectivores. Significant effects of foraging guilds (Kruskal-Wallis one-way ANOVA, p < 0.001) and foraging behaviors (Kruskal-Wallis one-way ANOVA, p < 0.001) on the Hg concentrations in migratory bird feathers were detected. A risk assessment indicated that approximately 7.0% of individuals were at moderate (2.4-5.0 mg kg-1) to high (>5.0 mg kg-1) risk of Hg exposure, and were therefore vulnerable to adverse physiological and behavioral effects. A long-term monitoring campaign during the migratory period is highly recommended to better understand the bioaccumulation of Hg in these nocturnal migratory bird populations over time.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Aves Canoras , Poluentes Químicos da Água , Animais , Carbono , China , Monitoramento Ambiental , Mercúrio/análise , Nitrogênio , Poluentes Químicos da Água/análise
6.
Ann Nutr Metab ; 77(3): 168-177, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34340237

RESUMO

BACKGROUND/AIMS: Roux-en-Y gastric bypass (RYGB) is one of the most effective therapies for morbid obesity, yet some patients who have taken the surgery still undergo insufficient weight loss. Visceral adiposity index (VAI), lipid accumulation product (LAP), body adiposity index (BAI), and cardiometabolic index (CMI) have been regarded as clinical indicators of adiposity phenotypes that associated closely with obesity-related metabolic diseases. However, no studies have evaluated the relationship between these indexes and weight loss after bariatric surgery. In this prospective study, we aimed to evaluate whether VAI, LAP, BAI, and CMI would predict postoperative weight loss outcomes after RYGB. METHODS: This study included 38 men and 67 women who have undergone RYGB between January 2017 and May 2018 and recorded their %TWL (percent of total weight loss), %EBMIL (percent of excess body mass index loss), %EWL (percent of excess weight loss), anthropometric indices, and biochemical parameters before and 12 months after the surgery. In addition, VAI, LAP, BAI, and CMI were measured with anthropometric measures or lipid profiles using related equations and analyzed with metabolic characteristics. RESULTS: Subjects with lower BAI (<32.54 in men and 37.39 in women) displayed higher %EBMIL and %EWL 12 months after surgery. BAI was independently associated with %EWL 12 months after surgery in both men and women (both p < 0.05). The area under the receiver operating characteristic curve for BAI was significantly higher (0.773 in men and 0.818 in women) than VAI, LAP, and CMI. CONCLUSIONS: BAI serves as a reliable surrogate marker of the weight loss outcome after RYGB. The predictivity of adiposity indexes in beneficial outcomes after weight loss therapies is of important referential value for the implementation and optimization of individualized and refined weight loss treatments for obese patients.


Assuntos
Adiposidade , Derivação Gástrica , Redução de Peso , Índice de Massa Corporal , Feminino , Humanos , Masculino , Obesidade Abdominal , Obesidade Mórbida/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
7.
Langmuir ; 36(45): 13477-13484, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33136405

RESUMO

Phospholipids, as essential components in joint synovial fluid, play a dominant role in joint lubrication. In this study, atomic force microscopy was used to evaluate the normal and shear forces between two surfaces bearing three types of phospholipids with different acyl chain lengths, which were pre-adsorbed onto silica surfaces at different temperatures (25, 45, and 60 °C). When the pre-adsorption temperature was below the phospholipid phase transition temperature (Tm), a super-low friction coefficient [1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC): 0.002; 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC): 0.007] between two opposing silica surfaces in water was achieved because of the super-low shear strength of the hydration shell and robustness of the vesicle when the load was less than the critical value (DSPC: 500 nN; DPPC: 85 nN). However, when the pre-adsorption temperature exceeded Tm, the silica surface was covered by a bilayer structure with many defects, which exhibited poor adsorption density and low bearing capacity, resulting in a relatively high friction coefficient. This study gains insights into the influence of structure and temperature on the lubrication mechanism of phospholipids as biolubricants, providing guidance for the application of artificial joint synovial fluid.

8.
Diabetes Metab Res Rev ; 35(7): e3177, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077529

RESUMO

AIMS: Diminished energy turnover of skeletal muscle is involved in the development of type 2 diabetes. Intensive insulin therapy has been reported to maintain glycaemic control in newly diagnosed type 2 diabetes, while the underlying mechanism remains unclear. Herein, we aimed to characterize the contribution of muscular mitochondrial oxidative phosphorylation (OxPhos) activity to insulin-induced glycaemic control. MATERIALS AND METHODS: There were 21 drug naïve patients with type 2 diabetes receiving continuous subcutaneous insulin infusion for 7 days. Nine nondiabetics matched for age, body mass index, and physical activity were recruited as controls. We applied 31 P magnetic resonance spectroscopy to record in vivo muscular phosphocreatine (PCr) flux in controls and diabetics before and after insulin therapy. The mitochondrial OxPhos rate was calculated as ΔPCr / Δtime during the first 50 seconds after cessation of exercise. RESULTS: In drug naïve type 2 diabetes, muscular mitochondrial OxPhos rate was restored after insulin therapy. Notably, this alteration was positively associated with the improvements of 1,5-anhydroglucitol, a serum marker for glucose control over the last 1 week, as well as homeostasis model assessment of ß cell function and C-peptide/glucose ratio t0 , two indices for basal insulin secretion. Furthermore, patients with diabetes family history and more severe glucotoxicity tend to achieve greater improvement in mitochondrial function by insulin. CONCLUSIONS: This study provides evidence that intensive insulin therapy facilitates muscular energy metabolism in drug naïve type 2 diabetes. It correlates to the recovery of ß cell function, contributing to insulin-induced glucose control.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Metabolismo Energético/efeitos dos fármacos , Hipoglicemiantes/uso terapêutico , Células Secretoras de Insulina/fisiologia , Insulina/uso terapêutico , Músculo Esquelético/metabolismo , Adulto , Biomarcadores/análise , Glicemia/análise , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Feminino , Seguimentos , Humanos , Resistência à Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/efeitos dos fármacos , Prognóstico , Recuperação de Função Fisiológica
9.
Langmuir ; 35(36): 11784-11790, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31432683

RESUMO

In this study, ultralow friction coefficient (COF, µ < 0.01) was obtained through polyalkylene glycol (PAG) aqueous solutions with different molecular weights (MWs) ranging from 270 to 3930 g·mol-1 under ambient conditions. With the increase in the MWs of PAG molecules, the threshold concentration to obtain this type of superlubric behavior gradually changed from 90 to 60 wt %. This phenomenon was closely related to the interaction between PAG chains and water molecules and the state of chemical binding. In the superlubricity system, superior load-bearing capacity was achieved at optimal threshold concentrations of all PAG aqueous solutions wherein multilayered adsorption layers that consisted of fully hydrated PAG molecules were formed on the sliding solid surfaces. With respect to the concentration below the threshold value, the existence of a shearing layer was indicated to play a significant role. Thus, the synergetic effect of sufficient adsorption of molecules and the unique shear rheology of the PAG aqueous solution were essential to achieve superlubricity.

10.
J Hepatol ; 68(6): 1247-1255, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29452209

RESUMO

BACKGROUND & AIMS: Prolactin (PRL) is a multifunctional polypeptide with effects on metabolism, however, little is known about its effect on hepatic steatosis and lipid metabolism. Herein, we aimed to assess the role of PRL in the development of non-alcoholic fatty liver disease (NAFLD). METHODS: The serum PRL levels of 456 patients with NAFLD, 403 controls without NAFLD diagnosed by ultrasound, and 85 individuals with liver histology obtained during metabolic surgery (44 female and 30 male patients with NAFLD and 11 age-matched non-NAFLD female individuals) were evaluated. The expression of the gene encoding the prolactin receptor (PRLR) and signalling molecules involved in hepatic lipid metabolism were evaluated in human liver and HepG2 cells. The effects of overexpression of PRLR or fatty acid translocase (FAT)/CD36 or knockdown of PRLR on hepatic lipid metabolism were tested in free fatty acid (FFA)-treated HepG2 cells. RESULTS: Circulating PRL levels were lower in individuals with ultrasound-diagnosed NAFLD (men: 7.9 [range, 5.9-10.3] µg/L; women: 8.7 [range, 6.1-12.4] µg/L) than those with non-NAFLD (men: 9.1 [range, 6.8-13.0] µg/L, p = 0.002; women: 11.6 [range, 8.2-16.1] µg/L, p <0.001). PRL levels in patients with biopsy-proven severe hepatic steatosis were lower compared with those with mild-to-moderate hepatic steatosis in both men (8.3 [range, 5.4-9.5] µg/L vs. 9.7 [range, 7.1-12.3] µg/L, p = 0.031) and women (8.5 [range, 4.2-10.6] µg/L vs. 9.8 [range, 8.2-15.7] µg/L, p = 0.027). Furthermore, hepatic PRLR gene expression was significantly reduced in patients with NAFLD and negatively correlated with CD36 gene expression. In FFA-induced HepG2 cells, PRL treatment or PRLR overexpression significantly reduced the expression of CD36 and lipid content, effects that were abrogated after silencing of PRLR. Furthermore, overexpression of CD36 significantly reduced the PRL-mediated improvement in lipid content. CONCLUSIONS: Our results reveal a novel association between the central nervous system and the liver, whereby PRL/PRLR improved hepatic lipid accumulation via the CD36 pathway. LAY SUMMARY: Our clinical study suggests a negative association between prolactin (PRL)/prolactin receptor (PRLR) and the presence of non-alcoholic fatty liver disease (NAFLD). Using cell experiments, we found that PRL ameliorates hepatic steatosis via the hepatic PRLR and fatty acid translocase (FAT)/CD36, a key transporter of free fatty acid uptake in liver. Our findings suggest a novel approach to improving NAFLD using PRL and PRLR. Clinical trial number: NCT03296605.


Assuntos
Antígenos CD36/sangue , Hepatopatia Gordurosa não Alcoólica/sangue , Prolactina/sangue , Adulto , Idoso , Antígenos CD36/genética , Estudos de Casos e Controles , Feminino , Expressão Gênica , Células Hep G2 , Humanos , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , Estudos Prospectivos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores da Prolactina/genética , Receptores da Prolactina/metabolismo , Transdução de Sinais
11.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1863(6): 595-603, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29522896

RESUMO

Erythropoietin (EPO), besides its stimulatory effect on erythropoiesis, is beneficial to insulin resistance and obesity. However, its role in hepatic steatosis remains unexplored. Activating autophagy seems a promising mechanism for improving fatty liver disease. The present study investigated the role of EPO in alleviating hepatic steatosis and sought to determine whether its function is mediated by the activation of autophagy. Here, we show that EPO decreased hepatic lipid content significantly in vivo and in vitro. Furthermore, EPO/EPO receptor (EPOR) signalling induced autophagy activation in hepatocytes as indicated by western blot assay, transmission electron microscopy, and confocal microscopy. In addition, EPO increased the co-localization of autophagosomes and cellular lipids as shown by double labelling of the autophagy marker light chain microtubule-associated protein 3 (LC3) and lipids. Importantly, suppression of autophagy by an inhibitor or small interfering RNA (siRNA) abolished the EPO-mediated alleviation hepatic steatosis in vitro. Furthermore, EPO up-regulated sirtuin 1 (SIRT1) expression, and siRNA-mediated SIRT1 silencing abrogated the EPO-induced increases in LC3 protein and deacetylation levels, thereby preventing the alleviation of hepatic steatosis. Taken together, this study revealed a new mechanism wherein EPO alleviates hepatic steatosis by activating autophagy via SIRT1-dependent deacetylation of LC3. This finding might have therapeutic value in the treatment of hepatic steatosis.


Assuntos
Autofagia , Eritropoetina/metabolismo , Fígado Gorduroso/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Sirtuína 1/metabolismo , Acetilação , Animais , Eritropoetina/genética , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Camundongos , Camundongos Obesos , Proteínas Associadas aos Microtúbulos/genética , Sirtuína 1/genética
12.
Biochim Biophys Acta Gen Subj ; 1861(7): 1801-1812, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28341485

RESUMO

BACKGROUND: Structural disruption of gut microbiota contributes to the development of non-alcoholic fatty liver disease (NAFLD) and modulating the gut microbiota represents a novel strategy for NAFLD prevention. Although previous studies have demonstrated that curcumin alleviates hepatic steatosis, its effect on the gut microbiota modulation has not been investigated. METHODS: Next generation sequencing and multivariate analysis were utilized to evaluate the structural changes of gut microbiota in a NAFLD rat model induced by high fat-diet (HFD) feeding. RESULTS: We found that curcumin attenuated hepatic ectopic fat deposition, improved intestinal barrier integrity, and alleviated metabolic endotoxemia in HFD-fed rats. More importantly, curcumin dramatically shifted the overall structure of the HFD-disrupted gut microbiota toward that of lean rats fed a normal diet and altered the gut microbial composition. The abundances of 110 operational taxonomic units (OTUs) were altered by curcumin. Seventy-six altered OTUs were significantly correlated with one or more hepatic steatosis associated parameters and designated 'functionally relevant phylotypes'. Thirty-six of the 47 functionally relevant OTUs that were positively correlated with hepatic steatosis associated parameters were reduced by curcumin. CONCLUSION: These results indicate that curcumin alleviates hepatic steatosis in part through stain-specific impacts on hepatic steatosis associated phylotypes of gut microbiota in rats. GENERAL SIGNIFICANCE: Compounds with antimicrobial activities should be further investigated as novel adjunctive therapies for NAFLD.


Assuntos
Curcumina/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Animais , Dieta Hiperlipídica , Microbioma Gastrointestinal/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Hepatopatia Gordurosa não Alcoólica/microbiologia , Ratos , Ratos Sprague-Dawley
13.
World J Microbiol Biotechnol ; 31(9): 1443-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26149956

RESUMO

Three KPC-2-producing Escherichia coli (E1, E2, and E3) were recovered from water samples of an urban river in the city of Harbin, China. Antimicrobial susceptibility was determined by broth microdilution. Molecular characterization and genetic relatedness of the isolates were determined by polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and PCR-directed phylotyping. Plasmids were analyzed by conjugation, S1-PFGE, Southern blotting and PCR-based replicon typing (PBRT). The genetic environment of the bla KPC-2 gene was determined using PCR and sequencing. PCR analyses revealed that the E1 isolate carried the bla KPC-2, bla CMY-2, bla TEM-1, bla CTX-M-14, and qnrB2 genes and belonged to sequence type ST410, phylogenetic type A; the E2 isolate was assigned to ST131-B2 and carried the bla KPC-2, bla TEM-1, bla CTX-M-3, bla DHA-1, aac(6')-Ib-cr, and qnrS1 genes; while the E3 isolate was of ST648-D and possessed bla KPC-2, bla TEM-1, bla OXA-1, bla CTX-M-15, armA, and aac(6')-Ib-cr genes. PFGE demonstrated that each of the three KPC-2-producing E. coli isolates exhibited an individual XbaI patterns. The bla KPC-2 gene was located on plasmids of 60-140 kb with IncA/C, IncN, or non-typeable replicon types. The genetic environment of bla KPC-2 of the three strains was consistent with the genetic structure of bla KPC-2 on the plasmid pKP048.


Assuntos
Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Rios/microbiologia , beta-Lactamases/genética , Antibacterianos/farmacologia , China , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana , Filogenia , Microbiologia da Água , beta-Lactamases/metabolismo
15.
Front Chem ; 12: 1417715, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38979404

RESUMO

Antimicrobial photodynamic therapy (aPDT) has emerged as a highly promising strategy for non-antibiotic treatment of infections due to its unique advantages in efficient bactericidal action and reduction of drug resistance. The natural photosensitizing properties of curcumin (Cur) are widely acknowledged; however, its limited bioavailability has impeded its practical application. In this study, we developed a nanomaterial called Cur@ZIF-8@BA by encapsulating Cur within ZIF-8 and modifying the surface with boric acid (BA). The Cur@ZIF-8@BA exhibits pH-responsive properties and enhances bacterial binding, thereby effectively promoting photodynamic therapy. Moreover, its antibacterial activity against E. coli, Staphylococcus aureus and A. baumannii is significantly increased in the presence of light compared to a dark environment. The mechanism behind this may be that BA increases the affinity of Cur@ZIF-8@BA towards bacteria, and making released Zn2+ and BA from the nanomaterial increase bacterial cell membrane permeability. This facilitates efficient delivery of Cur into bacterial cells, resulting in generation of abundant reactive oxygen species (ROS) and subsequent bactericidal activity. In conclusion, our prepared Cur@ZIF-8@BA holds great promise as a photodynamically mediated antimicrobial strategy.

16.
Int J Biol Macromol ; 274(Pt 2): 133485, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38944081

RESUMO

Thermogelling polymers with transparency, structure stability and biocompatibility are promising for biomedicine application. In this study, a thermogelling polymer P-C5PEG with tunable transparency was developed by the reaction between alternating copolymer C5PEG and chemically modified biomolecule Alg-PBA via boronic ester bonds. The sol-to-gel transition of P-C5PEG aqueous solution sensitively responded to changes in temperature, and the critical value could be adjusted between 15 and 40 °C by varying the content of C5PEG and Alg-PBA. As the weight ratio of Alg-PBA to C5PEG was over 0.3, the transparency of as-synthesized hydrogel kept above 75 % at 37 °C. Meanwhile, immersion P-C5PEG hydrogel in CaCl2 solution significantly increased its mechanical strength by 3 times due to chelation effect. The shear-resistance and self-healing properties were ensured by dynamic boronic ester bonds due to the protective effect of hydrophobic gel network. As a drug delivery, P-C5PEG hydrogel had a swelling rate of 3748.7 ± 103 % in PBS and could continuously release fluorescein sodium within 24 h. Moreover, the in vitro degradability and cytotoxicity of P-C5PEG was confirmed. Finally, the mechanisms behind the thermogelling property and tunable transparency were revealed. Overall, this thermogelling P-C5PEG polymer, with tunable transparency and thermo-responsiveness, exhibits great potential for biomedicine application.

17.
ACS Appl Mater Interfaces ; 16(1): 1675-1687, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38127457

RESUMO

The ocular environment is crucial for a biological lubrication system. An unstable condition of tear film may cause a series of ocular diseases due to serious friction, such as dry eye syndrome, which has drawn extensive attention nowadays. In this study, an in vitro biocompatible superlubricity system, containing thermogelling copolymers (PCGA-PEG-PCGA) and slow-release lubricant (PEG 300/Tween 80), was constructed. First, the sol-gel transition temperature and gel strength of PCGA-PEG-PCGA were adjusted based on the ocular environment by regulating the length of PCGA blocks. Furthermore, the copolymer hydrogel exhibited a reliable slow-release property within 10 days and showed low cytotoxicity. Then, the superlubricity (coefficient of friction of approximately 0.005) was achieved with its released PEG 300/Tween 80 aqueous solution at the sliding velocity range of 1-100 mm s-1 and pressure range of 10-22 kPa. However, the lubrication behaviors varied, while PEG 300 chains and Tween 80 micelles were demonstrated to form a multilayer and a single layer adsorption structure on the sliding surface, respectively. On the whole, the composite lubrication systems, especially the one composed of Tween 80, showed excellent tribological properties owing to the stable slow-release and full hydration effects under ocular conditions, which hold great potential for improving ocular lubrication and maintaining human visual health.


Assuntos
Lubrificantes , Polissorbatos , Humanos , Lubrificantes/química , Polietilenoglicóis/química , Polímeros
18.
Nat Commun ; 15(1): 4827, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844451

RESUMO

Adipose progenitor cells (APCs) are heterogeneous stromal cells and help to maintain metabolic homeostasis. However, the influence of obesity on human APC heterogeneity and the role of APC subpopulations on regulating glucose homeostasis remain unknown. Here, we find that APCs in human visceral adipose tissue contain four subsets. The composition and functionality of APCs are altered in patients with type 2 diabetes (T2D). CD9+CD55low APCs are the subset which is significantly increased in T2D patients. Transplantation of these cells from T2D patients into adipose tissue causes glycemic disturbance. Mechanistically, CD9+CD55low APCs promote T2D development through producing bioactive proteins to form a detrimental niche, leading to upregulation of adipocyte lipolysis. Depletion of pathogenic APCs by inducing intracellular diphtheria toxin A expression or using a hunter-killer peptide improves obesity-related glycemic disturbance. Collectively, our data provide deeper insights in human APC functionality and highlights APCs as a potential therapeutic target to combat T2D. All mice utilized in this study are male.


Assuntos
Diabetes Mellitus Tipo 2 , Glucose , Homeostase , Obesidade , Análise de Célula Única , Células-Tronco , Humanos , Animais , Análise de Célula Única/métodos , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Camundongos , Células-Tronco/metabolismo , Glucose/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Adipócitos/metabolismo , Gordura Intra-Abdominal/metabolismo , Gordura Intra-Abdominal/citologia , Tecido Adiposo/metabolismo , Tecido Adiposo/citologia , Camundongos Endogâmicos C57BL , Lipólise , Feminino , Pessoa de Meia-Idade
19.
Sci Rep ; 13(1): 13564, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37604837

RESUMO

Oxidative stress (OS), which impacts lipid metabolic reprogramming, can affect the biological activities of cancer cells. How oxidative stress and phospholipid metabolism (OSPM) influence the prognosis of pancreatic cancer (PC) needs to be elucidated. The metabolic data of 35 pancreatic tumor samples, 34 para-carcinoma samples, and 31 normal pancreatic tissues were obtained from the previously published literature. Pan-cancer samples were obtained from The Cancer Genome Atlas (TCGA). And the Gene Expression Omnibus (GEO), International Cancer Genome Consortium (ICGC), ArrayExpress, and the Genotype-Tissue Expression (GTEx) databases were searched for more PC and normal pancreatic samples. The metabolites in PC were compared with normal and para-carcinoma tissues. The characteristics of the key OSPM genes were summarized in pan-cancer. The random survival forest analysis and multivariate Cox regression analysis were utilized to construct an OSPM-related signature. Based on this signature, PC samples were divided into high- and low-risk subgroups. The dysregulations of the tumor immune microenvironment were further investigated. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was conducted to investigate the expression of genes in the signature in PC and normal tissues. The protein levels of these genes were further demonstrated. In PC, metabolomic studies revealed the alteration of PM, while transcriptomic studies showed different expressions of OSPM-related genes. Then 930 PC samples were divided into three subtypes with different prognoses, and an OSPM-related signature including eight OSPM-related genes (i.e., SLC2A1, MMP14, TOP2A, MBOAT2, ANLN, ECT2, SLC22A3, and FGD6) was developed. High- and low-risk subgroups divided by the signature showed different prognoses, expression levels of immune checkpoint genes, immune cell infiltration, and tumor microenvironment. The risk score was negatively correlated with the proportion of TIL, pDC, Mast cell, and T cell co-stimulation. The expression levels of genes in the signature were verified in PC and normal samples. The protein levels of SLC2A1, MMP14, TOP2A, MBOAT2, ANLN, and SLC22A3 showed up-regulation in PC samples compared with normal tissues. After integrating metabolomics and transcriptomics data, the alterations in OSPM in PC were investigated, and an OSPM-related signature was developed, which was helpful for the prognostic assessment and individualized treatment for PC.


Assuntos
Carcinoma , Neoplasias Pancreáticas , Humanos , Metaloproteinase 14 da Matriz , Multiômica , Neoplasias Pancreáticas/genética , Estresse Oxidativo/genética , Fosfolipídeos , Microambiente Tumoral/genética , Neoplasias Pancreáticas
20.
iScience ; 26(4): 106383, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37063464

RESUMO

Automatic identification system (AIS) is a vessel-based system for the automatic broadcast and reception of vessel information, and it also supports data for trajectory prediction. Since the vessel's sailing route is flexible and changeable and the AIS broadcast is unconfirmed, the trajectory varies greatly and the original AIS data contains some noisy trajectory, which leads to low prediction accuracy and stability. Therefore, to solve the above problem, this paper proposes a trajectory prediction method based on bidirectional gate recurrent unit (BiGRU) and trajectory direction vector (TDV) with attention mechanism. This paper firstly proposes a TDV to associate latitude and longitude with the course and speed. Then the paper proposes an attention mechanism to self-adaptively update weight to the TDV in different stages to eliminate unreasonable predicted trajectory points. Finally, this paper combines the TDV attention mechanism and the BiGRU network to train a vessel trajectory prediction model.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA