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1.
Cell ; 2024 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-39413786

RESUMO

Cardiac fibrosis impairs cardiac function, but no effective clinical therapies exist. To address this unmet need, we employed a high-throughput screening for antifibrotic compounds using human induced pluripotent stem cell (iPSC)-derived cardiac fibroblasts (CFs). Counter-screening of the initial candidates using iPSC-derived cardiomyocytes and iPSC-derived endothelial cells excluded hits with cardiotoxicity. This screening process identified artesunate as the lead compound. Following profibrotic stimuli, artesunate inhibited proliferation, migration, and contraction in human primary CFs, reduced collagen deposition, and improved contractile function in 3D-engineered heart tissues. Artesunate also attenuated cardiac fibrosis and improved cardiac function in heart failure mouse models. Mechanistically, artesunate targeted myeloid differentiation factor 2 (MD2) and inhibited MD2/Toll-like receptor 4 (TLR4) signaling pathway, alleviating fibrotic gene expression in CFs. Our study leverages multiscale drug screening that integrates a human iPSC platform, tissue engineering, animal models, in silico simulations, and multiomics to identify MD2 as a therapeutic target for cardiac fibrosis.

2.
Cell ; 179(5): 1160-1176.e24, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31730855

RESUMO

Pediatric-onset colitis and inflammatory bowel disease (IBD) have significant effects on the growth of infants and children, but the etiopathogenesis underlying disease subtypes remains incompletely understood. Here, we report single-cell clustering, immune phenotyping, and risk gene analysis for children with undifferentiated colitis, Crohn's disease, and ulcerative colitis. We demonstrate disease-specific characteristics, as well as common pathogenesis marked by impaired cyclic AMP (cAMP)-response signaling. Specifically, infiltration of PDE4B- and TNF-expressing macrophages, decreased abundance of CD39-expressing intraepithelial T cells, and platelet aggregation and release of 5-hydroxytryptamine at the colonic mucosae were common in colitis and IBD patients. Targeting these pathways by using the phosphodiesterase inhibitor dipyridamole restored immune homeostasis and improved colitis symptoms in a pilot study. In summary, comprehensive analysis of the colonic mucosae has uncovered common pathogenesis and therapeutic targets for children with colitis and IBD.


Assuntos
Doenças Inflamatórias Intestinais/patologia , Doenças Inflamatórias Intestinais/terapia , Mucosa Intestinal/patologia , Antígenos CD/metabolismo , Apirase/metabolismo , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Morte Celular/efeitos dos fármacos , Microambiente Celular/efeitos dos fármacos , Criança , Estudos de Coortes , Colo/patologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Dipiridamol/farmacologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Predisposição Genética para Doença , Homeostase/efeitos dos fármacos , Humanos , Imunoglobulina G/sangue , Memória Imunológica , Inflamação/patologia , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/genética , Interferon Tipo I/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Metilprednisolona/farmacologia , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismo
3.
Proc Natl Acad Sci U S A ; 121(39): e2318900121, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39288178

RESUMO

Small-conductance Ca2+-activated K+ channels (SK, KCa2) are gated solely by intracellular microdomain Ca2+. The channel has emerged as a therapeutic target for cardiac arrhythmias. Calmodulin (CaM) interacts with the CaM binding domain (CaMBD) of the SK channels, serving as the obligatory Ca2+ sensor to gate the channels. In heterologous expression systems, phosphatidylinositol 4,5-bisphosphate (PIP2) coordinates with CaM in regulating SK channels. However, the roles and mechanisms of PIP2 in regulating SK channels in cardiomyocytes remain unknown. Here, optogenetics, magnetic nanoparticles, combined with Rosetta structural modeling, and molecular dynamics (MD) simulations revealed the atomistic mechanisms of how PIP2 works in concert with Ca2+-CaM in the SK channel activation. Our computational study affords evidence for the critical role of the amino acid residue R395 in the S6 transmembrane segment, which is localized in propinquity to the intracellular hydrophobic gate. This residue forms a salt bridge with residue E398 in the S6 transmembrane segment from the adjacent subunit. Both R395 and E398 are conserved in all known isoforms of SK channels. Our findings suggest that the binding of PIP2 to R395 residue disrupts the R395:E398 salt bridge, increasing the flexibility of the transmembrane segment S6 and the activation of the channel. Importantly, our findings serve as a platform for testing of structural-based drug designs for therapeutic inhibitors and activators of the SK channel family. The study is timely since inhibitors of SK channels are currently in clinical trials to treat atrial arrhythmias.


Assuntos
Calmodulina , Simulação de Dinâmica Molecular , Fosfatidilinositol 4,5-Difosfato , Canais de Potássio Ativados por Cálcio de Condutância Baixa , Fosfatidilinositol 4,5-Difosfato/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Baixa/química , Canais de Potássio Ativados por Cálcio de Condutância Baixa/genética , Animais , Calmodulina/metabolismo , Calmodulina/química , Humanos , Ativação do Canal Iônico , Cálcio/metabolismo , Ligação Proteica , Miócitos Cardíacos/metabolismo
4.
Proc Natl Acad Sci U S A ; 120(6): e2216230120, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-36724251

RESUMO

Gastrin releasing peptide receptor (GRPR), a member of the bombesin (BBN) G protein-coupled receptors, is aberrantly overexpressed in several malignant tumors, including those of the breast, prostate, pancreas, lung, and central nervous system. Additionally, it also mediates non-histaminergic itch and pathological itch conditions in mice. Thus, GRPR could be an attractive target for cancer and itch therapy. Here, we report the inactive state crystal structure of human GRPR in complex with the non-peptide antagonist PD176252, as well as two active state cryo-electron microscopy (cryo-EM) structures of GRPR bound to the endogenous peptide agonist gastrin-releasing peptide and the synthetic BBN analog [D-Phe6, ß-Ala11, Phe13, Nle14] Bn (6-14), in complex with Gq heterotrimers. These structures revealed the molecular mechanisms for the ligand binding, receptor activation, and Gq proteins signaling of GRPR, which are expected to accelerate the structure-based design of GRPR antagonists and agonists for the treatments of cancer and pruritus.


Assuntos
Neoplasias , Receptores da Bombesina , Masculino , Humanos , Camundongos , Animais , Receptores da Bombesina/agonistas , Receptores da Bombesina/metabolismo , Microscopia Crioeletrônica , Bombesina/farmacologia , Peptídeo Liberador de Gastrina/metabolismo , Prurido/metabolismo
5.
Exp Cell Res ; 439(1): 114096, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38768700

RESUMO

Early vascularization plays an essential role during the whole process in bone regeneration because of the function of secreting cytokines, transporting nutrients and metabolic wastes. As the preliminary basis of bone repair, angiogenesis is regulated by immune cells represented by macrophages to a great extent. However, with the discovery of the endolymphatic circulation system inside bone tissue, the role of vascularization became complicated and confusing. Herein, we developed a macrophage/lymphatic endothelial cells (LECs)/human umbilical vein endothelial cells (HUVECs) co-culture system to evaluate the effect of macrophage treated lymphatic endothelial cells on angiogenesis in vitro and in vivo. In this study, we collected the medium from macrophage (CM) for LECs culture. We found that CM2 could promote the expression of LECs markers and migration ability, which indicated the enhanced lymphogenesis. In addition, the medium from LECs was collected for culturing HUVECs. The CM2-treated LECs showed superior angiogenesis property including the migration capacity and expression of angiogenetic markers, which suggested the superior vascularization. Rat femoral condyle defect model was applied to confirm the hypothesis in vivo. Generally, M2-macrophage treated LECs showed prominent angiogenetic potential coupling with osteogenesis.


Assuntos
Técnicas de Cocultura , Células Endoteliais da Veia Umbilical Humana , Macrófagos , Neovascularização Fisiológica , Osteogênese , Humanos , Animais , Células Endoteliais da Veia Umbilical Humana/metabolismo , Macrófagos/metabolismo , Ratos , Células Endoteliais/metabolismo , Movimento Celular , Ratos Sprague-Dawley , Regeneração Óssea/fisiologia , Camundongos , Células Cultivadas , Masculino , Angiogênese
6.
Proc Natl Acad Sci U S A ; 119(36): e2206708119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36044551

RESUMO

The sinoatrial node (SAN), the leading pacemaker region, generates electrical impulses that propagate throughout the heart. SAN dysfunction with bradyarrhythmia is well documented in heart failure (HF). However, the underlying mechanisms are not completely understood. Mitochondria are critical to cellular processes that determine the life or death of the cell. The release of Ca2+ from the ryanodine receptors 2 (RyR2) on the sarcoplasmic reticulum (SR) at mitochondria-SR microdomains serves as the critical communication to match energy production to meet metabolic demands. Therefore, we tested the hypothesis that alterations in the mitochondria-SR connectomics contribute to SAN dysfunction in HF. We took advantage of a mouse model of chronic pressure overload-induced HF by transverse aortic constriction (TAC) and a SAN-specific CRISPR-Cas9-mediated knockdown of mitofusin-2 (Mfn2), the mitochondria-SR tethering GTPase protein. TAC mice exhibited impaired cardiac function with HF, cardiac fibrosis, and profound SAN dysfunction. Ultrastructural imaging using electron microscope (EM) tomography revealed abnormal mitochondrial structure with increased mitochondria-SR distance. The expression of Mfn2 was significantly down-regulated and showed reduced colocalization with RyR2 in HF SAN cells. Indeed, SAN-specific Mfn2 knockdown led to alterations in the mitochondria-SR microdomains and SAN dysfunction. Finally, disruptions in the mitochondria-SR microdomains resulted in abnormal mitochondrial Ca2+ handling, alterations in localized protein kinase A (PKA) activity, and impaired mitochondrial function in HF SAN cells. The current study provides insights into the role of mitochondria-SR microdomains in SAN automaticity and possible therapeutic targets for SAN dysfunction in HF patients.


Assuntos
Conectoma , Insuficiência Cardíaca , Mitocôndrias Cardíacas , Retículo Sarcoplasmático , Síndrome do Nó Sinusal , Nó Sinoatrial , Animais , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Camundongos , Mitocôndrias Cardíacas/ultraestrutura , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Retículo Sarcoplasmático/patologia , Síndrome do Nó Sinusal/patologia , Síndrome do Nó Sinusal/fisiopatologia , Nó Sinoatrial/fisiopatologia
7.
Plant Physiol ; 191(1): 660-678, 2023 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-36269175

RESUMO

Herbivore-associated molecular patterns (HAMPs) enable plants to recognize herbivores and may help plants adjust their defense responses. Here, we report on herbivore-induced changes in a protein disulfide isomerase (PDI) widely distributed across arthropods. PDI from the spider mite Tetranychus evansi (TePDI), a mesophyll-feeding agricultural pest worldwide, triggered immunity in multiple Solanaceae plants. TePDI-mediated cell death in Nicotiana benthamiana required the plant signaling proteins SGT1 (suppressor of the G2 allele of skp1) and HSP90 (heat shock protein 90), but was suppressed by spider mite effectors Te28 and Te84. Moreover, PDIs from phylogenetically distinct herbivorous and nonherbivorous arthropods triggered plant immunity. Finally, although PDI-induced plant defenses impaired the performance of spider mites on plants, RNAi experiments revealed that PDI genes are essential for the survival of mites and whiteflies. Our findings indicate that plants recognize evolutionarily conserved HAMPs to activate plant defense and resist pest damage, pointing to opportunities for broad-spectrum pest management.


Assuntos
Herbivoria , Tetranychidae , Animais , Isomerases de Dissulfetos de Proteínas/genética , Plantas , Nicotiana/genética , Proteínas de Plantas/genética , Tetranychidae/fisiologia
8.
J Exp Bot ; 75(5): 1493-1509, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-37952109

RESUMO

Herbivore-associated elicitors (HAEs) are active molecules produced by herbivorous insects. Recognition of HAEs by plants induces defence that resist herbivore attacks. We previously demonstrated that the tomato red spider mite Tetranychus evansi triggered defence in Nicotiana benthamiana. However, our knowledge of HAEs from T. evansi remains limited. Here, we characterize a novel HAE, Te16, from T. evansi and dissect its function in mite-plant interactions. We investigate the effects of Te16 on spider mites and plants by heterologous expression, virus-induced gene silencing assay, and RNA interference. Te16 induces cell death, reactive oxygen species (ROS) accumulation, callose deposition, and jasmonate (JA)-related responses in N. benthamiana leaves. Te16-mediated cell death requires a calcium signalling pathway, cytoplasmic localization, the plant co-receptor BAK1, and the signalling components SGT1 and HSP90. The active region of Te16-induced cell death is located at amino acids 114-293. Moreover, silencing Te16 gene in T. evansi reduces spider mite survival and hatchability, but expressing Te16 in N. benthamiana leaves enhances plant resistance to herbivores. Finally, Te16 gene is specific to Tetranychidae species and is highly conserved in activating plant immunity. Our findings reveal a novel salivary protein produced by spider mites that elicits plant defence and resistance to insects, providing valuable clues for pest management.


Assuntos
Solanum lycopersicum , Tetranychidae , Animais , Herbivoria , Tetranychidae/fisiologia , Nicotiana/genética , Solanum lycopersicum/genética , Folhas de Planta
9.
Eur J Clin Invest ; 54(5): e14156, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38214411

RESUMO

BACKGROUND: Patients with ischemic heart disease (IHD) experience a high incidence of progression to heart failure (HF) despite current therapies. We speculated that steroid hormone metabolic disorders distinct adverse phenotypes and contribute to HF. METHODS: We measured 18 steroids using liquid chromatography with tandem mass spectrometry in 2023 patients from the Registry Study of Biomarkers in Ischemic Heart Disease (BIOMS-IHD), including 1091 patients with IHD in a retrospective discovery set and 932 patients with IHD in a multicentre validation set. Our outcomes included incident HF after a median follow-up of 4 years. RESULTS: We demonstrated steroid-based signatures of inflammation, coronary microvascular dysfunction and left ventricular hypertrophy that were associated with subsequent HF events in patients with IHD. In both cohorts, patients with a high steroid-heart failure score (SHFS) (>1) exhibited a greater risk of incident HF than patients with a low SHFS (≤1). The SHFS further improved the prognostic accuracy beyond clinical variables (net reclassification improvement of 0.628 in the discovery set and 0.299 in the validation set) and demonstrated the maximal effect of steroid signatures in patients with IHD who had lower B-type natriuretic peptide levels (pinteraction = 0.038). CONCLUSIONS: A steroid-based strategy can simply and effectively identify individuals at higher HF risk who may derive benefit from more intensive follow-ups.


Assuntos
Insuficiência Cardíaca , Isquemia Miocárdica , Humanos , Estudos Retrospectivos , Fatores de Risco , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/complicações , Isquemia Miocárdica/epidemiologia , Isquemia Miocárdica/complicações , Biomarcadores , Esteroides
10.
BMC Gastroenterol ; 24(1): 341, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39354355

RESUMO

BACKGROUND: Colonoscopic enteral tube placement using current methods has some shortcomings, such as the complexity of the procedure and tube dislodgement. The magnetic navigation technique (MNT) has been proven effective for nasoenteral feeding tube placement, and is associated with reduced cost and time to initiation of nutrition. This study attempted to develop a novel method for enteral tube placement using MNT. METHODS: The MNT device consisted of an external magnet and a 12 Fr tube with a magnet at the end. Ten swine were used, and bowel cleansing was routinely performed before colonoscopy. Intravenous anesthesia with propofol and ketamine was administered. A colonoscopic enteral tube was placed using the MNT. The position of the end of the enteral tube was determined by radiography, and angiography was performed to check for colonic perforations. Colonoscopy was used to detect intestinal mucosal damage after tube removal. RESULTS: MNT-assisted colonoscopic enteral tube placement was successfully completed in all pigs. The median operating time was 30 (26-47) min. No colon perforation was detected on colonography after enteral tube placement, and no colonic mucosal bleeding or injury was detected after the removal of the enteral tube. CONCLUSIONS: MNT-assisted colonoscopic enteral tube placement is feasible and safe in swine and may represent a valuable method for microbial therapy, colonic drainage, and host-microbiota interaction research in the future.


Assuntos
Colonoscopia , Intubação Gastrointestinal , Animais , Colonoscopia/métodos , Suínos , Intubação Gastrointestinal/métodos , Nutrição Enteral/métodos , Nutrição Enteral/instrumentação , Imãs , Colo/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Duração da Cirurgia
11.
Environ Sci Technol ; 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39133145

RESUMO

In the pursuit of carbon neutrality, China's 2060 targets have been largely anchored in reducing greenhouse gas emissions, with less emphasis on the consequential benefits for air quality and public health. This study pivots to this critical nexus, exploring how China's carbon neutrality aligns with the World Health Organization's air quality guidelines (WHO AQG) regarding fine particulate matter (PM2.5) exposure. Coupling a technology-rich integrated assessment model, an emission-concentration response surface model, and exposure and health assessment, we find that decarbonization reduces sulfur dioxide (SO2), nitrogen oxides (NOx), and PM2.5 emissions by more than 90%; reduces nonmethane volatile organic compounds (NMVOCs) by more than 50%; and simultaneously reduces the disparities across regions. Critically, our analysis reveals that further targeted reductions in air pollutants, notably NH3 and non-energy-related NMVOCs, could bring most Chinese cities into attainment of WHO AQG for PM2.5 5 to 10 years earlier than the pathway focused solely on carbon neutrality. Thus, the integration of air pollution control measures into carbon neutrality strategies will present a significant opportunity for China to attain health and environmental equality.

12.
Cereb Cortex ; 33(4): 959-968, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-35348637

RESUMO

OBJECTIVE: Previous studies have revealed that, compared with Parkinson's disease (PD) patients without freezing of gait (FoG), the ones with FoG showed greater prefrontal activation while doing lower-limb movements involving standing, walking and turning, which require both locomotor and balance control. However, the relation between FoG and pure locomotor control as well as its underlying mechanism remain unclear. METHODS: A total of 56 PD subjects were recruited and allocated to PD-FoG and PD-noFoG subgroups, and 34 age-matched heathy adults were included as heathy control (HC). Functional near-infrared spectroscopy was used to measure their prefrontal activation in a sitting lower-limb movement task, wherein subjects were asked to sit and tap their right toes as big and as fast as possible. RESULTS: Result of one-way ANOVA (Group: PD-FoG vs. PD-noFoG vs. HC) revealed greater activation in the right prefrontal cortex in the PD-FoG group than in the other 2 groups. Linear mixed-effects model showed consistent result. Furthermore, the right prefrontal activation positively correlated with the severity of FoG symptoms in PD-FoG patients. CONCLUSION: These findings suggested that PD patients with FoG require additional cognitive resources to compensate their damaged automaticity in locomotor control, which is more pronounced in severe FoG patients than milder ones.


Assuntos
Transtornos Neurológicos da Marcha , Doença de Parkinson , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Transtornos Neurológicos da Marcha/diagnóstico por imagem , Transtornos Neurológicos da Marcha/etiologia , Postura Sentada , Marcha/fisiologia , Dedos do Pé
13.
Phytother Res ; 38(7): 3720-3735, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38776174

RESUMO

Idiopathic pulmonary fibrosis treatments are limited, often with severe side effects, highlighting the need for novel options. Taraxerone has diverse biomedical properties, but its mechanism remains unclear. This study investigates taraxerone's impact and the mechanisms involved in bleomycin-induced pulmonary fibrosis in mice. After establishing a pulmonary fibrosis mouse model, taraxerone was intraperitoneally injected continuously for 14-28 days. The in vivo antifibrotic and antioxidative stress effects of taraxerone were assessed. In vitro, the influence of taraxerone on transforming growth factor-ß1-induced myofibroblast transformation and oxidative stress was investigated. Subsequently, quantitative polymerase chain reaction screened the histone deacetylase and Sirtuin family, and taraxerone's effects on SIRT1 were assessed. After SIRT1 siRNA treatment, changes in myofibroblast transformation and antioxidant capacity in response to taraxerone were observed. Acetylation and phosphorylation levels of Smad3 were evaluated. We also examined the binding levels of SIRT1 with Pho-Smad3 and Smad3, as well as the nuclear localization of Smad2/3. EX527 confirmed SIRT1's in vivo action in response to taraxerone. In vitro experiments suggested that taraxerone inhibited myofibroblast differentiation by activating SIRT1 and reducing oxidative stress. We also observed a new interaction between SIRT1 and the Smad complex. Taraxerone activates SIRT1, enabling it to bind directly to Smad3. This leads to reduced Smad complex phosphorylation and limited nuclear translocation. As a result, the transcription of fibrotic factors is reduced. In vivo validation confirms taraxerone's SIRT1-mediated antifibrotic effectiveness. This suggests that targeting SIRT1-mediated inhibition of myofibroblast differentiation could be a key strategy in taraxerone-based therapy for pulmonary fibrosis.


Assuntos
Antioxidantes , Bleomicina , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Fibrose Pulmonar , Transdução de Sinais , Sirtuína 1 , Proteína Smad3 , Fator de Crescimento Transformador beta1 , Animais , Sirtuína 1/metabolismo , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/metabolismo , Camundongos , Transdução de Sinais/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteína Smad3/metabolismo , Antioxidantes/farmacologia , Masculino , Fator de Crescimento Transformador beta1/metabolismo , Miofibroblastos/efeitos dos fármacos , Miofibroblastos/metabolismo , Modelos Animais de Doenças , Fosforilação , Acetilação
14.
J Am Chem Soc ; 145(49): 26569-26579, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-38032297

RESUMO

The macrodaphniphyllamine-type, calyciphylline A-type, daphnilongeranin A-type, and daphnicyclidin D-type alkaloids are four structurally related classes of Daphniphyllum alkaloids. On the basis of a systematic analysis of the biogenetic network of these classes, we developed synthetic strategies centered on the C4-N and C1-C8 bonds of calyciphylline A, which took full advantage of the suitable substrates, reactions, and pathways that are altered from their counterparts in the postulated biogenetic network. Through this generalized biomimetic approach, we achieved the first synthesis of 14 Daphniphyllum alkaloids from the four subfamilies.


Assuntos
Alcaloides , Daphniphyllum , Estrutura Molecular , Alcaloides/química
15.
Small ; 19(2): e2205168, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36399644

RESUMO

Excessive anthropogenic CO2 emission has caused a series of ecological and environmental issues, which threatens mankind's sustainable development. Mimicking the natural photosynthesis process (i.e., artificial photosynthesis) by electrochemically converting CO2 into value-added products is a promising way to alleviate CO2 emission and relieve the dependence on fossil fuels. Recently, Sn-based catalysts have attracted increasing research attentions due to the merits of low price, abundance, non-toxicity, and environmental benignancy. In this review, the paradigm of nanostructure engineering for efficient electrochemical CO2 reduction (ECO2 R) on Sn-based catalysts is systematically summarized. First, the nanostructure engineering of size, composition, atomic structure, morphology, defect, surficial modification, catalyst/substrate interface, and single-atom structure, are systematically discussed. The influence of nanostructure engineering on the electronic structure and adsorption property of intermediates, as well as the performance of Sn-based catalysts for ECO2 R are highlighted. Second, the potential chemical state changes and the role of surface hydroxides on Sn-based catalysts during ECO2 R are introduced. Third, the challenges and opportunities of Sn-based catalysts for ECO2 R are proposed. It is expected that this review inspires the further development of highly efficient Sn-based catalysts, meanwhile offer protocols for the investigation of Sn-based catalysts.


Assuntos
Dióxido de Carbono , Nanoestruturas , Adsorção , Eletrônica , Engenharia
16.
Environ Sci Technol ; 57(33): 12453-12464, 2023 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-37561149

RESUMO

Hematite is a common iron oxide in natural environments, which has been observed to influence the transport and fate of arsenate by its association with hematite. Although oxygen vacancies were demonstrated to exist in hematite, their contributions to the arsenate immobilization have not been quantified. In this study, hematite samples with tunable oxygen vacancy defect (OVD) concentrations were synthesized by treating defect-free hematite using different NaBH4 solutions. The vacancy defects were characterized by positron annihilation lifetime spectroscopy, Doppler broadening of annihilation radiation, extended X-ray absorption fine structure (EXAFS), thermogravimetric mass spectrometry (TG-MS), electron paramagnetic resonance (EPR), and X-ray photoelectron spectroscopy (XPS). The results revealed that oxygen vacancy was the primary defect type existing on the hematite surface. TG-MS combined with EPR analysis allowed quantification of OVD concentrations in hematite. Batch experiments revealed that OVDs had a positive effect on arsenate adsorption, which could be quantitatively described by a linear relationship between the OVD concentration (Cdef, mmol m-2) and the enhanced arsenate adsorption amount caused by defects (ΔQm, µmol m-2) (ΔQm = 20.94 Cdef, R2 = 0.9813). NH3-diffuse reflectance infrared Fourier transform (NH3-DRIFT) analysis and density functional theory (DFT) calculations demonstrated that OVDs in hematite were beneficial to the improvement in adsorption strength of surface-active sites, thus considerably promoting the immobilization of arsenate.


Assuntos
Arseniatos , Compostos Férricos , Compostos Férricos/química , Adsorção
17.
Cardiovasc Drugs Ther ; 37(1): 25-37, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-34499283

RESUMO

PURPOSE: Nonsteroidal anti-inflammatory drugs (NSAIDs) are among one of the most commonly prescribed medications for pain and inflammation. Diclofenac (DIC) is a commonly prescribed NSAID that is known to increase the risk of cardiovascular diseases. However, the mechanisms underlying its cardiotoxic effects remain largely unknown. In this study, we tested the hypothesis that chronic exposure to DIC increases oxidative stress, which ultimately impairs cardiovascular function. METHODS AND RESULTS: Mice were treated with DIC for 4 weeks and subsequently subjected to in vivo and in vitro functional assessments. Chronic DIC exposure resulted in not only systolic but also diastolic dysfunction. DIC treatment, however, did not alter blood pressure or electrocardiographic recordings. Importantly, treatment with DIC significantly increased inflammatory cytokines and chemokines as well as cardiac fibroblast activation and proliferation. There was increased reactive oxygen species (ROS) production in cardiomyocytes from DIC-treated mice, which may contribute to the more depolarized mitochondrial membrane potential and reduced energy production, leading to a significant decrease in sarcoplasmic reticulum (SR) Ca2+ load, Ca2+ transients, and sarcomere shortening. Using unbiased metabolomic analyses, we demonstrated significant alterations in oxylipin profiles towards inflammatory features in chronic DIC treatment. CONCLUSIONS: Together, chronic treatment with DIC resulted in severe cardiotoxicity, which was mediated, in part, by an increase in mitochondrial oxidative stress.


Assuntos
Diclofenaco , Cardiopatias , Camundongos , Animais , Diclofenaco/toxicidade , Diclofenaco/metabolismo , Mediadores da Inflamação/metabolismo , Cardiopatias/induzido quimicamente , Cardiopatias/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Cardiotoxicidade , Miócitos Cardíacos , Anti-Inflamatórios não Esteroides/toxicidade
18.
Bioorg Chem ; 141: 106922, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37865056

RESUMO

The broad-spectrum antimicrobial ability of de novo designed amphiphilic antimicrobial peptides (AMPs) G(IIKK)3I-NH2 (G3) and C8-G(IIKK)2I-NH2 (C8G2) have been demonstrated. Nonetheless, their potential as anti-quorum-sensing (anti-QS) agents, particularly against the opportunistic pathogen Pseudomonas aeruginosa at subinhibitory concentrations, has received limited attention. In this study, we proved that treating P. aeruginosa PAO1 with both AMPs at subinhibitory concentrations led to significant inhibition of QS-regulated virulence factors, including pyocyanin, elastase, proteases, and bacterial motility. Additionally, the AMPs exhibited remarkable capabilities in suppressing biofilm formation and their elimination rate of mature biofilm exceeded 95%. Moreover, both AMPs substantially downregulated the expression of QS-related genes. CD analysis revealed that both AMPs induced structural alterations in the important QS-related protein LasR in vitro. Molecular docking results indicated that both peptides bind to the hydrophobic groove of the LasR dimer. Notably, upon mutating key binding sites (D5, E11, and F87) to Ala, the binding efficiency of LasR to both peptides significantly decreased. We revealed the potential of antibacterial peptides G3 and C8G2 at their sub-MIC concentrations as QS inhibitors against P. aeruginosa and elucidated their action mechanism. These findings contribute to our understanding of the therapeutic potential of these peptides in combating P. aeruginosa infections by targeting the QS system.


Assuntos
Peptídeos Antimicrobianos , Pseudomonas aeruginosa , Pseudomonas aeruginosa/fisiologia , Simulação de Acoplamento Molecular , Percepção de Quorum , Biofilmes , Antibacterianos/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo
19.
Proc Natl Acad Sci U S A ; 117(47): 29535-29542, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33168731

RESUMO

China is challenged with the simultaneous goals of improving air quality and mitigating climate change. The "Beautiful China" strategy, launched by the Chinese government in 2020, requires that all cities in China attain 35 µg/m3 or below for annual mean concentration of PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) by 2035. Meanwhile, China adopts a portfolio of low-carbon policies to meet its Nationally Determined Contribution (NDC) pledged in the Paris Agreement. Previous studies demonstrated the cobenefits to air pollution reduction from implementing low-carbon energy policies. Pathways for China to achieve dual targets of both air quality and CO2 mitigation, however, have not been comprehensively explored. Here, we couple an integrated assessment model and an air quality model to evaluate air quality in China through 2035 under the NDC scenario and an alternative scenario (Co-Benefit Energy [CBE]) with enhanced low-carbon policies. Results indicate that some Chinese cities cannot meet the PM2.5 target under the NDC scenario by 2035, even with the strictest end-of-pipe controls. Achieving the air quality target would require further reduction in emissions of multiple air pollutants by 6 to 32%, driving additional 22% reduction in CO2 emissions relative to the NDC scenario. Results show that the incremental health benefit from improved air quality of CBE exceeds 8 times the additional costs of CO2 mitigation, attributed particularly to the cost-effective reduction in household PM2.5 exposure. The additional low-carbon energy polices required for China's air quality targets would lay an important foundation for its deep decarbonization aligned with the 2 °C global temperature target.


Assuntos
Poluição do Ar/análise , Dióxido de Carbono/química , Poluentes Atmosféricos/efeitos adversos , Carbono/química , China , Cidades , Mudança Climática , Monitoramento Ambiental/métodos , Humanos , Paris , Material Particulado/química
20.
Altern Ther Health Med ; 29(8): 704-709, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37708538

RESUMO

Objective: Abundant angiogenesis in hepatocellular carcinoma (HCC) is critical in its malignant course; however, its mechanism is incompletely understood. Meanwhile, the corresponding roles of PIK3R6 molecules in HCC have not been investigated. This study aims to explore the intrinsic mechanism of PIK3R6 and provide theoretical reference for the treatment of hepatocellular carcinoma. Methods: Differential expressions of PIK in ovarian cancer and normal ones were detected by Western blotting and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Analyze the relationship between the expression of PIK3R6 and patient prognosis through the TCGA database. Subsequently constructed corresponding stable cell lines, combined with transcriptome sequencing and several cell biology experiments, we explored the inner mechanism and clinical significance of PIK3R6. Results: By analyzing multiple cohorts, we found that high PIK3R6 expression in tumor tissues negatively correlates with patient prognosis. PIK3R6 could increase angiogenesis in HCC by boosting the activity of the STAT3 signalling pathway to hasten the malignant progression of the disease, according to corresponding cellular and molecular experimental studies. Then again, immunohistochemistry on a series of tissue chips confirmed the important clinical significance of PIK3R6-STAT3 regulatory axis. Couclusions: This study initially addressed the clinical significance of PIK3R6 and revealed its mechanism for promoting angiogenesis in hepatocellular carcinoma, providing a reliable working foundation for future in-depth research and clinical translation.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Transdução de Sinais , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo
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