RESUMO
Blood-brain barrier (BBB) disruption is a major pathophysiological event of ischemic stroke. Brain microvascular endothelial cells are critical to maintain homeostasis between central nervous system and periphery. Resveratrol protects against ischemic stroke. 3,3',4,5'-tetramethoxy-trans-stilbene (3,3',4,5'-TMS) and 3,4',5-trimethoxy-trans-stilbene (3,4',5-TMS) are resveratrol derivatives with addition of methoxy groups, showing better pharmacokinetic performance. We aimed to explore their protective effects and underlying mechanisms. Oxygen-glucose deprivation (OGD) model was applied in bEnd.3 cell line, mouse brain microvascular endothelium to mimic ischemia. The cells were pre-treated with 3,3',4,5'-TMS or 3,4',5-TMS (1 and 5 µM, 24 h) and then subjected to 2-h OGD injury. Cell viability, levels of proinflammatory cytokines and reactive oxygen species (ROS), and protein expressions were measured by molecular assays and fluorescence staining. OGD injury triggered cell death, inflammatory responses, ROS production and nuclear factor-kappa B (NF-κB) signalling pathway. These impairments were remarkably attenuated by the two stilbenes, 3,3',4,5'-TMS and 3,4',5-TMS. They also alleviated endothelial barrier injuries through upregulating the expression of tight junction proteins. Moreover, 3,3',4,5'-TMS and 3,4',5-TMS activated 5' adenosine monophosphate-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS). Overall, 3,3',4,5'-TMS and 3,4',5-TMS exert protective effects against OGD damage through suppressing cell death, inflammatory responses, oxidative stress, as well as BBB disruption on bEnd.3 cells.
Assuntos
Encéfalo , Sobrevivência Celular , Células Endoteliais , Glucose , Oxigênio , Espécies Reativas de Oxigênio , Estilbenos , Estilbenos/farmacologia , Animais , Glucose/metabolismo , Camundongos , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Oxigênio/metabolismo , Linhagem Celular , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Sobrevivência Celular/efeitos dos fármacos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Citocinas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacosRESUMO
The design and development of advanced drug delivery systems targeting reactive oxygen species (ROS) have gained significant interest in recent years for treating various diseases, including cancer, psychiatric diseases, cardiovascular diseases, neurological diseases, metabolic diseases, and chronic inflammations. Integrating specific chemical bonds capable of effectively responding to ROS and triggering drug release into the delivery system is crucial. In this Review, we discuss commonly used conjugation linkers (chemical bonds) and categorize them into two groups: cleavable linkers and noncleavable linkers. Our goal is to clarify their unique drug release mechanisms from a chemical perspective and provide practical organic synthesis approaches for their efficient production. We showcase numerous significant examples to demonstrate their synthesis routes and diverse applications. Ultimately, we strive to present a comprehensive overview of cleavage and noncleavage chemistry, offering insights into the development of smart drug delivery systems that respond to ROS.
Assuntos
Nanopartículas , Neoplasias , Humanos , Espécies Reativas de Oxigênio/metabolismo , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Inflamação/tratamento farmacológico , Nanopartículas/química , Liberação Controlada de FármacosRESUMO
Incorporating temperature- and air-stable organic radical species into molecular designs is a potentially advantageous means of controlling the properties of electronic materials. However, we still lack a complete understanding of the structure-property relationships of organic radical species at the molecular level. In this work, the charge transport properties of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) radical-containing nonconjugated molecules are studied using single-molecule charge transport experiments and molecular modeling. Importantly, the TEMPO pendant groups promote temperature-independent molecular charge transport in the tunneling region relative to the quenched and closed-shell phenyl pendant groups. Results from molecular modeling show that the TEMPO radicals interact with the gold metal electrodes near the interface to facilitate a high-conductance conformation. Overall, the large enhancement of charge transport by incorporation of open-shell species into a single nonconjugated molecular component opens exciting avenues for implementing molecular engineering in the development of next-generation electronic devices based on novel nonconjugated radical materials.
RESUMO
The transient self-assembly of molecules under the direction of a consumable fuel source is fundamental to biological processes such as cellular organization and motility. Such biomolecular assemblies exist in an out-of-equilibrium state, requiring continuous consumption of high energy molecules. At the same time, the creation of bioinspired supramolecular hydrogels has traditionally focused on associations occurring at the thermodynamic equilibrium state. Here, hydrogels are prepared from cucurbit[7]uril host-guest supramolecular interactions through transient physical crosslinking driven by the consumption of a reactive chemical fuel. Upon action from this fuel, the affinity and dynamics of CB[7]-guest recognition are altered. In this way, the lifetime of transient hydrogel formation and the dynamic modulus obtained are governed by fuel consumption, rather than being directed by equilibrium complex formation.
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Immunotherapy sheds new light to cancer treatment and is satisfied by cancer patients. However, immunotoxicity, single-source antibodies, and single-targeting stratege are potential challenges to the success of cancer immunotherapy. A huge number of promising lead compounds for cancer treatment are of natural origin from herbal medicines. The application of natural products from herbal medicines that have immunomodulatory properties could alter the landscape of immunotherapy drastically. The present study summarizes current medication for cancer immunotherapy and discusses the potential chemicals from herbal medicines as immune checkpoint inhibitors that have a broad range of immunomodulatory effects. Therefore, this review provides valuable insights into the efficacy and mechanism of actions of cancer immunotherapies, including natural products and combined treatment with immune checkpoint inhibitors, which could confer an improved clinical outcome for cancer treatment.
Assuntos
Produtos Biológicos , Neoplasias , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Humanos , Inibidores de Checkpoint Imunológico , Imunomodulação , Imunoterapia , Neoplasias/terapiaRESUMO
Aeromonas hydrophila (A. hydrophila) is an opportunistic pathogen of fish-human-livestock, which poses a threat to the development of aquaculture. Lytic phage has long been considered as an effective bactericidal agent. However, the rapid development of phage resistance seriously hinders the continuous application of lytic phages. In our study, a new bacteriophage vB_ AhaP_PZL-Ah8 was isolated from sewage and its characteristics and genome were investigated. Phage vB_ AhaP_PZL-Ah8 has been classified as the member of the Podoviridae family, which exhibited the latent period was about 30 min. As revealed from the genomic sequence analysis, vB_ AhaP_PZL-Ah8 covered a double-stranded genome of 40,855 bp (exhibiting 51.89% G + C content), with encoding 52 predicted open reading frames (ORFs). The results suggested that the combination of vB_ AhaP_PZL-Ah8 and another A. hydrophila phage vB_ AhaP_PZL-Ah1 could improve the therapeutic efficacy both in vitro and in vivo. The resistance mutation frequency of A. hydrophila cells infected with the mixture phage (vB_ AhaP_PZL-Ah8+ vB_ AhaP_PZL-Ah1) was significantly lower than cells treated with single phage (P <0.01). Phage therapy in vivo showed that the survival rate in the mixture phage treatment group was significantly higher than that in single phage treatment group.
Assuntos
Bacteriófagos , Aeromonas hydrophila , Animais , Aquicultura , Bacteriófagos/genética , Genoma Viral , Humanos , Fases de Leitura AbertaRESUMO
Inflammatory bowel disease (IBD) refers to a gamut of disorders that are characterized by chronic intestinal inflammation, including ulcerative colitis (UC) and Crohn's disease (CD), which often leads to mucosal ulceration and progressive loss of intestinal function. The etiopathogenesis of IBD has not been completely clarified, although multiple factors involving genetic modifications, host immune dysfunction, intestinal dysbiosis and environmental effects have been implicated. Currently, pharmacotherapies including both non-targeted and targeted biological agents are widely used for the clinical treatment of IBD. In addition, novel therapeutic approaches that target the intestinal microorganisms, such as fecal microbiota transplantation, antibiotics, probiotics and microbial metabolite inhibitors, are also under development. However, these treatments are either accompanied by side effects or cannot achieve complete clinical remission when used alone. The efficacy and safety of drugs are currently a clinical challenge. Thus, advanced drug delivery systems are needed for targeted delivery of drugs to the inflammatory sites and avoid absorption by healthy tissues. In this review, we have summarized the latest research on the pathogenesis of IBD and the emerging pharmacotherapies, and discussed potential therapeutic targets for innovative therapies.
Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Colite Ulcerativa/complicações , Doença de Crohn/complicações , Disbiose/complicações , Transplante de Microbiota Fecal , Humanos , Inflamação/complicações , Doenças Inflamatórias Intestinais/tratamento farmacológicoRESUMO
Aeromonas hydrophila (A. hydrophila) is an opportunistic pathogen of fish, humans, and livestock, and has a severe negative impact on aquaculture development. Phage therapy is considered an alternative strategy for controlling bacterial infections and contamination. In this study, we isolated and characterized the genomes of two A. hydrophila-specific phages, PZL-Ah1 and PZL-Ah8, which, based on transmission electron microscopy, were identified as members of the family Podoviridae. Both of these phages had a relatively narrow host range, with lytic activity against Aeromonas spp. strains. Whole-genome sequence analysis revealed that PZL-Ah1 and PZL-Ah8 have a double-stranded DNA genome of 38,641 bp and 40,855 bp in length, with a GC content of 53.68% and 51.89%, respectively. Forty-four open reading frames (ORFs) were predicted in PZL-Ah1, and 52 were predicted in PZL-Ah8. Twenty-eight (63.6%) ORFs in PZL-Ah1 and 29 (55.8%) ORFs in PZL-Ah8 were predicted to encode functional proteins with homologs in the NCBI database, while the remaining ORFs were classified as encoding hypothetical proteins with unknown functions. A comparison with known phage genes suggested that ORF 02, ORF 29, and ORF 04 of PZL-Ah1 and ORF 2 and ORF 4 of PZL-Ah8 are involved in host cell lysis. This study expands the phage genome database and provides good candidates for phage typing applications.
Assuntos
Bacteriófagos , Podoviridae , Aeromonas hydrophila/genética , Animais , Bacteriófagos/genética , DNA Viral/genética , Genoma Viral , Humanos , Fases de Leitura Aberta , FilogeniaRESUMO
Aeromonas veronii (A. veronii) is an opportunistic pathogen of fish-human-livestock, which poses a threat to the development of aquaculture. Based on our previous studies on proteomics and genomics, we found out that the aodp gene may be related to the virulence of A. veronii TH0426. However, aodp gene encodes a hypothetical protein with an unknown function, and its role in A. veronii TH0426 is not clear. Here, we first constructed a mutant strain (â³-aodp) to investigate the functional role of aodp in A. veronii TH0426. Compared with the wild strain A. veronii TH0426, the growth rate of strain â³-aodp was slower and was resistant to neomycin and kanamycin, but sensitive to cephalexin. The swimming and swarming ability of â³-aodp strain decreased, and the pathogenicity to mice decreased by 15.84-fold. Besides, the activity of caspase-3 in EPCs infected with â³-aodp strain was 1.49-fold lower than that of the wild strain. We examined 20 factors closely related to A. veronii virulence, among them 17 genes were down-regulated as a result of aodp deficiency. This study laid a foundation for further studies on the pathogenesis of A. veronii.
Assuntos
Aeromonas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Doenças dos Roedores , Aeromonas/genética , Aeromonas veronii/genética , Animais , Infecções por Bactérias Gram-Negativas/veterinária , Camundongos , Virulência , Fatores de Virulência/genética , Peixe-ZebraRESUMO
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, which is characterized by hyperglycemia, chronic insulin resistance, progressive decline in ß-cell function, and defect in insulin secretion. It has become one of the leading causes of death worldwide. At present, there is no cure for T2DM, but it can be treated, and blood glucose levels can be controlled. It has been reported that diabetic patients may suffer from the adverse effects of conventional medicine. Therefore, alternative therapy, such as traditional Chinese medicine (TCM), can be used to manage and treat diabetes. In this review, glycyrrhizic acid (GL) and its derivatives are suggested to be promising candidates for the treatment of T2DM and its complications. It is the principal bioactive constituent in licorice, one type of TCM. This review comprehensively summarized the therapeutic effects and related mechanisms of GL and its derivatives in managing blood glucose levels and treating T2DM and its complications. In addition, it also discusses existing clinical trials and highlights the research gap in clinical research. In summary, this review can provide a further understanding of GL and its derivatives in T2DM as well as its complications and recent progress in the development of potential drugs targeting T2DM.
Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Ácido Glicirrízico/farmacologia , Ácido Glicirrízico/uso terapêutico , Humanos , Hipoglicemiantes/uso terapêutico , Secreção de InsulinaRESUMO
Jatrorrhizine (JAT) is one of the major bioactive protoberberine alkaloids found in rhizoma coptidis, which has hypoglycemic and hypolipidemic potential. This study aimed to evaluate the vasoprotective effects of JAT in diabetes and obesity and the underlying mechanism involved. Mouse aortas, carotid arteries and human umbilical cord vein endothelial cells (HUVECs) were treated with risk factors (high glucose or tunicamycin) with and without JAT ex vivo and in vitro. Furthermore, aortas were obtained from mice with chronic treatment: (1) control; (2) diet-induced obese (DIO) mice fed a high-fat diet (45% kcal% fat) for 15 weeks; and (3) DIO mice orally administered JAT at 50 mg/kg/day for the last 5 weeks. High glucose or endoplasmic reticulum (ER) stress inducer tunicamycin impaired acetylcholine-induced endothelium-dependent relaxations (EDRs) in mouse aortas, induced oxidative stress in carotid arteries and HUVECs, downregulated phosphorylations of Akt at Ser473 and eNOS at Ser1177 and enhanced ER stress in mouse aortas and HUVECs, and these impairments were reversed by cotreatment with JAT. JAT increased NO release in high-glucose-treated mouse aortas and HUVECs. In addition, chronic JAT treatment restored endothelial function with EDRs comparable to the control, increased Akt/eNOS phosphorylation, and attenuated ER stress and oxidative stress in aortas from DIO mice. Blood pressure, glucose sensitivity, fatty liver and its morphological change, as well as plasma levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and plasma lipid profile, were also normalized by JAT treatment. Collectively, our data may be the first to reveal the vasoprotective effect of JAT that ameliorates endothelial dysfunction in diabetes and obesity through enhancement of the Akt/eNOS pathway and NO bioavailability, as well as suppression of ER stress and oxidative stress.
Assuntos
Diabetes Mellitus , Medicamentos de Ervas Chinesas , Camundongos , Humanos , Animais , Estresse do Retículo Endoplasmático , Tunicamicina/farmacologia , Endotélio Vascular/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Acetilcolina/metabolismo , Alanina Transaminase/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Camundongos Endogâmicos C57BL , Diabetes Mellitus/metabolismo , Estresse Oxidativo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Obesidade/metabolismo , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Aspartato Aminotransferases/metabolismo , Lipídeos/farmacologiaRESUMO
Coptisine is the major bioactive protoberberine alkaloid found in Rhizoma Coptidis. Coptisine reduces inflammatory responses and improves glucose tolerance; nevertheless, whether coptisine has vasoprotective effect in diabetes is not fully characterized. Conduit arteries including aortas and carotid arteries were obtained from male C57BL/6J mice for ex vivo treatment with risk factors (high glucose or tunicamycin) and coptisine. Some arterial rings were obtained from diabetic mice, which were induced by high-fat diet (45% kcal% fat) feeding for 6 weeks combined with a low-dose intraperitoneal injection of streptozotocin (120 mg/kg). Functional studies showed that coptisine protected endothelium-dependent relaxation in aortas against risk factors and from diabetic mice. Coptisine increased phosphorylations of AMPK and eNOS and downregulated the endoplasmic reticulum (ER) stress markers as determined by Western blotting. Coptisine elevates NO bioavailability and decreases reactive oxygen species level. The results indicate that coptisine improves vascular function in diabetes through suppression of ER stress and oxidative stress, implying the therapeutic potential of coptisine to treat diabetic vasculopathy.
Assuntos
Berberina/análogos & derivados , Diabetes Mellitus Experimental/complicações , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Doenças Vasculares/tratamento farmacológico , Doenças Vasculares/etiologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Aorta/efeitos dos fármacos , Aorta/metabolismo , Berberina/farmacologia , Diabetes Mellitus Experimental/metabolismo , Dieta Hiperlipídica/efeitos adversos , Endotélio Vascular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Doenças Vasculares/metabolismoRESUMO
To identify the chemical components responsible for the anti-hyperglycemic effect of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae) leaves, an ethanol extract (CPE) and a water extract (CPW) of C. paliurus leaves, as well as their total flavonoids (CPF), triterpenoids (CPT) and crude polysaccharides (CPP), were prepared and assessed on streptozotocin (STZ)-induced diabetic mice. After being orally administrated once a day for 24 days, CPF (300 mg/kg), CPP (180 mg/kg), or CPF+CPP (300 mg/kg CPF + 180 mg/kg CPP) treatment reversed STZ-induced body weight and muscle mass losses. The glucose tolerance tests and insulin tolerance tests suggested that CPF, CPP, and CPF+CPP showed anti-hyperglycemic effect in STZ-induced diabetic mice. Furthermore, CPF enhances glucose-stimulated insulin secretion in MIN6 cells and insulin-stimulated glucose uptake in C2C12 myotubes. CPF and CPP suppressed inflammatory cytokine levels in STZ-induced diabetic mice. Additionally, CPF and CPP improved STZ-induced diabetic nephropathy assessed by H&E staining, blood urea nitrogen content, and urine creatinine level. The molecular networking and Emperor analysis results indicated that CPF showed potential anti-hyperglycemic effects, and HPLC-MS/MS analysis indicated that CPF contains 3 phenolic acids and 9 flavonoids. In contrast, CPT (650 mg/kg) and CPC (300 mg/kg CPF + 180 mg/kg CPP + 650 mg/kg CPT) did not show anti-hyperglycemic effect. Taken together, polysaccharides and flavonoids are responsible for the anti-hyperglycemic effect of C. paliurus leaves, and the clinical application of C. paliurus need to be refined.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Juglandaceae/química , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Animais , Linhagem Celular , Hipoglicemiantes/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/química , EstreptozocinaRESUMO
Pseudomonas aeruginosa is a gram-negative bacterium associated with serious illnesses, including ventilator-associated pneumonia and various sepsis syndromes in humans. Understanding the host immune mechanisms against P. aeruginosa is, therefore, of clinical importance. The present study identified serum amyloid A3 (SAA3) as being highly inducible in mouse bronchial epithelium following P. aeruginosa infection. Genetic deletion of Saa3 rendered mice more susceptible to P. aeruginosa infection with decreased neutrophil superoxide anion production, and ex vivo treatment of mouse neutrophils with recombinant SAA3 restored the ability of neutrophils to produce superoxide anions. The SAA3-deficient mice showed exacerbated inflammatory responses, which was characterized by pronounced neutrophil infiltration, elevated expression of TNF-α, KC/CXCL1, and MIP-2/CXCL2 in bronchoalveolar lavage fluid (BALF), and increased lung microvascular permeability compared with their wild-type littermates. BALF neutrophils from Saa3 knockout mice exhibited reduced superoxide anion production compared with neutrophils from wild-type mice. Adoptive transfer of SAA3-treated neutrophils to Saa3 knockout mice ameliorated P. aeruginosa-induced acute lung injury. These findings demonstrate that SAA3 not only serves as a biomarker for infection and inflammation, but also plays a protective role against P. aeruginosa infection-induced lung injury in part through augmentation of neutrophil bactericidal functions.
Assuntos
Lesão Pulmonar Aguda/microbiologia , Lesão Pulmonar Aguda/prevenção & controle , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/fisiologia , Proteína Amiloide A Sérica/metabolismo , Animais , Quimiocinas/metabolismo , Epitélio/patologia , Pulmão/irrigação sanguínea , Pulmão/microbiologia , Pulmão/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microvasos/patologia , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Pneumonia/complicações , Pneumonia/microbiologia , Pneumonia/patologia , Proteína Amiloide A Sérica/deficiênciaRESUMO
Reactive oxygen species (ROS) are chemically reactive species that are produced in cellular aerobic metabolism. They mainly include superoxide anion, hydrogen peroxide, hydroxyl radicals, singlet oxygen, ozone, and nitric oxide and are implicated in many physiological and pathological processes. Bilirubin, a cardinal pigment in the bile, has been increasingly investigated to treat cancer, diabetes, ischemia-reperfusion injury, asthma, and inflammatory bowel diseases (IBD). Indeed, bilirubin has been shown to eliminate ROS production, so it is now considered as a promising therapeutic agent for ROS-mediated diseases and can be used for the development of antioxidative nanomedicines. This review summarizes the current knowledge of the physiological mechanisms of ROS production and its role in pathological changes and focuses on discussing the antioxidative effects of bilirubin and its application in the experimental studies of nanomedicines. Previous studies have shown that bilirubin was mainly used as a responsive molecule in the microenvironment of ROS overproduction in neoplastic tissues for the development of anticancer nanodrugs; however, it could also exert powerful ROS scavenging activity in chronic inflammation and ischemia-reperfusion injury. Therefore, bilirubin, as an inartificial ROS scavenger, is expected to be used for the development of nanomedicines against more diseases due to the universality of ROS involvement in human pathological conditions.
Assuntos
Antioxidantes/farmacologia , Bilirrubina/farmacologia , Nanomedicina/métodos , Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Antioxidantes/efeitos adversos , Antioxidantes/uso terapêutico , Bilirrubina/efeitos adversos , Bilirrubina/uso terapêutico , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Camundongos , Neoplasias/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Resultado do Tratamento , Microambiente Tumoral/efeitos dos fármacosRESUMO
During the past decade, developments in computational processing and X-ray crystallography have allowed virtual screening become integrated into drug discovery campaigns. This review focuses on the recent advancements in the drug discovery of VEGFR2 tyrosine kinase inhibitors (VEGFR2 TKIs) by using in silico methodologies. An introduction for the methodology framework of pharmacophore modeling, molecular docking and structure-based design are provided. We discuss the recent studies on the structures of VEGFR2 protein kinase in different binding modes, and the insights on molecular interactions gained from knowledge of the co-crystal structures complex with structurally diverse VEGFR2 inhibitors. We provide some aspects of model construction and molecular docking techniques. Several representative examples of successful applications on VEGFR2 virtual screening for hit discovery, lead optimization and structure-based design are also presented.
Assuntos
Simulação de Acoplamento Molecular/métodos , Inibidores de Proteínas Quinases/química , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/químicaRESUMO
The underlying mechanisms of itch are poorly understood. We have investigated a model involving the chemoattractant leukotriene B4 (LTB4) that is up-regulated in common skin diseases. Intradermal injection of LTB4 (0.1 nmol/site) into female CD1 mice induced significant scratching movements (used as an itch index) compared with vehicle-injected (0.1% bovine serum albumin-saline) mice. Intraperitoneal transient receptor potential (TRP) channel antagonist treatment significantly inhibited itch as follows: TRP vanilloid 1 (TRPV1) antagonist SB366791 (0.5 mg/kg, by 97%) and the TRP ankyrin 1 (TRPA1) antagonists TCS 5861528 (10 mg/kg; 82%) and HC-030031 (100 mg/kg; 76%). Leukotriene B4 receptor 2 antagonism by LY255283 (5 mg/kg i.p.; 62%) reduced itch. Neither TRPV1-knockout (TRPV1-KO) nor TRPA1-knockout (TRPA1-KO mice exhibited LTB4-induced itch compared with their wild-type counterparts. The reactive oxygen species scavengers N-acetylcysteine (NAC; 204 mg/kg i.p.; 86%) or superoxide dismutase (SOD; 10 mg/kg i.p.; 83%) also inhibited itch. LTB4-induced superoxide release was attenuated by TCS 5861528 (56%) and HC-030031 (66%), NAC (58%), SOD (50%), and LY255283 (59%) but not by the leukotriene B4 receptor 1 antagonist U-75302 (9 nmol/site) or SB366791. Itch, superoxide, and myeloperoxidase generation were inhibited by the leukocyte migration inhibitor fucoidan (10 mg/kg i.v.) by 80, 61, and 34%, respectively. Myeloperoxidase activity was also reduced by SB366791 (35%) and SOD (28%). TRPV1-KO mice showed impaired myeloperoxidase release, whereas TRPA1-KO mice exhibited diminished production of superoxide. This result provides novel evidence that TRPA1 and TRPV1 contribute to itch via distinct mechanisms.
Assuntos
Leucócitos/metabolismo , Leucotrieno B4/farmacologia , Superóxidos/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Animais , Anquirinas/farmacologia , Feminino , Leucócitos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Prurido/tratamento farmacológico , Prurido/metabolismo , Receptores do Leucotrieno B4/antagonistas & inibidores , Canais de Cátion TRPV/metabolismoRESUMO
The formation of transient structures plays important roles in biological processes, capturing temporary states of matter through influx of energy or biological reaction networks catalyzed by enzymes. These natural transient structures inspire efforts to mimic this elegant mechanism of structural control in synthetic analogues. Specifically, though traditional supramolecular materials are designed on the basis of equilibrium formation, recent efforts have explored out-of-equilibrium control of these materials using both direct and indirect mechanisms; the preponderance of such works has been in the area of low molecular weight gelators. Here, a transient supramolecular hydrogel is realized through cucurbit[7]uril host-guest physical crosslinking under indirect control from a biocatalyzed network that regulates and oscillates pH. The duration of transient hydrogel formation, and resulting mechanical properties, are tunable according to the dose of enzyme, substrate, or pH stimulus. This tunability enables control over emergent functions, such as the programmable burst release of encapsulated model macromolecular payloads.
Assuntos
Hidrocarbonetos Aromáticos com Pontes , Hidrogéis , Imidazóis , Hidrogéis/química , Hidrogéis/síntese química , Concentração de Íons de Hidrogênio , Imidazóis/química , Hidrocarbonetos Aromáticos com Pontes/química , Substâncias Macromoleculares/química , Substâncias Macromoleculares/síntese química , Biocatálise , Estrutura Molecular , Muramidase/química , Muramidase/metabolismoRESUMO
BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a rare and serious systemic inflammatory disorder that occurs following a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aims to investigate the clinical manifestations, risk factors associated with pediatric intensive care unit (PICU) admission, and outcome among children with MIS-C in Taiwan. METHODS: A retrospective analysis was conducted among pediatric patients diagnosed with MIS-C between June 2022 and February 2023 at Chang Gung Memorial Hospital, Linkou, Taiwan. Data on demographics, clinical features, laboratory findings, treatment modalities, and outcomes were collected and analyzed. RESULTS: Twenty-eight MIS-C patients, including 9 boys and 19 girls, with an average age of 5.3 ± 3.8 years old, were enrolled. Most of the cases (78.6%) were diagnosed following the first pandemic wave of COVID-19 in Taiwan. The leading clinical manifestations observed were fever (100%), skin rash (64.3%), tachycardia (46.4%), and vomiting (46.4%). Nine patients (32.1%) were admitted to the PICU due to hypotension or neurological manifestations. Higher levels of band-form white blood cells, procalcitonin, ferritin, d-dimer, prothrombin time, NT-proBNP, and lower platelet levels on arrival were associated with PICU admission (p = 3.9 × 10-2 ,9 × 10-3 , 4 × 10-3 ,1 × 10-3 , 5 × 10-3 , 4.1 × 10-2 , and 3.4 × 10-2 , respectively). Arrhythmia in one case (3.5%) and coronary artery abnormalities, including dilatation in two cases (7.1%) and small aneurysms in one case (3.5%) were identified. Regardless of ICU admission, no patients experienced systolic dysfunction or mortality following treatment. CONCLUSION: MIS-C cases in Taiwan have a favorable outcome. Although one-third of the patients required PICU admission, none of the MIS-C cases resulted in severe cardiovascular morbidity or mortality. This study provides valuable insights into the clinical manifestations and outcomes associated with PICU admission in children with MIS-C in Taiwan.
Assuntos
COVID-19/complicações , Doenças do Tecido Conjuntivo , Síndrome de Resposta Inflamatória Sistêmica , Masculino , Feminino , Humanos , Criança , Lactente , Pré-Escolar , Estudos Retrospectivos , Taiwan/epidemiologia , Hospitalização , SARS-CoV-2RESUMO
Hyperglycemia induces chronic stresses, such as oxidative stress and endoplasmic reticulum (ER) stress, which can result in [Formula: see text]-cell dysfunction and development of Type 2 Diabetes Mellitus (T2DM). Ginsenoside Rk1 is a minor ginsenoside isolated from Ginseng. It has been shown to exert anti-cancer, anti-inflammatory, anti-oxidant, and neuroprotective effects; however, its effects on pancreatic cells in T2DM have never been studied. This study aims to examine the novel effects of Ginsenoside Rk1 on ER stress-induced apoptosis in a pancreatic [Formula: see text]-cell line MIN6 and HFD-induced diabetic pancreas, and their underlying mechanisms. We demonstrated that Ginsenoside Rk1 alleviated ER stress-induced apoptosis in MIN6 cells, which was accomplished by directly targeting and activating insulin-like growth factor 1 receptor (IGF-1R), thus activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/Bcl-2-associated agonist of cell death (Bad)-B-cell lymphoma-2 (Bcl-2) pathway. This pathway was also confirmed in an HFD-induced diabetic pancreas. Meanwhile, the use of the IGF-1R inhibitor PQ401 abolished this anti-apoptotic effect, confirming the role of IGF-1R in mediating anti-apoptosis effects exerted by Ginsenoside Rk1. Besides, Ginsenoside Rk1 reduced pancreas weights and increased pancreatic insulin contents, suggesting that it could protect the pancreas from HFD-induced diabetes. Taken together, our study provided novel protective effects of Ginsenoside Rk1 on ER stress-induced [Formula: see text]-cell apoptosis and HFD-induced diabetic pancreases, as well as its direct target with IGF-1R, indicating that Ginsenoside Rk1 could be a potential drug for the treatment of T2DM.