RESUMO
As an age-related disease, intervertebral disc degeneration is closely related to inflammation and aging. Inflammatory cytokines and cellular senescence collectively contribute to the degradation of intervertebral disc. Blocking this synergy reduces disc extracellular matrix damage caused by inflammation and aging. In this study, drug-loaded nanofibers with sequential targeting functions are constructed through intelligent response, hydrophilicity, and in situ self-assembly empowerment of flurbiprofen. The peptide precursor responds to the cleavage of overexpressed MMP-2 in the degenerative intervertebral disc microenvironment (intracellular and extracellular), resulting in the formation of self-assembled nanofibers that enable the on-demand release of flurbiprofen and COX-2 response. In vitro, Comp. 1 (Flurbiprofen-GFFYPLGLAGEEEERGD) reduces the expression of inflammation-related genes and proteins and the polarization of M1 macrophages by competitively inhibiting COX-2 and increases the expression of extracellular matrix proteins COL-2 and aggrecan. Additionally, it can reduce the expression of Senescence-Associated Secretory Phenotype and DNA damage in aged nucleus pulposus cells and promote the recovery of proliferation and cell cycle. In vivo, drug-loaded nanofibers delay intervertebral disc degeneration by inhibiting inflammation and preventing the accumulation of senescent cells. Therefore, the sequentially targeted self-assembled drug-loaded nanofibers can delay intervertebral disc degeneration by blocking the synergistic effect of inflammatory cytokines and cellular senescence.
Assuntos
Degeneração do Disco Intervertebral , Nanofibras , Nanofibras/química , Degeneração do Disco Intervertebral/tratamento farmacológico , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/patologia , Animais , Ciclo-Oxigenase 2/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Senescência Celular/efeitos dos fármacos , Núcleo Pulposo/metabolismo , Núcleo Pulposo/efeitos dos fármacos , Núcleo Pulposo/patologia , Humanos , Camundongos , Proliferação de Células/efeitos dos fármacosRESUMO
Nanocatalytic medicine, which aims to accurately target and effectively treat tumors through intratumoral in situ catalytic reactions triggered by tumor-specific environments or markers, is an emerging technology. However, the relative lack of catalytic activity of nanoenzymes in the tumor microenvironment (TME) has hampered their use in biomedical applications. Therefore, it is crucial to develop a highly sensitive probe that specifically responds to the TME or disease markers in the TME for precision diagnosis and treatment of diseases. In this work, a chiral photoacoustic (PA) nanoprobe (D/L-Ce@MoO3) based on the H2O2-catalyzed TME activation reaction was constructed in a one-step method using D-cysteine (D-Cys) or L-cysteine (L-Cys), polymolybdate, and cerium nitrate as raw materials. The designed and synthesized D/L-Ce@MoO3 chiral nanoprobe can perform in situ, non-invasive, and precise imaging of pharmacological acute liver injury. In vivo and in vitro experiments have shown that the D/L-Ce@MoO3 probe had chiral properties, the CD signal decreased upon reaction with H2O2, and the absorption and PA signals increased with increasing H2O2 concentration. This is because of the catalytic reaction between Ce ions doped in the nanoenzyme and the high expression of H2O2 caused by drug-induced liver injury to produce ·OH, which has a strong oxidizing property to kill tumor cells and destroy the Mo-S bond in the probe, thus converting the chiral probe into an achiral polyoxometalate (POM) with PA signal.
Assuntos
Peróxido de Hidrogênio , Técnicas Fotoacústicas , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Técnicas Fotoacústicas/métodos , Animais , Camundongos , Humanos , Cério/química , Estereoisomerismo , Microambiente Tumoral , Cisteína/análise , Cisteína/química , Molibdênio/químicaRESUMO
The study aimed to investigate the alleviation of an ethanol-induced gastric ulcer in mice by apolysaccharide (PSP) from purple sweet potato (Ipomoea batatas (L.) Lam) and explore the mechanism. The anti-ulcer activity was determined by histopathological evaluation, total gastric acidity, pepsin activity, gastric ulcer index and gastric ulcer inhibition rate. The expression levels of inflammatory factors were detected using ELISA. A special protein meter was used to detect the content of immunoglobulin lgM, immunoglobulin lgG, and complements C3 and C4 in the serum of mice. The expression of CD4+/CD8+ lymphocyte subsets of mice was detected using flow cytometry. Western blot analysis was used to examine the effect of PSP on the PI3K/Akt/Rheb/mTOR pathway. The results showed that PSP could effectively reduce the total gastric acidity, pepsin activity, and the index and inhibition rate of gastric ulcers. At the same time, PSP could significantly increase the levels of immunoglobulins (lgG and lgM) and complements (C3 and C4). It could also increase the activity of peritoneal macrophages in mice and the expression of CD4+/CD8+ in the spleen. ELISA analysis showed that the contents of TNF-α, IL-1ß and IL-6 were significantly decreased and the content of IL-10 was significantly increased in the PSP group. The western blot analysis showed that PSP could upregulate the relative protein expressions of MUC5AC, PI3K, p-Akt, Rheb and mTOR. These results indicate that PSP can activate the PI3K/Akt/Rheb/mTOR signaling pathway to improve the immunity of mice and maintain the balance of the immune system, thereby protecting the gastric mucosa and improving stress gastric ulcers.
Assuntos
Ipomoea batatas , Polissacarídeos , Transdução de Sinais , Úlcera Gástrica , Animais , Humanos , Masculino , Camundongos , Antiulcerosos/farmacologia , Etanol , Ipomoea batatas/química , Fosfatidilinositol 3-Quinases/metabolismo , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Úlcera Gástrica/tratamento farmacológico , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/imunologia , Serina-Treonina Quinases TOR/metabolismoRESUMO
In order to further realize the resource reuse of walnut meal after oil extraction, walnut meal was used as raw material to prepare polypeptide, and its angiotensin-converting enzyme (ACE) inhibitory activity was investigated. The ACE inhibitory peptides were prepared from walnut meal protein by alkaline solution and acid precipitation. The hydrolysis degree and ACE inhibition rate were used as indexes to optimize the preparation process by single-factor experiment and response surface method. The components with the highest ACE activity were screened by ultrafiltration, and their antioxidant activities were evaluated in vitro. The effect of gastrointestinal digestion on the stability of walnut peptide was analyzed by measuring molecular weight and ACE inhibition rate. The results showed that the optimal extraction conditions were pH 9.10, hydrolysis temperature 54.50 °C, and hydrolysis time 136 min. The ACE inhibition rate of walnut meal hydrolysate (WMH) prepared under these conditions was 63.93% ± 0.43%. Under the above conditions, the fraction less than 3 kDa showed the highest ACE inhibitory activity among the ACE inhibitory peptides separated by ultrafiltration. The IC50 value of scavenging ·OH free radical was 1.156 mg/mL, the IC50 value of scavenging DPPH free radical was 0.25 mg/mL, and the IC50 value of scavenging O2- was 3.026 mg/mL, showing a strong total reducing ability. After simulated gastrointestinal digestion in vitro, the ACE inhibitory rate of walnut peptide decreased significantly, but it still maintained over 90% ACE inhibitory activity. This study provides a reference for the application of low-molecular-weight walnut peptide as a potential antioxidant and ACE inhibitor.
RESUMO
Bioactive peptides play a crucial role in the field of regenerative medicine and tissue engineering. However, their application in vivo and clinic is hindered by their poor stability, short half-life, and low retention rate. Herein, we propose a novel strategy for encapsulating bioactive peptides using giant macrocycles. Platelet-derived growth factor (PDGF) bioactive mimicking peptide Nap-FFGVRKKP (P) was selected as the representative of a bioactive peptide. Quaterphen[4]arene (4) exhibited extensive host-guest complexation with P, and the binding constant was (1.16 ± 0.10) × 107 M-1. In vitro cell experiments confirmed that P + 4 could promote the proliferation of BMSCs by 2.27 times. Even with the addition of the inhibitor dexamethasone (Dex), P + 4 was still able to save 76.94% of the cells in the control group. Compared to the Dex group, the bone mass of the mice with osteoporosis in the P + 4 group was significantly increased. The mean trabecular thickness (Tb.Th) increased by 17.03%, and the trabecular bone volume fraction (BV/TV) values increased by 40.55%. This supramolecular bioactive peptide delivery strategy provides a general approach for delivering bioactive peptides and opens up new opportunities for the development of peptide-based drugs.
Assuntos
Dexametasona , Glucocorticoides , Células-Tronco Mesenquimais , Osteoporose , Peptídeos , Animais , Osteoporose/tratamento farmacológico , Glucocorticoides/administração & dosagem , Glucocorticoides/farmacologia , Glucocorticoides/química , Dexametasona/administração & dosagem , Dexametasona/química , Peptídeos/química , Peptídeos/administração & dosagem , Peptídeos/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Camundongos , Compostos Macrocíclicos/química , Compostos Macrocíclicos/administração & dosagem , Compostos Macrocíclicos/farmacologia , Camundongos Endogâmicos C57BL , Feminino , Células Cultivadas , MasculinoRESUMO
Natural product libraries with a remarkable range of biological activities play pivotal roles in drug discoveries due to their extraordinary structural complexity and immense diversity. l-Kynurenine (l-Kyn)-based derivatives are privileged pharmacophores that exhibit diverse therapeutic implications in neurological disorders. However, the difficulty in obtaining l-Kyn analogues with different skeletal structures has recently led to a decline in its medicinal research. Herein, we report a two-step, one-pot protocol for diversity-oriented biosynthesis of a collection of previously intractable l-Kyn-like compounds. The success of these challenging transformations mainly depends on unlocking the new catalytic scope of tryptophan 2,3-dioxygenases, followed by rational site-directed mutagenesis to modify the substrate domains further. As a result, 18 kynurenine analogues with diverse molecular scaffolds can be rapidly assembled in a predictable manner with 20-83% isolated yields, which not only fill the voids of the catalytic profile of tryptophan 2,3-dioxygenases with an array of substituent groups (e.g., F, Cl, Br, I, CH3, OCH3, and NO2) but also update the current understanding of its substrate spectrum. Our work highlights the great potential of existing enzymes in addressing long-standing synthetic challenges for facilitating the development or discovery of new drug candidates. Furthermore, our approach enables translating the reaction parameters from Eppendorf tubes to 1 L scale, affording l-4-Cl-Kyn and l-5-Cl-Kyn both on a gram scale with more than 80% isolated yields, and provides a promising alternative to further industrial applications.