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1.
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease with multiple causes, characterized by excessive myofibrocyte aggregation and extracellular matrix deposition. Related studies have shown that transforming growth factor-β1 (TGF-β1) is a key cytokine causing fibrosis, promoting abnormal epithelial–mesenchymal communication and fibroblast-to-myofibroblast transition. Fedratinib (Fed) is a marketed drug for the treatment of primary and secondary myelofibrosis, targeting selective JAK2 tyrosine kinase inhibitors. However, its role in pulmonary fibrosis remains unclear. In this study, we investigated the potential effects and mechanisms of Fed on pulmonary fibrosis in vitro and in vivo. In vitro studies have shown that Fed attenuates TGF-β1- and IL-6-induced myofibroblast activation and inflammatory response by regulating the JAK2/STAT3 signaling pathway. In vivo studies have shown that Fed can reduce bleomycin-induced inflammation and collagen deposition and improve lung function. In conclusion, Fed inhibited inflammation and fibrosis processes induced by TGF-β1 and IL-6 by targeting the JAK2 receptor.  相似文献   

2.
Various studies addressing the increasing problem of hair loss, using natural products with few side effects, have been conducted. 5-bromo-3,4-dihydroxybenzaldehyde (BDB) exhibited anti-inflammatory effects in mouse models of atopic dermatitis and inhibited UVB-induced oxidative stress in keratinocytes. Here, we investigated its stimulating effect and the underlying mechanism of action on hair growth using rat vibrissa follicles and dermal papilla cells (DPCs), required for the regulation of hair cycle and length. BDB increased the length of hair fibers in rat vibrissa follicles and the proliferation of DPCs, along with causing changes in the levels of cell cycle-related proteins. We investigated whether BDB could trigger anagen-activating signaling pathways, such as the Wnt/β-catenin pathway and autophagy in DPCs. BDB induces activation of the Wnt/β-catenin pathway through the phosphorylation of GSG3β and β-catenin. BDB increased the levels of autophagic vacuoles and autophagy regulatory proteins Atg7, Atg5, Atg16L, and LC3B. We also investigated whether BDB inhibits the TGF-β pathway, which promotes transition to the catagen phase. BDB inhibited the phosphorylation of Smad2 induced by TGF-β1. Thus, BDB can promote hair growth by modulating anagen signaling by activating Wnt/β-catenin and autophagy pathways and inhibiting the TGF-β pathway in DPCs.  相似文献   

3.
Osteoarthritis is characterized by structural alteration of joints. Fibrosis of the synovial tissue is often detected and considered one of the main causes of joint stiffness and pain. In our earlier proteomic study, increased levels of vitronectin (VTN) fragment (amino acids 381–397) were observed in the serum of osteoarthritis patients. In this work, the affinity of this fragment for integrins and its putative role in TGF-β1 activation were investigated. A competition study determined the interaction of VTN(381–397 a.a.) with αVβ6 integrin. Subsequently, the presence of αVβ6 integrin was substantiated on primary human fibroblast-like synoviocytes (FLSs) by western blot and flow cytometry. By immunohistochemistry, β6 was detected in synovial membranes, and its expression showed a correlation with tissue fibrosis. Moreover, β6 expression was increased under TGF-β1 stimulation; hence, a TGF-β bioassay was applied. We observed that αVβ6 could mediate TGF-β1 bioavailability and that VTN(381–397 a.a.) could prevent TGF-β1 activation by interacting with αVβ6 in human FLSs and increased α-SMA. Finally, we analyzed serum samples from healthy controls and patients with osteoarthritis and other rheumatic diseases by nano-LC/Chip MS–MS, confirming the increased expression of VTN(381–397 a.a.) in osteoarthritis as well as in lupus erythematosus and systemic sclerosis. These findings corroborate our previous observations concerning the overexpression of VTN(381–397 a.a.) in osteoarthritis but also in other rheumatic diseases. This fragment interacts with αVβ6 integrin, a receptor whose expression is increased in FLSs from the osteoarthritic synovial membrane and that can mediate the activation of the TGF-β1 precursor in human FLSs.Subject terms: Osteoarthritis, Cell culture  相似文献   

4.
Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening lung disease characterized by the proliferation of myofibroblasts and deposition of extracellular matrix that results in irreversible distortion of the lung structure and the formation of focal fibrosis. The molecular mechanism of IPF is not fully understood, and there is no satisfactory treatment. However, most studies suggest that abnormal activation of transforming growth factor-β1 (TGF-β1) can promote fibroblast activation and epithelial to mesenchymal transition (EMT) to induce pulmonary fibrosis. Deglycosylated azithromycin (Deg-AZM) is a compound we previously obtained by removing glycosyls from azithromycin; it was demonstrated to exert little or no antibacterial effects. Here, we discovered a new function of Deg-AZM in pulmonary fibrosis. In vivo experiments showed that Deg-AZM could significantly reduce bleomycin-induced pulmonary fibrosis and restore respiratory function. Further study revealed the anti-inflammatory and antioxidant effects of Deg-AZM in vivo. In vitro experiments showed that Deg-AZM inhibited TGF-β1 signaling, weakened the activation and differentiation of lung fibroblasts, and inhibited TGF-β1-induced EMT in alveolar epithelial cells. In conclusion, our findings show that Deg-AZM exerts antifibrotic effects by inhibiting TGF-β1-induced myofibroblast activation and EMT.  相似文献   

5.
In the present study, we investigated the molecular mechanisms of adenosine for its hair growth promoting effect. Adenosine stimulated the Wnt/β-catenin pathway by modulating the activity of Gsk3β in cultured human dermal papilla cells. It also activated adenosine receptor signaling, increasing intracellular cAMP level, and subsequently stimulating the cAMP mediated cellular energy metabolism. The phosphorylation of CREB, mTOR, and GSK3β was increased. Furthermore, the expression of β-catenin target genes such as Axin2, Lef1, and growth factors (bFGF, FGF7, IGF-1) was also enhanced. The inhibitor study data conducted in Wnt reporter cells and in cultured human dermal papilla cells demonstrated that adenosine stimulates Wnt/β-catenin signaling through the activation of the adenosine receptor and Gsk3β plays a critical role in transmitting the signals from the adenosine receptor to β-catenin, possibly via the Gαs/cAMP/PKA/mTOR signaling cascade.  相似文献   

6.
7.
Previous studies have reported that recombinant tumor necrosis factor (TNF)-α has powerful antiviral activity but severe systematic side effects. Jasminin is a common bioactive component found in Chinese herbal medicine beverage “Jasmine Tea”. Here, we report that jasminin-induced endogenous TNF-α showed antiviral activity in vitro. The underlying TNF-α-inducing action of jasminin was also investigated in RAW264.7 cells. The level of endogenous TNF-α stimulated by jasminin was first analyzed by an enzyme-linked immunosorbent assay (ELISA) from the cell culture supernatant of RAW264.7 cells. The supernatants were then collected to investigate the potential antiviral effect against herpes simplex virus 1 (HSV-1). The antiviral effects of jasminin alone or its supernatants were evaluated by a plaque reduction assay. The potential activation of the PI3K–Akt pathway, three main mitogen-activated protein kinases (MAPKs), and nuclear factor (NF)–κB signaling pathways that induce TNF-α production were also investigated. Jasminin induces TNF-α protein expression in RAW264.7 cells without additional stimuli 10-fold more than the control. No significant up-expression of type I, II, and III interferons; interleukins 2 and 10; nor TNF-β were observed by the jasminin stimuli. The supernatants, containing jasminin-induced-TNF-α, showed antiviral activity against HSV-1. The jasminin-stimulated cells caused the simultaneous activation of the Akt, MAPKs, and NF–κB signal pathways. Furthermore, the pretreatment of the cells with the Akt, MAPKs, and NF–κB inhibitors effectively suppressed jasminin-induced TNF-α production. Our research provides evidence that endogenous TNF-α can be used as a strategy to encounter viral infections. Additionally, the Akt, MAPKs, and NF–κB signaling pathways are involved in the TNF-α synthesis that induced by jasminin.  相似文献   

8.
Currently, conventional reductive catalytic methodologies do not guarantee general access to enantioenriched β-branched β-trifluoromethyl α-amino acid derivatives. Herein, a one-pot approach to these important α-amino acids, grounded on the reduction – ring opening of Erlenmeyer–Plöchl azlactones, is presented. The configurations of the two chirality centers of the products are established during each of the two catalytic steps, enabling a stereodivergent process.

A one-pot approach to β-branched β-trifluoromethyl α-amino acids, grounded on the reduction – ring opening of Erlenmeyer–Plöchl azlactones, and complementary to conventional catalytic asymmetric hydrogenation, is presented.  相似文献   

9.
10.
Articular cartilage (AC) damage is quite common, but due to AC’s poor self-healing ability, the damage can easily develop into osteoarthritis (OA). To solve this problem, we developed a microsphere/hydrogel system that provides two growth factors that promote cartilage repair: transforming growth factor-β3 (TGF-β3) to enhance cartilage tissue formation and ghrelin synergy TGF-β to significantly enhance the chondrogenic differentiation. The hydrogel and microspheres were characterized in vitro, and the biocompatibility of the system was verified. Double emulsion solvent extraction technology (w/o/w) is used to encapsulate TGF-β3 and ghrelin into microspheres, and these microspheres are encapsulated in a hydrogel to continuously release TGF-β3 and ghrelin. According to the chondrogenic differentiation ability of mesenchymal stem cells (MSCs) in vitro, the concentrations of the two growth factors were optimized to promote cartilage regeneration.  相似文献   

11.
Pulmonary fibrosis is a progressive and lethal lung disease characterized by the proliferation and differentiation of lung fibroblasts and the accumulation of extracellular matrices. Since pulmonary fibrosis was reported to be associated with adenosine monophosphate-activated protein kinase (AMPK) activation, which is negatively regulated by cereblon (CRBN), we aimed to determine whether CRBN is involved in the development of pulmonary fibrosis. Therefore, we evaluated the role of CRBN in bleomycin (BLM)-induced pulmonary fibrosis in mice and in transforming growth factor-beta 1 (TGF-β1)-induced differentiation of human lung fibroblasts. BLM-induced fibrosis and the mRNA expression of collagen and fibronectin were increased in the lung tissues of wild-type (WT) mice; however, they were significantly suppressed in Crbn knockout (KO) mice. While the concentrations of TGF-β1/2 in bronchoalveolar lavage fluid were increased via BLM treatment, they were similar between BLM-treated WT and Crbn KO mice. Knockdown of CRBN suppressed TGF-β1-induced activation of small mothers against decapentaplegic 3 (SMAD3), and overexpression of CRBN increased it. TGF-β1-induced activation of SMAD3 increased α-smooth muscle actin (α-SMA) and collagen levels. CRBN was found to be colocalized with AMPKα1 in lung fibroblasts. CRBN overexpression inactivated AMPKα1. When cells were treated with metformin (an AMPK activator), the CRBN-induced activation of SMAD3 and upregulation of α-SMA and collagen expression were significantly suppressed, suggesting that increased TGF-β1-induced activation of SMAD3 via CRBN overexpression is associated with AMPKα1 inactivation. Taken together, these data suggest that CRBN is a profibrotic regulator and maybe a potential target for treating lung fibrosis.Subject terms: Pathogenesis, Biochemistry  相似文献   

12.
Picosecond to millisecond laser time-resolved transient absorption spectroscopy was used to study molecular oxygen (O2) rebinding and conformational relaxation following O2 photodissociation in the α and β subunits within human hemoglobin in the quaternary R-like structure. Oxy-cyanomet valency hybrids, α2(Fe2+–O22(Fe3+–CN) and α2(Fe3+–CN)β2(Fe2+–O2), were used as models for oxygenated R-state hemoglobin. An extended kinetic model for geminate O2 rebinding in the ferrous hemoglobin subunits, ligand migration between the primary and secondary docking site(s), and nonexponential tertiary relaxation within the R quaternary structure, was introduced and discussed. Significant functional non-equivalence of the α and β subunits in both the geminate O2 rebinding and concomitant structural relaxation was revealed. For the β subunits, the rate constant for the geminate O2 rebinding to the unrelaxed tertiary structure and the tertiary transition rate were found to be greater than the corresponding values for the α subunits. The conformational relaxation following the O2 photodissociation in the α and β subunits was found to decrease the rate constant for the geminate O2 rebinding, this effect being more than one order of magnitude greater for the β subunits than for the α subunits. Evidence was provided for the modulation of the O2 rebinding to the individual α and β subunits within human hemoglobin in the R-state structure by the intrinsic heme reactivity through a change in proximal constraints upon the relaxation of the tertiary structure on a picosecond to microsecond time scale. Our results demonstrate that, for native R-state oxyhemoglobin, O2 rebinding properties and spectral changes following the O2 photodissociation can be adequately described as the sum of those for the α and β subunits within the valency hybrids. The isolated β chains (hemoglobin H) show similar behavior to the β subunits within the valency hybrids and can be used as a model for the β subunits within the R-state oxyhemoglobin. At the same time, the isolated α chains behave differently to the α subunits within the valency hybrids.

O2 rebinding and conformational relaxation following O2 photodissociation were studied on picosecond to millisecond time scale in the α and β subunits within human hemoglobin in the quaternary R-like structure.  相似文献   

13.
Pathogenic conversion of Th17 cells into multifunctional helper T cells or Th1 cells contributes to the pathogenesis of autoimmune diseases; however, the mechanism regulating the plasticity of Th17 cells remains unclear. Here, we found that Th17 cells expressed latent TGF-β1 in a manner dependent on autocrine TGF-β1. By employing IL-17-producing cell-specific Tgfb1 conditional knockout and fate-mapping systems, we demonstrated that TGF-β1-deficient Th17 cells are relatively susceptible to becoming IFN-γ producers through IL-12Rβ2 and IL-27Rα upregulation. TGF-β1-deficient Th17 cells exacerbated tissue inflammation compared to TGF-β1-sufficient Th17 cells in adoptive transfer models of experimental autoimmune encephalomyelitis and colitis. Thus, TGF-β1 production by Th17 cells provides an essential autocrine signal for maintaining the stability and regulating the pathogenicity of Th17 cells in vivo.Subject terms: Autoimmunity, Neuroimmunology  相似文献   

14.
Bone marrow mesenchymal stem cell (BMSC)-derived exosomes have been found to enhance fracture healing. In addition, microRNAs contributing to the healing of various bone fractures have attracted widespread attention in recent years, but knowledge of the mechanisms by which they act is still very limited. In this study, we clarified the function of altered microRNA-19b (miR-19b) expression in BMSCs in fracture healing. We modulated miR-19b expression via mimics/inhibitors in BMSCs and via agomirs in mice to explore the effects of these changes on osteogenic factors, bone cell mineralization and the healing status of modeled fractures. Through gain- and loss-of function assays, the binding affinity between miR-19b and WWP1/Smurf2 was identified and characterized to explain the underlying mechanism involving the KLF5/β-catenin signaling pathway. miR-19b promoted the differentiation of human BMSCs into osteoblasts by targeting WWP1 and Smurf2. Overexpression of WWP1 or Smurf2 degraded the target protein KLF5 in BMSCs through ubiquitination to inhibit fracture healing. KLF5 knockdown delayed fracture healing by modulating the Wnt/β-catenin signaling pathway. Furthermore, miR-19b enhanced fracture healing via the KLF5/β-catenin signaling pathway by targeting WWP1 or Smurf2. Moreover, miR-19b was found to be enriched in BMSC-derived exosomes, and treatment with exosomes promoted fracture healing in vivo. Collectively, these results indicate that mesenchymal stem cell-derived exosomal miR-19b represses the expression of WWP1 or Smurf2 and elevates KLF5 expression through the Wnt/β-catenin signaling pathway, thereby facilitating fracture healing.Subject terms: Diseases, Biotechnology  相似文献   

15.
Alzheimer’s disease (AD) is a severe neurodegenerative disorder. AD is pathologically characterized by the formation of intracellular neurofibrillary tangles, and extracellular amyloid plaques which were comprised of amyloid-beta (Aβ) peptides. Aβ induces neurodegeneration by activating microglia, which triggers neurotoxicity by releasing various inflammatory mediators and reactive oxygen species (ROS). Nuclear factor-kappa B (NF-κB) is expressed in human tissues including the brain and plays an important role in Aβ-mediated neuronal inflammation. Thus, the identification of molecules that inhibit the NF-κB pathway is considered an attractive strategy for the treatment and prevention of AD. Isoorientin (3′,4′,5,7-Tetrahydroxy-6-C-glucopyranosyl flavone; ISO), which can be extracted from several plant species, such as Philostachys and Patrinia is known to have various pharmacological activities such as anticancer, antioxidant, and antibacterial activity. However, the effect of ISO on Aβ-mediated inflammation and apoptosis in the brain has yet to be elucidated. In the present study, we investigated whether ISO regulated Aβ-induced neuroinflammation in microglial cells and further explored the underlying mechanisms. Our results showed that ISO inhibited the expression of iNOS and COX-2 induced by Aβ25–35. And, it inhibited the secretion of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In addition, ISO reduced the ROS production in Aβ25–35-induced BV2 cells and inhibited NF-κB activation. Furthermore, ISO blocked Aβ25–35-induced apoptosis of BV2 cells. Based on these findings, we suggest that ISO represents a promising therapeutic drug candidate for the treatment and prevention of AD.  相似文献   

16.
Drug targeting is a progressive area of research with folate receptor alpha (FRα) receiving significant attention as a biological marker in cancer drug delivery. The binding affinity of folic acid (FA) to the FRα active site provides a basis for recognition of FRα. In this study, FA was conjugated to beta-cyclodextrin (βCD) and subjected to in silico analysis (molecular docking and molecular dynamics (MD) simulation (100 ns)) to investigate the affinity and stability for the conjugated system compared to unconjugated and apo systems (ligand free). Docking studies revealed that the conjugated FA bound into the active site of FRα with a docking score (free binding energy < −15 kcal/mol), with a similar binding pose to that of unconjugated FA. Subsequent analyses from molecular dynamics (MD) simulations, root mean square deviation (RMSD), root mean square fluctuation (RMSF), and radius of gyration (Rg) demonstrated that FA and FA–βCDs created more dynamically stable systems with FRα than the apo-FRα system. All systems reached equilibrium with stable RMSD values ranging from 1.9–2.4 Å and the average residual fluctuation values of the FRα backbone atoms for all residues (except for terminal residues ARG8, THR9, THR214, and LEU215) were less than 2.1 Å with a consistent Rg value of around 16.8 Å throughout the MD simulation time (0–100 ns). The conjugation with βCD improved the stability and decreased the mobility of all the residues (except residues 149–151) compared to FA–FRα and apo-FRα systems. Further analysis of H-bonds, binding free energy (MM-PBSA), and per residue decomposition energy revealed that besides APS81, residues HIS20, TRP102, HIS135, TRP138, TRP140, and TRP171 were shown to have more favourable energy contributions in the holo systems than in the apo-FRα system, and these residues might have a direct role in increasing the stability of holo systems.  相似文献   

17.
How far can we push the limits in removing stereoelectronic protection from an unstable intermediate? We address this question by exploring the interplay between the primary and secondary stereoelectronic effects in the Baeyer–Villiger (BV) rearrangement by experimental and computational studies of γ-OR-substituted γ-peroxylactones, the previously elusive non-strained Criegee intermediates (CI). These new cyclic peroxides were synthesized by the peroxidation of γ-ketoesters followed by in situ cyclization using a BF3·Et2O/H2O2 system. Although the primary effect (alignment of the migrating C–Rm bond with the breaking O–O bond) is active in the 6-membered ring, weakening of the secondary effect (donation from the OR lone pair to the breaking C–Rm bond) provides sufficient kinetic stabilization to allow the formation and isolation of stable γ-hydroperoxy-γ-peroxylactones with a methyl-substituent in the C6-position. Furthermore, supplementary protection is also provided by reactant stabilization originating from two new stereoelectronic factors, both identified and quantified for the first time in the present work. First, an unexpected boat preference in the γ-hydroperoxy-γ-peroxylactones weakens the primary stereoelectronic effects and introduces a ∼2 kcal mol−1 Curtin–Hammett penalty for reacquiring the more reactive chair conformation. Second, activation of the secondary stereoelectronic effect in the TS comes with a ∼2–3 kcal mol−1 penalty for giving up the exo-anomeric stabilization in the 6-membered Criegee intermediate. Together, the three new stereoelectronic factors (inverse α-effect, misalignment of reacting bonds in the boat conformation, and the exo-anomeric effect) illustrate the richness of stereoelectronic patterns in peroxide chemistry and provide experimentally significant kinetic stabilization to this new class of bisperoxides. Furthermore, mild reduction of γ-hydroperoxy-γ-peroxylactone with Ph3P produced an isolable γ-hydroxy-γ-peroxylactone, the first example of a structurally unencumbered CI where neither the primary nor the secondary stereoelectronic effect are impeded. Although this compound is relatively unstable, it does not undergo the BV reaction and instead follows a new mode of reactivity for the CI – a ring-opening process.

Protecting stereoelectronic effects prevent Baeyer–Villiger rearrangement and stabilize γ-OX-γ-peroxylactones (X = H, OH), the previously elusive non-strained Criegee intermediates.  相似文献   

18.
Splenectomy has been reported to improve liver fibrosis in patients with cirrhosis and hypersplenism. However, the mechanisms remain unclear. Tumor necrosis factor superfamily 14 (TNFSF14; also known as LIGHT) is highly expressed in the context of fibrosis and promotes disease progression in patients with fibrotic diseases such as pulmonary and skin fibrosis. Here, we determined whether splenectomy controls the production of LIGHT to improve liver fibrosis. Splenectomy reduced serum LIGHT levels in cirrhotic patients with hypersplenism and a ConA-induced liver fibrosis mouse model. Blocking LIGHT resulted in the downregulation of TGF-β1 in RAW264.7 cells. LIGHT treatment of RAW264.7 and JS1 cells in coculture regulated transforming growth factor-β1 (TGF-β1) expression through the activation of JNK signaling. Small interfering RNA-mediated silencing of lymphotoxin β receptor (LTβR) in macrophages resulted in pronounced decreases in the levels of fibrosis and αSMA in JS1 cells. These results indicated that LIGHT bound to LTβR and drove liver fibrosis in vitro. Blocking TGF-β1 abolished the effect of LIGHT in vitro. Furthermore, the administration of recombinant murine LIGHT protein-induced liver fibrosis with splenectomy, while blocking LIGHT without splenectomy improved liver fibrosis in vivo, revealing that the decrease in fibrosis following splenectomy was directly related to reduced levels of LIGHT. Thus, high levels of LIGHT derived from the spleen and hepatic macrophages activate JNK signaling and lead to increased TGF-β1 production in hepatic macrophages. Splenectomy attenuates liver fibrosis by decreasing the expression of LIGHT.Subject terms: Tumour-necrosis factors, Liver fibrosis, Hepatic stellate cells, Liver cirrhosis, Experimental models of disease  相似文献   

19.
Soy diet is thought to help prevent cardiovascular diseases in humans. Isoflavone, which is abundant in soybean and other legumes, has been reported to possess antiplatelet activity and potential antithrombotic effect. Our study aims to elucidate the potential target of soy isoflavone in platelet. The anti-thrombosis formation effect of genistein and daidzein was evaluated in ex vivo perfusion chamber model under low (300 s−1) and high (1800 s−1) shear forces. The effect of genistein and daidzein on platelet aggregation and spreading was evaluated with platelets from both wildtype and GPIbα deficient mice. The interaction of these soy isoflavone with 14-3-3ζ was detected by surface plasmon resonance (SPR) and co-immunoprecipitation, and the effect of αIIbβ3-mediated outside-in signaling transduction was evaluated by western blot. We found both genistein and daidzein showed inhibitory effect on thrombosis formation in perfusion chamber, especially under high shear force (1800 s−1). These soy isoflavone interact with 14-3-3ζ and inhibited both GPIb-IX and αIIbβ3-mediated platelet aggregation, integrin-mediated platelet spreading and outside-in signaling transduction. Our findings indicate that 14-3-3ζ is a novel target of genistein and daidzein. 14-3-3ζ, an adaptor protein that regulates both GPIb-IX and αIIbβ3-mediated platelet activation is involved in soy isoflavone mediated platelet inhibition.  相似文献   

20.
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