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1.
Nature ; 585(7823): 129-134, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32848250

RESUMO

Transmembrane channels and pores have key roles in fundamental biological processes1 and in biotechnological applications such as DNA nanopore sequencing2-4, resulting in considerable interest in the design of pore-containing proteins. Synthetic amphiphilic peptides have been found to form ion channels5,6, and there have been recent advances in de novo membrane protein design7,8 and in redesigning naturally occurring channel-containing proteins9,10. However, the de novo design of stable, well-defined transmembrane protein pores that are capable of conducting ions selectively or are large enough to enable the passage of small-molecule fluorophores remains an outstanding challenge11,12. Here we report the computational design of protein pores formed by two concentric rings of α-helices that are stable and monodisperse in both their water-soluble and their transmembrane forms. Crystal structures of the water-soluble forms of a 12-helical pore and a 16-helical pore closely match the computational design models. Patch-clamp electrophysiology experiments show that, when expressed in insect cells, the transmembrane form of the 12-helix pore enables the passage of ions across the membrane with high selectivity for potassium over sodium; ion passage is blocked by specific chemical modification at the pore entrance. When incorporated into liposomes using in vitro protein synthesis, the transmembrane form of the 16-helix pore-but not the 12-helix pore-enables the passage of biotinylated Alexa Fluor 488. A cryo-electron microscopy structure of the 16-helix transmembrane pore closely matches the design model. The ability to produce structurally and functionally well-defined transmembrane pores opens the door to the creation of designer channels and pores for a wide variety of applications.


Assuntos
Simulação por Computador , Genes Sintéticos/genética , Canais Iônicos/química , Canais Iônicos/genética , Modelos Moleculares , Biologia Sintética , Linhagem Celular , Microscopia Crioeletrônica , Cristalografia por Raios X , Condutividade Elétrica , Escherichia coli/genética , Escherichia coli/metabolismo , Hidrazinas , Canais Iônicos/metabolismo , Transporte de Íons , Lipossomos/metabolismo , Técnicas de Patch-Clamp , Porinas/química , Porinas/genética , Porinas/metabolismo , Engenharia de Proteínas , Estrutura Secundária de Proteína , Solubilidade , Água/química
2.
Nature ; 561(7724): 485-491, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30209393

RESUMO

The regular arrangements of ß-strands around a central axis in ß-barrels and of α-helices in coiled coils contrast with the irregular tertiary structures of most globular proteins, and have fascinated structural biologists since they were first discovered. Simple parametric models have been used to design a wide range of α-helical coiled-coil structures, but to date there has been no success with ß-barrels. Here we show that accurate de novo design of ß-barrels requires considerable symmetry-breaking to achieve continuous hydrogen-bond connectivity and eliminate backbone strain. We then build ensembles of ß-barrel backbone models with cavity shapes that match the fluorogenic compound DFHBI, and use a hierarchical grid-based search method to simultaneously optimize the rigid-body placement of DFHBI in these cavities and the identities of the surrounding amino acids to achieve high shape and chemical complementarity. The designs have high structural accuracy and bind and fluorescently activate DFHBI in vitro and in Escherichia coli, yeast and mammalian cells. This de novo design of small-molecule binding activity, using backbones custom-built to bind the ligand, should enable the design of increasingly sophisticated ligand-binding proteins, sensors and catalysts that are not limited by the backbone geometries available in known protein structures.


Assuntos
Compostos de Benzil/química , Fluorescência , Imidazolinas/química , Proteínas/química , Animais , Compostos de Benzil/análise , Células COS , Chlorocebus aethiops , Escherichia coli , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Ligação de Hidrogênio , Imidazolinas/análise , Ligantes , Ligação Proteica , Domínios Proteicos , Dobramento de Proteína , Estabilidade Proteica , Estrutura Secundária de Proteína , Reprodutibilidade dos Testes , Leveduras
3.
Phytother Res ; 38(8): 4009-4021, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38863408

RESUMO

Environmental pollution, virus infection, allergens, and other factors may cause respiratory disease, which could be improved by dietary therapy. Allium species are common daily food seasoning and have high nutritional and medical value. Diallyl disulfide (DADS) is the major volatile oil compound of Allium species. The present study aims to explore the preventive effect and potential mechanism of DADS on pulmonary fibrosis. C57BL/6J mice were intratracheally injected with bleomycin (BLM) to establish pulmonary fibrosis and then administrated with DADS. Primary lung fibroblasts or A549 were stimulated with BLM, followed by DADS, farnesoid X receptor (FXR) agonist (GW4064), yes-associated protein 1 (YAP1) inhibitor (verteporfin), or silencing of FXR and YAP1. In BLM-stimulated mice, DADS significantly ameliorated histopathological changes and interleukin-1ß levels in bronchoalveolar lavage fluid. DADS decreased fibrosis markers, HIF-1α, inflammatory cytokines, and epithelial-mesenchymal transition in pulmonary mice and activated fibroblasts. DADS significantly enhanced FXR expression and inhibited YAP1 activation, which functions as GW4064 and verteporfin. A deficiency of FXR or YAP1 could result in the increase of these two protein expressions, respectively. DADS ameliorated extracellular matrix deposition, hypoxia, epithelial-mesenchymal transition, and inflammation in FXR or YAP1 knockdown A549. Taken together, targeting the crosstalk of FXR and YAP1 might be the potential mechanism for DADS against pulmonary fibrosis. DADS can serve as a potential candidate or dietary nutraceutical supplement for the treatment of pulmonary fibrosis.


Assuntos
Compostos Alílicos , Dissulfetos , Camundongos Endogâmicos C57BL , Fibrose Pulmonar , Receptores Citoplasmáticos e Nucleares , Transdução de Sinais , Proteínas de Sinalização YAP , Animais , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/induzido quimicamente , Camundongos , Dissulfetos/farmacologia , Humanos , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais/efeitos dos fármacos , Compostos Alílicos/farmacologia , Células A549 , Masculino , Allium/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Bleomicina , Pulmão/efeitos dos fármacos , Pulmão/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo
4.
Phytother Res ; 35(10): 5680-5693, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34250656

RESUMO

The current study focused on the regulatory effects of parthenolide (PNL), a bioactive component derived from Chrysanthemum parthenium L., against hepatic fibrosis via regulating the crosstalk of toll-like receptor 4 (TLR4) and signal transducer and activator of transcription 3 (STAT3) in activated hepatic stellate cells (HSCs). HSCs or Raw 264.7 macrophages were activated by TGF-ß or LPS for 1 hr, respectively, and then treated with PNL, CLI-095 (TLR4 inhibitor), or Niclosamide (STAT3 inhibitor) for the indicated time to detect the crosstalk of TLR4 and STAT3. PNL significantly decreased the expressions of α-SMA, collagen I, and the ratio of TIMP1 and MMP13 in TGF-ß-activated HSCs. PNL significantly reduced the releases of pro-inflammatory cytokines, including IL-6, IL-1ß, IL-1α, IL-18, and regulated signaling P2X7r/NLRP3 axis activation. PNL obviously induced the apoptosis of activated HSCs by regulating bcl-2 and caspases family. PNL significantly inhibited the expressions of TLR4 and STAT3, including their downstream signaling. PNL could regulate the crosstalk of TLR4 and STAT3, which were verified by their inhibitors in activated HSCs or Raw 264.7 cell macrophages. Thus, PNL could decrease the expressions of fibrosis markers, reduce the releases of inflammatory cytokines, and also induce the apoptosis of activated HSCs. In conclusion, PNL could bi-directionally inhibit TLR4 and STAT3 signaling pathway, suggesting that blocking the crosstalk of TLR4 and STAT3 might be the potential mechanism of PNL against hepatic fibrosis.


Assuntos
Fator de Transcrição STAT3 , Receptor 4 Toll-Like , Inflamação , Cirrose Hepática/tratamento farmacológico , Fator de Transcrição STAT3/metabolismo , Sesquiterpenos , Transdução de Sinais , Tanacetum parthenium , Receptor 4 Toll-Like/metabolismo
5.
Nature ; 501(7466): 212-216, 2013 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-24005320

RESUMO

The ability to design proteins with high affinity and selectivity for any given small molecule is a rigorous test of our understanding of the physiochemical principles that govern molecular recognition. Attempts to rationally design ligand-binding proteins have met with little success, however, and the computational design of protein-small-molecule interfaces remains an unsolved problem. Current approaches for designing ligand-binding proteins for medical and biotechnological uses rely on raising antibodies against a target antigen in immunized animals and/or performing laboratory-directed evolution of proteins with an existing low affinity for the desired ligand, neither of which allows complete control over the interactions involved in binding. Here we describe a general computational method for designing pre-organized and shape complementary small-molecule-binding sites, and use it to generate protein binders to the steroid digoxigenin (DIG). Of seventeen experimentally characterized designs, two bind DIG; the model of the higher affinity binder has the most energetically favourable and pre-organized interface in the design set. A comprehensive binding-fitness landscape of this design, generated by library selections and deep sequencing, was used to optimize its binding affinity to a picomolar level, and X-ray co-crystal structures of two variants show atomic-level agreement with the corresponding computational models. The optimized binder is selective for DIG over the related steroids digitoxigenin, progesterone and ß-oestradiol, and this steroid binding preference can be reprogrammed by manipulation of explicitly designed hydrogen-bonding interactions. The computational design method presented here should enable the development of a new generation of biosensors, therapeutics and diagnostics.


Assuntos
Simulação por Computador , Digoxigenina/metabolismo , Desenho de Fármacos , Proteínas/química , Proteínas/metabolismo , Sítios de Ligação , Biotecnologia , Cristalografia por Raios X , Digoxigenina/química , Estradiol/química , Estradiol/metabolismo , Ligantes , Modelos Moleculares , Progesterona/química , Progesterona/metabolismo , Ligação Proteica , Reprodutibilidade dos Testes , Especificidade por Substrato
6.
J Chem Inf Model ; 56(6): 1022-31, 2016 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-26419257

RESUMO

Community Structure-Activity Resource (CSAR) conducted a benchmark exercise to evaluate the current computational methods for protein design, ligand docking, and scoring/ranking. The exercise consisted of three phases. The first phase required the participants to identify and rank order which designed sequences were able to bind the small molecule digoxigenin. The second phase challenged the community to select a near-native pose of digoxigenin from a set of decoy poses for two of the designed proteins. The third phase investigated the ability of current methods to rank/score the binding affinity of 10 related steroids to one of the designed proteins (pKd = 4.1 to 6.7). We found that 11 of 13 groups were able to correctly select the sequence that bound digoxigenin, with most groups providing the correct three-dimensional structure for the backbone of the protein as well as all atoms of the active-site residues. Eleven of the 14 groups were able to select the appropriate pose from a set of plausible decoy poses. The ability to predict absolute binding affinities is still a difficult task, as 8 of 14 groups were able to correlate scores to affinity (Pearson-r > 0.7) of the designed protein for congeneric steroids and only 5 of 14 groups were able to correlate the ranks of the 10 related ligands (Spearman-ρ > 0.7).


Assuntos
Desenho de Fármacos , Simulação de Acoplamento Molecular , Proteínas/metabolismo , Sequência de Aminoácidos , Benchmarking , Digoxigenina/química , Digoxigenina/metabolismo , Ligantes , Ligação Proteica , Conformação Proteica , Proteínas/química , Relação Estrutura-Atividade
7.
Phytomedicine ; 123: 155145, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37976698

RESUMO

BACKGROUND: Sesamol (SEM), a natural lignan compound isolated from sesame, has strong anti-oxidant property, regulating lipid metabolism, decreasing cholesterol and hepatoprotection. However, its anti-hepatic fibrosis effect and mechanisms have not been comprehensively elucidated. HYPOTHESIS/PURPOSE: This study aims to investigate the anti-hepatic fibrosis of SEM and its underlying mechanisms. METHOD: C57BL/6 mice with hepatic fibrosis were induced by TAA, then administrated with SEM or curcumin, respectively. HSCs were stimulated by TGF-ß or conditioned medium, and then cultured with SEM, GW4064, GW3965, Rapamycin (RA) or 3-methyladenine (3-MA), respectively. Mice with hepatic fibrosis also were administrated with SEM, RA or 3-MA to estimate the effect of SEM on autophagy. RESULTS: In vitro, SEM significantly inhibited extracellular matrix deposition, P2 × 7r-NLRP3, and inflammatory cytokines. SEM increased FXR and LXRα/ß expressions and decreased MAPLC3α/ß and P62 expressions, functioning as 3-MA (autophagy inhibitor). In vivo, SEM reduced serum transaminase, histopathology changes, fibrogenesis, autophagy markers and inflammatory cytokines caused by TAA. LX-2 were activated with conditioned medium from LPS-primed THP-1, which resulted in significant enhance of autophagy markers and inflammatory cytokines and decrease of FXR and LXRα/ß expressions. SEM could reverse above these changes and function as 3-MA, GW4064, or GW3965. Deficiency of FXR or LXR attenuated the regulation of SEM on α-SMA, MAPLC3α/ß, P62 and IL-1ß in activated LX-2. In activated THP-1, deficiency of FXR could decrease the expression of LXR, and vice versa. Deficiency of FXR or LXR in activated MΦ decreased the expressions of FXR and LXR in activated LX-2. Deficiency FXR or LXR in activated MΦ also attenuated the regulation of SEM on α-SMA, MAPLC3α/ß, P62, caspase-1 and IL-1ß. In vivo, SEM significantly reversed hepatic fibrosis via FXR/LXR and autophagy. CONCLUSION: SEM could regulate hepatic fibrosis by inhibiting fibrogenesis, autophagy and inflammation. FXR/LXR axis-mediated inhibition of autophagy contributed to the regulation of SEM against hepatic fibrosis, especially based on involving in the crosstalk of HSCs-macrophage. SEM might be a prospective therapeutic candidate, and its mechanism would be a new direction or strategy for hepatic fibrosis treatment.


Assuntos
Benzoatos , Benzodioxóis , Benzilaminas , Hepatócitos , Cirrose Hepática , Fenóis , Camundongos , Animais , Meios de Cultivo Condicionados/efeitos adversos , Meios de Cultivo Condicionados/metabolismo , Camundongos Endogâmicos C57BL , Cirrose Hepática/metabolismo , Hepatócitos/metabolismo , Macrófagos , Citocinas/metabolismo , Autofagia , Células Estreladas do Fígado , Fígado
8.
Food Funct ; 2024 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-39449622

RESUMO

Pterostilbene (PTE), a natural stilbene found in small berries, exhibits multiple pharmacological activities, particularly antioxidant and anti-inflammatory activities. This study explores the dietary supplementation of PTE to ameliorate acute and chronic alcohol-associated liver disease (ALD). C57BL/6 mice were administrated with PTE and subjected to acute or chronic alcohol stimulation. They were intragastrically administered with alcohol (5 g kg-1, 3 times per 24 h) to induce acute alcohol liver injury or fed a Lieber-DeCarli liquid diet containing 5% ethanol for 4 weeks and a single binge to induce chronic alcoholic liver injury. In the acute ethanol model, PTE decreased the serum transaminase and triglyceride (TG) levels and ameliorated lipid droplet accumulation. PTE ameliorated acute ethanol-induced hepatic steatosis by inhibiting the expression of SREBP1 and its target genes and up-regulating PPARα expression. PTE could reverse the inflammatory response by inhibiting NLRP3 activation, inflammatory factor secretion, and macrophage recruitment caused by acute ethanol exposure. PTE could synergistically activate the SIRT1-AMPK and LXR/FXR axis in mice with acute ethanol exposure. In the chronic-binge ethanol feeding model, PTE also decreased serum transaminase and TG levels and ameliorated hepatocellular ballooning, macrovesicular steatosis, lipid accumulation and inflammation. Chronic-binge ethanol feeding could induce extracellular matrix dysfunction with an increase in α-SMA, collagen I and TIMP-1 expression, which was decreased by PTE. PTE increased SIRT1 expression and AMPK phosphorylation and activated the LXRs/FXR axis, which could be reduced by chronic-binge ethanol feeding. PTE could prevent liver injury caused by alcohol regardless of acute or chronic exposure. These results suggest that PTE can be utilized as a dietary health supplement to avoid ALD and promote health and quality of life.

9.
Phytomedicine ; 135: 156144, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39405612

RESUMO

BACKGROUND: Astilbin (ATB), a natural dihydroflavonol compound, exists in many plants, processed and functional foods. ATB has multiple pharmacological effects, such as antioxidant, lipid-lowering, and hepatoprotective. However, its anti-hepatic fibrosis and mechanisms remain unclearly elucidated. PURPOSE: This study explored the effect of ATB against the hepatic fibrosis and its regulation of hepatic microenvironment by regulating hepatic stellate cells-macrophage crosstalk. METHOD: Thioacetamide (TAA) was intraperitoneal injected to establish hepatic fibrosis mice, and treated with ATB or curcumin by gavage, respectively. Hepatic stellate cells (HSCs) were stimulated with TGF-ß or conditioned medium (CM) from LPS-induced THP-1, then cultured with ATB, PXR agonist or antagonist. RESULTS: In TAA-induced mice, ATB improved histopathological changes, serum transaminases increase; alleviated extracellular matrix (ECM) deposition, epithelial-mesenchymal transformation (EMT), inflammatory infiltration, PTEN induced kinase 1 (PINK1)/Parkin-mediated mitophagy and activated pregnane X receptor (PXR) expression. In vitro, ATB significantly reduced ECM, inflammatory cytokines release, mitophagy, EMT, and activated PXR expression. ATB could increase PXR and decrease PINK1/Parkin, functioning as a PXR agonist. PXR deficiency in LX-2 could degrade the regulation of ATB on ECM, inflammation, EMT, and mitophagy. CM from LPS-induced THP-1 activated LX-2 and resulted in PXR decreasing, while ATB could regulate the crosstalk between HSCs and macrophages. Deficiency of PXR, whether in LX-2 or in macrophages, all weakened the inhibitory effect of ATB on α-SMA, EMT, inflammatory cytokines, and PINK1/Parkin signaling. CONCLUSION: ATB ameliorated hepatic fibrosis by inhibiting HSCs activation, inflammation and EMT through PXR-mediated PINK1/Parkin signaling. Especially, ATB targeted the hepatic microenvironment between hepatic stellate cells and macrophages, which might be a promising strategy for the treatment of hepatic fibrosis.

10.
J Agric Food Chem ; 72(28): 15740-15754, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38970822

RESUMO

Hepatic fibrosis is a compensatory response to chronic liver injury and inflammation, and dietary intervention is recommended as one of the fundamental prevention strategies. Raspberry ketone (RK) is an aromatic compound first isolated from raspberry and widely used to prepare food flavors. The current study investigated the hepatoprotection and potential mechanism of RK against hepatic fibrosis. In vitro, hepatic stellate cell (HSC) activation was stimulated with TGF-ß and cultured with RK, farnesoid X receptor (FXR), or peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) agonist or inhibitor, respectively. In vivo, C57BL/6 mice were injected intraperitoneally with thioacetamide (TAA) at 100/200 mg/kg from the first to the fifth week. Mice were intragastrically administrated with RK or Cur once a day from the second to the fifth week. In activated HSCs, RK inhibited extracellular matrix (ECM) accumulation, inflammation, and epithelial-mesenchymal transition (EMT) process. RK both activated FXR/PGC-1α and regulated their crosstalk, which were verified by their inhibitors and agonists. Deficiency of FXR or PGC-1α also attenuated the effect of RK on the reverse of activated HSCs. RK also decreased serum ALT/AST levels, liver histopathological change, ECM accumulation, inflammation, and EMT in mice caused by TAA. Double activation of FXR/PGC-1α might be the key targets for RK against hepatic fibrosis. Above all, these discoveries supported the potential of RK as a novel candidate for the dietary intervention of hepatic fibrosis.


Assuntos
Butanonas , Células Estreladas do Fígado , Cirrose Hepática , Camundongos Endogâmicos C57BL , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Receptores Citoplasmáticos e Nucleares , Transdução de Sinais , Animais , Humanos , Masculino , Camundongos , Butanonas/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/efeitos dos fármacos , Inflamação/metabolismo , Inflamação/tratamento farmacológico , Cirrose Hepática/metabolismo , Cirrose Hepática/genética , Cirrose Hepática/tratamento farmacológico , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Rubus/química , Transdução de Sinais/efeitos dos fármacos , Ratos
11.
J Nat Med ; 78(2): 427-438, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38334900

RESUMO

Angelica dahurica (A. dahurica) has a wide range of pharmacological effects, including analgesic, anti-inflammatory and hepatoprotective effects. In this study, we investigated the effect of A. dahurica extract (AD) and its effective component bergapten (BG) on hepatic fibrosis and potential mechanisms. Hepatic fibrosis was induced by intraperitoneal injection with carbon tetrachloride (CCl4) for 1 week, and mice were administrated with AD or BG by gavage for 1 week before CCl4 injection. Hepatic stellate cells (HSCs) were stimulated by transforming growth factor-ß (TGF-ß) and cultured with AD, BG, GW4064 (FXR agonist) or Guggulsterone (FXR inhibitor). In CCl4-induced mice, AD significantly decreased serum aminotransferase, reduced excess accumulation of extracellular matrix (ECM), inhibited caspase-1 and IL-1ß, and increased FXR expressions. In activated HSCs, AD suppressed the expressions of α-SMA, collagen I, and TIMP-1/MMP-13 ratio and inflammatory factors, functioning as FXR agonist. In CCl4-induced mice, BG significantly improved serum transaminase and histopathological changes, reduced ECM excessive deposition, inflammatory response, and activated FXR expression. BG increased FXR expression and inhibited α-SMA and IL-1ß expressions in activated HSCs, functioning as GW4064. FXR deficiency significantly attenuated the decreasing effect of BG on α-SMA and IL-1ß expressions in LX-2 cells. In conclusion, AD could regulate hepatic fibrosis by regulating ECM excessive deposition and inflammation. Activating FXR signaling by BG might be the potential mechanism of AD against hepatic fibrosis.


Assuntos
Cirrose Hepática , Transdução de Sinais , Camundongos , Animais , 5-Metoxipsoraleno/efeitos adversos , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Células Estreladas do Fígado , Fator de Crescimento Transformador beta/farmacologia , Fígado
12.
Sci Adv ; 9(32): eadi1870, 2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37556541

RESUMO

Multicellular biological systems, particularly living neural networks, exhibit highly complex organization properties that pose difficulties for building cell-specific biocompatible interfaces. We previously developed an approach to genetically program cells to assemble structures that modify electrical properties of neurons in situ, opening up the possibility of building minimally invasive cell-specific structures and interfaces. However, the efficiency and biocompatibility of this approach were challenged by limited membrane targeting of the constructed materials. Here, we design a method for highly localized expression of enzymes targeted to the plasma membrane of primary neurons, with minimal intracellular retention. Next, we show that polymers synthesized in situ by this approach form dense extracellular clusters selectively on the targeted cell membrane and that neurons remain viable after polymerization. Last, we show generalizability of this method across a range of design strategies. This platform can be readily extended to incorporate a broad diversity of materials onto specific cell membranes within tissues and may further enable next-generation biological interfaces.


Assuntos
Neurônios , Polímeros , Polímeros/química , Neurônios/fisiologia , Membrana Celular/metabolismo , Materiais Biocompatíveis/química
13.
Food Chem Toxicol ; 181: 114042, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37722617

RESUMO

Pterostilbene (PTE), a natural analogue of resveratrol, abundantly exists in blueberries and grapes and has several beneficial potentials against oxidative stress, inflammation, and cancer. In current study, we investigated the effects of PTE on hepatic fibrosis in vitro and in vivo. Activation of hepatic stellate cells (HSCs) is an initiating event in the initiation of hepatic fibrosis. MTT assay revealed that PTE (3.125-12.5 µM) displayed cytotoxicity on activated HSCs, no cytotoxicity on AML-12 and quiescent HSCs. PTE significantly inhibited the expressions of α-SMA, collagen Ⅰ and TIMP-1/MMP13 ratio; suppressed inflammatory cascade activation to reduce inflammatory cytokines release, such as Caspase-1, IL-1ß and IL-6. PTE activated Sirt1 and decreased STAT3 phosphorylation, functioning as SRT1720 and Niclosamide. Sirt1 deficiency significantly elevated p-STAT3 expression, while STAT3 deficiency resulted in Sirt1 increasing and inhibited fibrosis and inflammatory cytokines expressions. In mice with hepatic fibrosis induced by thioacetamide (TAA), PTE significantly decreased ALT and AST activities, reduced fibrosis markers, STAT3 phosphorylation and activated Sirt1 expression. PTE showed cytotoxicity on activated HSCs to ameliorate hepatic fibrosis via regulating fibrogenesis, energy metabolism and inflammation and targeting the crosstalk of Sirt1 and STAT3. In conclusion, PTE could be potentially beneficial as a natural plant metabolite in preventing and treating hepatic fibrosis.


Assuntos
Células Estreladas do Fígado , Sirtuína 1 , Camundongos , Animais , Sirtuína 1/genética , Sirtuína 1/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Fibrose , Inflamação/metabolismo , Proliferação de Células , Citocinas/metabolismo
14.
Phytochemistry ; 200: 113247, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35597316

RESUMO

Acanthoic acid (AA) is a pimaradiene diterpene isolated from the root bark of Acanthopanax koreanum Nakai (Araliaceae) with a wide range of pharmacological activities, including anti-cancer, anti-inflammatory, anti-diabetes, liver protection, gastrointestinal protection, and cardiovascular protection. In addition, AA promotes its pharmacological effects by targeting liver X receptors (LXRs), nuclear factor-kappa B (NF-κB), Toll-Like Receptor 4 (TLR4) and IL-1 receptor-associated kinase (IRAK) signaling pathways, or AMP-activated protein kinase (AMPK) signaling pathway, etc. Also, some studies focus on the structural modification of AA to improve its pharmacological activities. The review summarizes the pharmacological activities, molecular mechanism, and the structural modification of AA, which might supply information for the development of AA in the future.


Assuntos
Araliaceae , Diterpenos , Eleutherococcus , Anti-Inflamatórios/farmacologia , Diterpenos/química , Diterpenos/farmacologia , Eleutherococcus/química , NF-kappa B/metabolismo
15.
Biomol Ther (Seoul) ; 30(3): 246-256, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34815367

RESUMO

The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 µM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.

16.
Food Funct ; 13(8): 4678-4690, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35377371

RESUMO

Siberian onions (SOs) are delicious wild vegetables. Their taste is most unique, not only like scallions but also like leeks or garlic. They also have a traditional medicinal value for anti-inflammation, anti-oxidation, and anti-pyretic analgesia, particularly facilitating hepatoprotective effects. The current study investigates the potential mechanism of SOs against toxin-induced liver dysfunction. BALB/c mice were administrated with SO or silymarin by oral gavage for one week, followed by injecting carbon tetrachloride (CCl4) to induce hepatic fibrosis. The effect of SO against hepatic fibrosis was evaluated by examining the liver tissue for serum transaminase, oxidative stress, extracellular matrix, histological alterations, cytokine levels, and apoptosis. In vitro, HSC-T6 cells were cultured with the supernatant from Raw 264.7 cells stimulated with lipopolysaccharides, followed by SO extracts or Niclosamide (Signal Transducer and Activator of Transcription 3 (STAT3) inhibitor) at indicated time periods and doses. SO decreased serum transaminase levels and oxidative stress, and regulated the balance of ECM in CCl4-induced mice, including α-SMA, collagen-I and TIMP-1. SO reduced the release of inflammatory factors and regulated apoptosis-associated proteins, which is related to the inhibition of STAT3 phosphorylation. Moreover, SO reduced the positive expressions of α-SMA and NLRP3 by inhibiting STAT3 phosphorylation in activated HSCs. SO could show health-promoting effects for liver dysfunction by alleviating hepatic fibrogenesis, apoptosis and inflammation in the development of hepatic fibrosis potential depending on the STAT3 signaling pathway.


Assuntos
Tetracloreto de Carbono , Cebolas , Animais , Tetracloreto de Carbono/efeitos adversos , Células Estreladas do Fígado , Fígado/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/genética , Camundongos , Transaminases/metabolismo
17.
Zhongguo Yi Liao Qi Xie Za Zhi ; 35(1): 6-10, 2011 Jan.
Artigo em Zh | MEDLINE | ID: mdl-21553528

RESUMO

Based on Moens-Korteweg model & hydrostatic principle, a simple calibration method by changing vertical distance between heart and radial artery is proposed in this paper. Using hydrostatic pressure to change arterial pressure and pulse wave transmit time, consequently obtain several sets of cardiovascular parameters and finally build up relationship between blood pressure and pulse wave transmit time. Clinical tests have been carried with different age and gender for long and short time monitoring. The comparison results with Sphygmomanometer OMRON EW3152 show its promising accuracy and coincidence feature in blood pressure measurement.


Assuntos
Determinação da Pressão Arterial/instrumentação , Determinação da Pressão Arterial/métodos , Monitores de Pressão Arterial , Calibragem , Desenho de Equipamento
18.
Front Pharmacol ; 12: 738689, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34690775

RESUMO

Allium victorialis L. (AVL) is a traditional medicinal plant recorded in the Compendium of Materia Medica (the Ming Dynasty). In general, it is used for hemostasis, analgesia, anti-inflammation, antioxidation, and to especially facilitate hepatoprotective effect. In recent years, it has received more and more attention due to its special nutritional and medicinal value. The present study investigates the effect and potential mechanism of AVL against alcoholic liver disease (ALD). C57BL/6 mice were fed Lieber-DeCarli liquid diet containing 5% ethanol plus a single ethanol gavage (5 g/kg), and followed up with the administration of AVL or silymarin. AML12 cells were stimulated with ethanol and incubated with AVL. AVL significantly reduced serum transaminase and triglycerides in the liver and attenuated histopathological changes caused by ethanol. AVL significantly inhibited SREBP1 and its target genes, regulated lipin 1/2, increased PPARα and its target genes, and decreased PPARγ expression caused by ethanol. In addition, AVL significantly enhanced FXR, LXRs, Sirt1, and AMPK expressions compared with the EtOH group. AVL also inhibited inflammatory factors, NLRP3, and F4/80 and MPO, macrophage and neutrophil markers. In vitro, AVL significantly reduced lipid droplets, lipid metabolism enzymes, and inflammatory factors depending on FXR activation. AVL could ameliorate alcoholic steatohepatitis, lipid deposition and inflammation in ALD by targeting FXR activation.

19.
Nat Commun ; 12(1): 856, 2021 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-33558528

RESUMO

Through the efforts of many groups, a wide range of fluorescent protein reporters and sensors based on green fluorescent protein and its relatives have been engineered in recent years. Here we explore the incorporation of sensing modalities into de novo designed fluorescence-activating proteins, called mini-fluorescence-activating proteins (mFAPs), that bind and stabilize the fluorescent cis-planar state of the fluorogenic compound DFHBI. We show through further design that the fluorescence intensity and specificity of mFAPs for different chromophores can be tuned, and the fluorescence made sensitive to pH and Ca2+ for real-time fluorescence reporting. Bipartite split mFAPs enable real-time monitoring of protein-protein association and (unlike widely used split GFP reporter systems) are fully reversible, allowing direct readout of association and dissociation events. The relative ease with which sensing modalities can be incorporated and advantages in smaller size and photostability make de novo designed fluorescence-activating proteins attractive candidates for optical sensor engineering.


Assuntos
Proteínas Luminescentes/metabolismo , Acetilcolina/metabolismo , Animais , Células COS , Cálcio/metabolismo , Chlorocebus aethiops , Fluorescência , Corantes Fluorescentes/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Proteínas Luminescentes/química , Modelos Moleculares
20.
Mol Syst Des Eng ; 5(1): 349-357, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35265342

RESUMO

Genetic selection combined with next-generation sequencing enables the simultaneous interrogation of the functionality and stability of large numbers of naturally occurring, engineered, or computationally designed protein variants in parallel. We display hundreds of engineered proteins on the surface of yeast cells, select for binding to a set of target molecules by flow cytometry, and sequence the starting pool as well as selected pools to obtain enrichment values for each displayed protein with each target. We show that this high-throughput workflow of multiplex genetic selections followed by large-scale sequencing and comparative analysis allows not only the determination of relative affinities, but also the monitoring of specificity profiles for hundreds to thousands of protein-protein and protein-small molecule interactions in parallel. The approach not only identifies new interactions of designed proteins, but also detects unintended and undesirable off-target interactions. This provides a general framework for screening of engineered protein binders, which often have no negative selection or design step as part of their development pipelines. Hence, this method will be generally useful in the development of protein-based therapeutics.

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