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1.
Circ Res ; 133(2): e19-e46, 2023 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-37313752

RESUMO

BACKGROUND: Systemic defects in intestinal iron absorption, circulation, and retention cause iron deficiency in 50% of patients with heart failure. Defective subcellular iron uptake mechanisms that are independent of systemic absorption are incompletely understood. The main intracellular route for iron uptake in cardiomyocytes is clathrin-mediated endocytosis. METHODS: We investigated subcellular iron uptake mechanisms in patient-derived and CRISPR/Cas-edited induced pluripotent stem cell-derived cardiomyocytes as well as patient-derived heart tissue. We used an integrated platform of DIA-MA (mass spectrometry data-independent acquisition)-based proteomics and signaling pathway interrogation. We employed a genetic induced pluripotent stem cell model of 2 inherited mutations (TnT [troponin T]-R141W and TPM1 [tropomyosin 1]-L185F) that lead to dilated cardiomyopathy (DCM), a frequent cause of heart failure, to study the underlying molecular dysfunctions of DCM mutations. RESULTS: We identified a druggable molecular pathomechanism of impaired subcellular iron deficiency that is independent of systemic iron metabolism. Clathrin-mediated endocytosis defects as well as impaired endosome distribution and cargo transfer were identified as a basis for subcellular iron deficiency in DCM-induced pluripotent stem cell-derived cardiomyocytes. The clathrin-mediated endocytosis defects were also confirmed in the hearts of patients with DCM with end-stage heart failure. Correction of the TPM1-L185F mutation in DCM patient-derived induced pluripotent stem cells, treatment with a peptide, Rho activator II, or iron supplementation rescued the molecular disease pathway and recovered contractility. Phenocopying the effects of the TPM1-L185F mutation into WT induced pluripotent stem cell-derived cardiomyocytes could be ameliorated by iron supplementation. CONCLUSIONS: Our findings suggest that impaired endocytosis and cargo transport resulting in subcellular iron deficiency could be a relevant pathomechanism for patients with DCM carrying inherited mutations. Insight into this molecular mechanism may contribute to the development of treatment strategies and risk management in heart failure.


Assuntos
Cardiomiopatia Dilatada , Insuficiência Cardíaca , Células-Tronco Pluripotentes Induzidas , Deficiências de Ferro , Humanos , Miócitos Cardíacos/metabolismo , Mutação , Cardiomiopatia Dilatada/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , Ferro/metabolismo , Clatrina/genética , Clatrina/metabolismo , Clatrina/farmacologia
2.
Antimicrob Agents Chemother ; 68(3): e0089323, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38259090

RESUMO

Staphylococcus aureus is an important human pathogen and vancomycin is widely used for the treatment of S. aureus infections. The global regulator agr is known as a well-described virulence regulator. Previous studies have found that agr-dysfunction strains are more likely to develop into vancomycin-resistant strains, but the mechanism for this phenomenon remains unknown. VraSR is a two-component regulatory system related to vancomycin resistance. In this study, we found that the expression levels of vraR were higher in agr-dysfunction clinical strains than in the agr-functional strains. We knocked out agr in a clinical strain, and quantitative reverse transcription PCR and ß-galactosidase activity assays revealed that agr repressed transcription of vraR. After vancomycin exposures, population analysis revealed larger subpopulations displaying reduced susceptibility in agr knockout strain compared with wild-type strain, and this pattern was also observed in agr-dysfunction clinical strains compared with the agr-functional strains. Electrophoretic mobility experiment demonstrated binding of purified AgrA to the promoter region of vraR. In conclusion, our results indicated that the loss of agr function in S. aureus may contribute to the evolution of reduced vancomycin susceptibility through the downregulation of vraSR.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Vancomicina/farmacologia , Antibacterianos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Regiões Promotoras Genéticas/genética , Proteínas de Bactérias/metabolismo
3.
Biochem Biophys Res Commun ; 695: 149401, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38154264

RESUMO

Human calcium sensing receptor (CaSR) senses calcium ion concentrations in vivo and is an important class of drug targets. Mutations in the receptor can lead to disorders of calcium homeostasis, including hypercalcemia and hypocalcemia. Here, 127 CaSR-targeted nanobodies were generated from camels, and four nanobodies with inhibitory function were further identified. Among these nanobodies, NB32 can effectively inhibit the mobilization of intracellular calcium ions (Ca2+i) and suppress the G12/13 and ERK1/2 signaling pathways downstream of CaSR. Moreover, it enhanced the inhibitory effect of the calcilytics as a negative allosteric modulator (NAM). We determined the structure of complex and found NB32 bound to LB2 (Ligand-binding 2) domain of CaSR to prevent the interaction of LB2 domains of two protomers to stabilize the inactive state of CaSR.


Assuntos
Hipercalcemia , Hipocalcemia , Anticorpos de Domínio Único , Humanos , Receptores de Detecção de Cálcio/metabolismo , Cálcio/metabolismo , Hipocalcemia/genética , Hipercalcemia/genética
4.
Brain ; 146(11): 4674-4689, 2023 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-37399508

RESUMO

Moyamoya disease is an uncommon cerebrovascular disorder characterized by steno-occlusive changes in the circle of Willis and abnormal vascular network development. Ring finger protein 213 (RNF213) has been identified as an important susceptibility gene for Asian patients, but researchers have not completely elucidated whether RNF213 mutations affect the pathogenesis of moyamoya disease. Using donor superficial temporal artery samples, whole-genome sequencing was performed to identify RNF213 mutation types in patients with moyamoya disease, and histopathology was performed to compare morphological differences between patients with moyamoya disease and intracranial aneurysm. The vascular phenotype of RNF213-deficient mice and zebrafish was explored in vivo, and RNF213 knockdown in human brain microvascular endothelial cells was employed to analyse cell proliferation, migration and tube formation abilities in vitro. After bioinformatics analysis of both cell and bulk RNA-seq data, potential signalling pathways were measured in RNF213-knockdown or RNF213-knockout endothelial cells. We found that patients with moyamoya disease carried pathogenic mutations of RNF213 that were positively associated with moyamoya disease histopathology. RNF213 deletion exacerbated pathological angiogenesis in the cortex and retina. Reduced RNF213 expression led to increased endothelial cell proliferation, migration and tube formation. Endothelial knockdown of RNF213 activated the Hippo pathway effector Yes-associated protein (YAP)/tafazzin (TAZ) and promoted the overexpression of the downstream effector VEGFR2. Additionally, inhibition of YAP/TAZ resulted in altered cellular VEGFR2 distribution due to defects in trafficking from the Golgi apparatus to the plasma membrane and reversed RNF213 knockdown-induced angiogenesis. All these key molecules were validated in ECs isolated from RNF213-deficient animals. Our findings may suggest that loss-of-function of RNF213 mediates the pathogenesis of moyamoya disease via the Hippo pathway.


Assuntos
Doença de Moyamoya , Humanos , Animais , Camundongos , Doença de Moyamoya/genética , Doença de Moyamoya/patologia , Células Endoteliais/metabolismo , Via de Sinalização Hippo , Peixe-Zebra/metabolismo , Neovascularização Patológica/genética , Predisposição Genética para Doença , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
5.
BMC Med Inform Decis Mak ; 24(1): 41, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38331788

RESUMO

In recent years, corneal refractive surgery has been widely used in clinics as an effective means to restore vision and improve the quality of life. When choosing myopia-refractive surgery, it is necessary to comprehensively consider the differences in equipment and technology as well as the specificity of individual patients, which heavily depend on the experience of ophthalmologists. In our study, we took advantage of machine learning to learn about the experience of ophthalmologists in decision-making and assist them in the choice of corneal refractive surgery in a new case. Our study was based on the clinical data of 7,081 patients who underwent corneal refractive surgery between 2000 and 2017 at the Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences. Due to the long data period, there were data losses and errors in this dataset. First, we cleaned the data and deleted the samples of key data loss. Then, patients were divided into three groups according to the type of surgery, after which we used SMOTE technology to eliminate imbalance between groups. Six statistical machine learning models, including NBM, RF, AdaBoost, XGBoost, BP neural network, and DBN were selected, and a ten-fold cross-validation and grid search were used to determine the optimal hyperparameters for better performance. When tested on the dataset, the multi-class RF model showed the best performance, with agreement with ophthalmologist decisions as high as 0.8775 and Macro F1 as high as 0.8019. Furthermore, the results of the feature importance analysis based on the SHAP technique were consistent with an ophthalmologist's practical experience. Our research will assist ophthalmologists in choosing appropriate types of refractive surgery and will have beneficial clinical effects.


Assuntos
Miopia , Procedimentos Cirúrgicos Refrativos , Humanos , Acuidade Visual , Qualidade de Vida , Miopia/cirurgia , Aprendizado de Máquina
6.
J Stroke Cerebrovasc Dis ; 33(3): 107581, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38224792

RESUMO

OBJECTIVE: Moyamoya disease (MMD) is a rare and progressive stenosis of cerebral arteries characterized by abnormally proliferative vasculopathy. Current studies have demonstrated that Neuregulin 1 (NRG1) plays a key role in angiogenesis-related disorders. Thus, the aim of our study is to investigate the serum NRG1 levels and their clinical correlations in MMD patients. METHODS: In this study, thirty adult patients with MMD and age-gender matched healthy controls were enrolled from our hospital between July 2020 and April 2022. Peripheral blood samples were collected at baseline, and clinical data were obtained from the electronic medical record system. Serum NRG1 concentrations were measured by enzyme-linked immunosorbent assay. Sanger sequencing was applied to detect the RNF213 p.R4810K mutation. RESULTS: The serum NRG1 levels were significantly higher in MMD patients compared to controls (14.48 ± 10.81 vs.7.54 ± 6.35mmol/L, p < 0.001). No statistical difference in baseline clinical characteristics was found between both groups. Correlation analyses showed that NRG1 levels were positively associated with Suzuki staging (r = 0.4137, p = 0.023) while not related to other clinical features (reduced cerebral blood flow, posterior cerebral artery involvement, bilateral or unilateral steno-occlusive changes). Furthermore, subgroup analysis revealed that MMD patients with the RNF213 p.R4810K mutation presented with significantly higher NRG1 levels than those without the mutation (9.60 ± 0.929 vs. 25.89 ± 4.338 mmol/L, p = 0.001). CONCLUSIONS: Our study suggests that increased serum NRG1 levels may constitute a characteristic feature of MMD, indicating a potential positive correlation with disease progression and the presence of the RNF213 mutation. This positions NRG1 as a potentially crucial target for further studies aimed at comprehending the pathogenesis of MMD.


Assuntos
Doença de Moyamoya , Adulto , Humanos , Adenosina Trifosfatases/genética , Biomarcadores , Estudos de Casos e Controles , China , Progressão da Doença , Predisposição Genética para Doença , Doença de Moyamoya/diagnóstico , Doença de Moyamoya/genética , Neuregulina-1/genética , Ubiquitina-Proteína Ligases/genética
7.
J Struct Biol ; 215(3): 107996, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37419228

RESUMO

The evolving SARS-CoV-2 Omicron strain has repeatedly caused widespread disease epidemics, and effective antibody drugs continue to be in short supply. Here, we identified a batch of nanobodies with high affinity for receptor binding domain (RBD) of SARS-CoV-2 spike protein, separated them into three classes using high performance liquid chromatography (HPLC), and then resolved the crystal structure of the ternary complexes of two non-competing nanobodies (NB1C6 and NB1B5) with RBD using X-ray crystallography. The structures showed that NB1B5 and NB1C6 bind to the left and right flank of the RBD, respectively, and that the binding epitopes are highly conserved cryptic sites in all SARS-CoV-2 mutant strains, as well as that NB1B5 can effectively block the ACE2. These two nanobodies were covalently linked into multivalent and bi-paratopic formats, and have a high affinity and neutralization potency for omicron, potentially inhibiting viral escape. The binding sites of these two nanobodies are relatively conserved, which help guide the structural design of antibodies targeting future variants of SARS-CoV-2 to combat COVID-19 epidemics and pandemics.


Assuntos
COVID-19 , Anticorpos de Domínio Único , Humanos , SARS-CoV-2/genética , Anticorpos , Epitopos/genética , Anticorpos Neutralizantes
8.
Chemistry ; 29(24): e202204031, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-36745151

RESUMO

Photocatalytic methane oxidation to oxygenates with promising performance remains as a grand challenge due to the low productivity and severe overoxidation. Herein, SrWO4 /TiO2 heterojunction was developed for photocatalytic methane oxidation with O2 to liquid oxygenates ( Please replace "oxygenates" with "oxygenated")products under mild reaction conditions. The optimized SrWO4 /TiO2 catalyst exhibited high productivity of 13365 µmol/g with high selectivity of 98.7 % for oxygenates. Benefited from the intimate heterojunction interface of SrWO4 /TiO2 , the constructed I-type heterostructure improved the separation and transfer of photogenerated carriers, and a high-speed transfer channel for photogenerated carriers was fabricated. Simultaneously, the special band structure can increase the amount of photogenerated electrons and holes on the TiO2 surface, which promoted the formation of reactive oxygen species to enhance liquid oxygenates productivity.

9.
Protein Expr Purif ; 207: 106267, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37030644

RESUMO

Coronavirus Papain-like protease (PLpro) mediates the cleavage of viral polyproteins and assists the virus escaping from innate immune response. Thus, PLpro is an attractive target for the development of broad-spectrum drugs as it has a conserved structure across different coronaviruses. In this study, we purified SARS-CoV-2 PLpro as an immune antigen, constructed a nanobody phage display library, and identified a set of nanobodies with high affinity for SARS-CoV-2. In addition, enzyme activity experiments demonstrated that two nanobodies had a significant inhibitory effect on the PLpro. These nanobodies should therefore be investigated as candidates for the treatment of coronaviruses.


Assuntos
COVID-19 , Anticorpos de Domínio Único , Humanos , Proteases Semelhantes à Papaína de Coronavírus , SARS-CoV-2 , Peptídeo Hidrolases , Papaína/química
10.
Protein Expr Purif ; 207: 106268, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37023993

RESUMO

As one of the receptors of the TAM family, AXL plays a vital role in stem cell maintenance, angiogenesis, immune escape of viruses and drug resistance against tumors. In this study, the truncated extracellular segment containing two immunoglobulin-like domains of human AXL (AXL-IG), which has been confirmed to bind growth arrest specific 6 (GAS6) by structural studies [1], was expressed in a prokaryotic expression system and then purified. Immunizing camelid with the purified AXL-IG as antigen could lead to the production of unique nanobodies composed of only variable domain of heavy chain of heavy-chain antibody (VHH), which are around 15 kD and stable. We screened out a nanobody A-LY01 specific binding to AXL-IG. We further determined the affinity of A-LY01 to AXL-IG and revealed that A-LY01 could specifically recognize full-length AXL on the surface of HEK 293T/17 cells. Our study provides appropriate support for the development of diagnostic reagents and antibody therapeutics targeting AXL.


Assuntos
Escherichia coli , Neoplasias , Humanos , Escherichia coli/genética , Anticorpos , Cadeias Pesadas de Imunoglobulinas
11.
Ther Drug Monit ; 45(5): 660-667, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37185798

RESUMO

BACKGROUND: This study aimed to assess the effect of perampanel dose, age, sex, and antiseizure medication cotherapy on steady-state free-perampanel concentration in children with refractory epilepsy, as well as the relationship between inflammation and the pharmacokinetics of perampanel. METHODS: This prospective study in China included 87 children with refractory epilepsy treated with adjunctive perampanel therapy. Free and total perampanel concentrations in plasma were determined using liquid chromatography-tandem mass spectrometry. Free-perampanel concentration was compared among patients with various potential influencing factors. RESULTS: A total of 87 pediatric patients (44 female children) aged 2-14 years were enrolled. The mean free-perampanel concentration and free concentration-to-dose (CD) ratio in plasma were 5.7 ± 2.7 ng/mL (16.3 ± 7.7 nmol/L) and 45.3 ± 21.0 (ng/mL)/(mg/kg) [129.6 ± 60.1 (nmol/L)/(mg/kg)], respectively. The protein binding of perampanel in plasma was 97.98%. A linear relationship was observed between perampanel dose and free concentration in plasma, and a positive relationship was found between the total and free-perampanel concentrations. Concomitant use of oxcarbazepine reduced the free CD ratio by 37%. Concomitant use of valproic acid increased the free CD ratio by 52%. Five patients had a plasma high-sensitivity C-reactive protein (Hs-CRP) level of >5.0 mg/L (Hs-CRP positive). The total and free CD ratios of perampanel were increased in patients with inflammation. Two patients with inflammation developed adverse events, which disappeared as the Hs-CRP level returned to normal, and neither required perampanel dose reduction. Age and sex did not influence the free-perampanel concentration. CONCLUSIONS: This study found complex drug interactions between perampanel and other concomitant antiseizure medications, providing valuable information to enable clinicians to apply perampanel in the future reasonably. In addition, it may be important to quantify both the total and free concentrations of perampanel to assess complex pharmacokinetic interactions.


Assuntos
Anticonvulsivantes , Epilepsia Resistente a Medicamentos , Humanos , Criança , Feminino , Anticonvulsivantes/farmacocinética , Epilepsia Resistente a Medicamentos/tratamento farmacológico , Proteína C-Reativa , Monitoramento de Medicamentos/métodos , Estudos Prospectivos , Quimioterapia Combinada , Relação Dose-Resposta a Droga , Piridonas/farmacocinética , Inflamação/tratamento farmacológico , Resultado do Tratamento
12.
Antimicrob Agents Chemother ; 66(7): e0007322, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35758720

RESUMO

Metronidazole (Met) is the first choice for treating Helicobacter pylori (Hp). However, Hp is easy to resistant, making Met unable to be widely used. How to overcome Hp's Met resistance is still an issue. In this study, Met was used as the primary raw material with linolenic acid to prepare a novel compound-linolenic acid-metronidazole (Lla-Met). The MIC, minimum bactericidal concentration (MBC), colonization amount of Hp in gastric mucosa, etc., were evaluated, respectively. Lla-Met was successfully prepared by the detection of nuclear magnetic resonance, etc., and its MIC and MBC to Hp were 2~4 µg/mL, 8~16 µg/mL. Moreover, in vivo experiments, Lla-Met significantly reduced the colonization of drug-resistant Hp in gastric mucosa. In the toxicity test, Lla-Met inhibited rate to GES-1 and BGC823 cells were 15% at 128 µg/mL; the mice were administered 10 times treatment Lla-Met treatment (240 mg/kg), have no difference significant injuries were found in their stomach, liver, spleen, kidney, and weight. In addition, Hp G27 continued for 18 days in vitro with sub-Lla-Met concentration, G27 did not show drug resistance to Lla-Met; Lla-Met did not exert an effect on non-Hp species with 128 µg/mL; Compared with a neutral environment, when the acid concentration is 3.0, Lla-Met is not decomposed and has better stability. Conclusion: Lla-Met, a newly prepared compound, has relatively well antibacterial of Met-resistant and sensitive Hp, with a capability of overcoming the metronidazole resistance of Hp.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Claritromicina/farmacologia , Resistência a Medicamentos , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/microbiologia , Metronidazol/farmacologia , Metronidazol/uso terapêutico , Camundongos , Ácido alfa-Linolênico/farmacologia
13.
Environ Sci Technol ; 56(16): 11409-11417, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35905382

RESUMO

Hydrology is a key factor influencing microbial degradation of emerging organic contaminants (EOCs) in soils, but the underlying mechanisms are not clear. In this study, biotic and abiotic column experiments were performed to investigate the removal and degradation of five EOCs in soils with different soil organic matter (SOM) contents under saturated and unsaturated flow conditions. In biotic experiments, 54-90% of bisphenol A (BPA) and 9-22% of ibuprofen (IBU) were removed from the aqueous phase of saturated columns due to adsorption and biodegradation. The biodegradation removed 26-65% of BPA and 1-22% of IBU. Decreasing soil pore water saturation from 100 to 80% increased BPA removal to 97-100% and IBU removal to 42-43% due to increased biodegradation (67-81% for BPA and 36-39% for IBU). No significant removal of BPA and IBU was observed in SOM-removed soils under saturated and unsaturated flow conditions. The desaturation did not influence sorptive losses of BPA (<27%) and IBU (<7%), suggesting their negligible adsorption at air-water interfaces but increased biodegradation of BPA and IBU sorbed at SOM-water interfaces. The study shows that soil drying and SOM can synergistically degrade BPA and IBU but have no effect on recalcitrant carbamazepine, tetracycline, and ciprofloxacin.


Assuntos
Poluentes do Solo , Solo , Adsorção , Biodegradação Ambiental , Poluentes do Solo/análise , Água
14.
Nature ; 538(7623): 84-87, 2016 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-27708303

RESUMO

Lower olefins-generally referring to ethylene, propylene and butylene-are basic carbon-based building blocks that are widely used in the chemical industry, and are traditionally produced through thermal or catalytic cracking of a range of hydrocarbon feedstocks, such as naphtha, gas oil, condensates and light alkanes. With the rapid depletion of the limited petroleum reserves that serve as the source of these hydrocarbons, there is an urgent need for processes that can produce lower olefins from alternative feedstocks. The 'Fischer-Tropsch to olefins' (FTO) process has long offered a way of producing lower olefins directly from syngas-a mixture of hydrogen and carbon monoxide that is readily derived from coal, biomass and natural gas. But the hydrocarbons obtained with the FTO process typically follow the so-called Anderson-Schulz-Flory distribution, which is characterized by a maximum C2-C4 hydrocarbon fraction of about 56.7 per cent and an undesired methane fraction of about 29.2 per cent (refs 1, 10, 11, 12). Here we show that, under mild reaction conditions, cobalt carbide quadrangular nanoprisms catalyse the FTO conversion of syngas with high selectivity for the production of lower olefins (constituting around 60.8 per cent of the carbon products), while generating little methane (about 5.0 per cent), with the ratio of desired unsaturated hydrocarbons to less valuable saturated hydrocarbons amongst the C2-C4 products being as high as 30. Detailed catalyst characterization during the initial reaction stage and theoretical calculations indicate that preferentially exposed {101} and {020} facets play a pivotal role during syngas conversion, in that they favour olefin production and inhibit methane formation, and thereby render cobalt carbide nanoprisms a promising new catalyst system for directly converting syngas into lower olefins.


Assuntos
Alcenos/síntese química , Monóxido de Carbono/química , Carbono/química , Carvão Mineral , Cobalto/química , Hidrogênio/química , Nanoestruturas/química , Gás Natural , Biomassa , Catálise , Metano/síntese química , Microscopia Eletrônica de Transmissão , Nanoestruturas/ultraestrutura , Pressão
15.
Circ Res ; 125(1): 90-103, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31104567

RESUMO

RATIONALE: The immature presentation of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) is currently a challenge for their application in disease modeling, drug screening, and regenerative medicine. Long-term culture is known to achieve partial maturation of iPSC-CMs. However, little is known about the molecular signaling circuitries that govern functional changes, metabolic output, and cellular homeostasis during long-term culture of iPSC-CMs. OBJECTIVE: We aimed to identify and characterize critical signaling events that control functional and metabolic transitions of cardiac cells during developmental progression, as recapitulated by long-term culture of iPSC-CMs. METHODS AND RESULTS: We combined transcriptomic sequencing with pathway network mapping in iPSC-CMs that were cultured until a late time point, day 200, in comparison to a medium time point, day 90, and an early time point, day 30. Transcriptomic landscapes of long-term cultured iPSC-CMs allowed mapping of distinct metabolic stages during development of maturing iPSC-CMs. Temporally divergent control of mitochondrial metabolism was found to be regulated by cAMP/PKA (protein kinase A)- and proteasome-dependent signaling events. The PKA/proteasome-dependent signaling cascade was mediated downstream by Hsp90 (heat shock protein 90), which in turn modulated mitochondrial respiratory chain proteins and their metabolic output. During long-term culture, this circuitry was found to initiate upregulation of iPSC-CM metabolism, resulting in increased cell contractility that reached a maximum at the day 200 time point. CONCLUSIONS: Our results reveal a PKA/proteasome- and Hsp90-dependent signaling pathway that regulates mitochondrial respiratory chain proteins and determines cardiomyocyte energy production and functional output. These findings provide deeper insight into signaling circuitries governing metabolic homeostasis in iPSC-CMs during developmental progression.


Assuntos
Metabolismo Energético/fisiologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Diferenciação Celular/fisiologia , Células Cultivadas , Humanos , Potencial da Membrana Mitocondrial/fisiologia , Camundongos
16.
Mikrochim Acta ; 188(11): 405, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34731318

RESUMO

With polyacrylonitrile nanofibers mat (PAN NFsM) as a template, molecularly imprinted resin/polydopamine nanofibers mat (MIR/PDA NFsM) was synthesized for the extraction of sulfonamides (SAs) in water. The specific surface area and pore volume were increased obviously due to the functionalization of MIR. The adsorption efficiencies of MIR/PDA NFsM under optimized conditions for SAs were 92.3-99.3%. Possible adsorption mechanisms of imprinting recognition and hydrogen bond interactions were also put forward. Compared with MIR particles, the MIR/PDA NFsM exhibited much superior adsorption performance. Particularly, the outstanding mass transfer efficiency of MIR/PDA NFsM was much higher than the other reported adsorbents for SAs. Finally, a new method based on the solid-phase extraction (SPE) of MIR/PDA NFsM was successfully developed for the detection of five SAs in environmental water with HPLC-MS/MS and applied to the analysis of actual samples. Under the selected conditions, the enrichment factors of MIR/PDA NFsM of SCP, SMT, SMZ, SMR, and SMX were between 23.0 and 25.0. Low detection limits (0.26-0.76 ng L-1), broad linear range (1.0 ng L-1 to 10.0 µg L-1), and satisfactory recoveries (82.8-115.6%) and precisions (RSDs < 7.2%) were obtained. Moreover, the excellent reusability properties and storage stability endowed MIR/PDA NFsM with great value for practical applications.


Assuntos
Indóis/química , Polímeros Molecularmente Impressos/química , Nanofibras/química , Polímeros/química , Sulfonamidas/análise , Poluentes Químicos da Água/análise , Resinas Acrílicas/química , Adsorção , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Extração em Fase Sólida , Sulfonamidas/química , Sulfonamidas/isolamento & purificação , Espectrometria de Massas em Tandem , Águas Residuárias/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
17.
Bull Environ Contam Toxicol ; 107(4): 700-709, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33515266

RESUMO

Inland waters are the main medium transporting microplastics to the ocean. Aggregation, vertical settlement, and horizontal transport will occur when microplastics enter the inland waterbodies. This paper reviews these behaviors of microplastics in inland waters and their influencing factors. The aggregation of microplastics were divided into homogeneous aggregation and heterogeneous aggregation, which are critical for the settlement of microplastics. The settlement of microplastics in inland water bodies is influenced by microplastic properties (size, density, and shapes) and environmental conditions (microorganisms, sedimental properties, hydraulic conditions, and so on). Horizontal transport of microplastics in water is influenced by hydrologic conditions, rainfall, river morphologies, dams, vegetation, etc. Future perspectives including laboratory simulations and numerical models involving multiple factors, the behaviors of degradable plastics, and the influence of hydrologic conditions have been proposed.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Plásticos , Rios , Poluentes Químicos da Água/análise
18.
Anal Chem ; 92(20): 13930-13935, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32969220

RESUMO

The quantitative detection methods for many microplastic (MP) polymers in the environment are inadequate. For example, effective detection methods for nylon (polyamide, PA), a widely used plastic, in different environmental samples are still lacking. In the present study, a method based on acid depolymerization-liquid chromatography-tandem mass spectrometry (LC-MS/MS) and without the separation of MPs from samples was developed to quantify nylon MPs. After removing the background monomer compounds, PA6 and PA66 were efficiently depolymerized to 6-aminocaproic acid and adipic acid, respectively, and detected by LC-MS/MS. Accordingly, the quantity of nylon MPs was accurately calculated. By using the proposed method, the recovery of spiked PA6 and PA66 MPs in the environmental samples ranged from 90.8 to 98.8%. The limits of quantification for PA6 and PA66 MPs were 0.680 and 4.62 mg/kg, respectively. PA MPs were widely detected in indoor dust, sludge, marine sediment, freshwater sediment, fishery sediment, and fish guts and gills with concentrations of 0.725-321 mg/kg. Extremely high concentrations of PA66 MPs were detected in indoor dust and fish guts and gills, indicating the unequivocal risk of human exposure through dust ingestion and dietary exposure.


Assuntos
Microplásticos/análise , Nylons/química , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção
19.
Biol Chem ; 402(1): 113-121, 2020 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-33544492

RESUMO

We developed a new approach for combined analysis of calcium (Ca2+) handling and beating forces in contractile cardiomyocytes. We employed human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from dilated cardiomyopathy (DCM) patients carrying an inherited mutation in the sarcomeric protein troponin T (TnT), and isogenic TnT-KO iPSC-CMs generated via CRISPR/Cas9 gene editing. In these cells, Ca2+ handling as well as beating forces and -rates using single-cell atomic force microscopy (AFM) were assessed. We report impaired Ca2+ handling and reduced contractile force in DCM iPSC-CMs compared to healthy WT controls. TnT-KO iPSC-CMs display no contractile force or Ca2+ transients but generate Ca2+ sparks. We apply our analysis strategy to Ca2+ traces and AFM deflection recordings to reveal maximum rising rate, decay time, and duration of contraction with a multi-step background correction. Our method provides adaptive computing of signal peaks for different Ca2+ flux or force levels in iPSC-CMs, as well as analysis of Ca2+ sparks. Moreover, we report long-term measurements of contractile force dynamics on human iPSC-CMs. This approach enables deeper and more accurate profiling of disease-specific differences in cardiomyocyte contraction profiles using patient-derived iPSC-CMs.


Assuntos
Cálcio/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Cálcio/análise , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Microscopia de Força Atômica , Miócitos Cardíacos/patologia
20.
BMC Gastroenterol ; 20(1): 340, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059618

RESUMO

BACKGROUND: Previous studied revealed that psoriasis and Inflammatory bowel disease (IBD) have highly overlapping epidemiological characteristics, genetic susceptibility loci, disease risk factors, immune mechanisms, and comorbidities. More and more biologics have been used to treat psoriasis and IBD. Interleukin (IL)-17 inhibitors played an important role in the treatment of psoriasis, but induced and aggravated inflammatory bowel disease in some patients. IL-23 inhibitors have shown to be effective to both psoriasis and CD. CASE PRESENTATION: Forty-one year old Chinese male patient who came to the hospital for psoriasis, developed severe gastrointestinal symptoms after using an IL-17 inhibitor, and was diagnosed with Crohn's disease (CD). The patient eventually used an IL-23 inhibitor to relieve both psoriasis and CD. CONCLUSION: IBD patients and psoriasis patients have increased probability of suffering from the other disease. The case that patients had suffered from psoriasis and CD before the use of IL-17 inhibitor is quite rare. This case suggests that physicians need to be careful when treating patients with psoriasis and CD with biologics, and it is necessary to evaluate the gastrointestinal tract.


Assuntos
Doença de Crohn , Interleucina-17/antagonistas & inibidores , Psoríase , Adulto , Doença de Crohn/induzido quimicamente , Humanos , Masculino , Psoríase/tratamento farmacológico
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