RESUMO
Autophagy mediates PM2.5-related lung injury (LI) and is tightly linked to inflammation and apoptosis processes. IL-37 has been demonstrated to regulate autophagy. This research aimed to examine the involvement of IL-37 in the progression of PM2.5-related LI and assess whether autophagy serves as a mediator for its effects.To create a model of PM2.5-related LI, this research employed a nose-only PM2.5 exposure system and utilized both human IL-37 transgenic mice and wild-type mice. The hIL-37tg mice demonstrated remarkable reductions in pulmonary inflammation and pathological LI compared to the WT mice. Additionally, they exhibited activation of the AKT/mTOR signaling pathway, which served to regulate the levels of autophagy and apoptosis.Furthermore, in vitro experiments revealed a dose-dependent upregulation of autophagy and apoptotic proteins following exposure to PM2.5 DMSO extraction. Simultaneously, p-AKT and p-mTOR expression was found to decrease. However, pretreatment with IL-37 demonstrated a remarkable reduction in the levels of autophagy and apoptotic proteins, along with an elevation of p-AKT and p-mTOR. Interestingly, pretreatment with rapamycin, an autophagy inducer, weakened the therapeutic impact of IL-37. Conversely, the therapeutic impact of IL-37 was enhanced when treated with 3-MA, a potent autophagy inhibitor. Moreover, the inhibitory effect of IL-37 on autophagy was successfully reversed by administering AKT inhibitor MK2206. The findings suggest that IL-37 can inhibit both the inflammatory response and autophagy, leading to the alleviation of PM2.5-related LI. At the molecular level, IL-37 may exert its anti autophagy and anti apoptosis effects by activating the AKT/mTOR signaling pathway.
Assuntos
Lesão Pulmonar , Material Particulado , Proteínas Proto-Oncogênicas c-akt , Animais , Humanos , Camundongos , Autofagia/efeitos dos fármacos , Interleucinas/farmacologia , Lesão Pulmonar/induzido quimicamente , Lesão Pulmonar/tratamento farmacológico , Material Particulado/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
We have shown in the past studies that fine particulate matter (PM2.5) exposure increases airway hyperresponsiveness and leads to lung inflammation damage. Interleukin (IL)-37 plays a inhibitory role in inflammation activation and maintenance. However, the function of IL-37 in the above processes keep unclear. We aim to explore the role of IL-37 in PM2.5-induced airway hyperresponsiveness in this study. A nose-only PM2.5 online concentration, enrichment and exposure instrument was also applied to generate mice model of airway hyperresponsiveness. A transgenic mice strain using a CMV promoter to express human IL-37b (hIL-37tg) was obtained. PM2.5 exposure was shown to increase airway resistance, followed by lung inflammation and IL-1ß, TNFα, and IL-6 release, which was inhibited by IL-37tg mice and mice administrated recombinant human IL-37 intranasally (i.n). Moreover, expression of the proliferation-related protein PCNA and migration-related proteins MMP-2, MMP-9, and Vimentin was reduced in lung tissues of IL-37tg mice and mice given recombinant human IL-37 i.n. Abnormal cell contraction, proliferation, and migration of human airway smooth muscle cells (hASMCs) incubated with PM2.5 were also decreased by IL-37 treatment. In addition, IL-37 intervention of hASMCs before PM2.5 incubation decreased cytoplasmic calcium level and expression of PCNA, MMP-2, MMP-9 and Vimentin. Finally, knockdown of the IL-37 receptor IL-1R8 gene eliminated the protective effects of IL-37 in the above responses. We conclude that IL-37 inhibits inflammation activation and disease severity of airway hyperreactivity by PM2.5 induction.
Assuntos
Material Particulado , Hipersensibilidade Respiratória , Animais , Humanos , Inflamação/induzido quimicamente , Interleucina-1 , Pulmão , Camundongos , Material Particulado/toxicidade , Hipersensibilidade Respiratória/induzido quimicamente , Índice de Gravidade de DoençaRESUMO
The treatment of triple negative breast cancer (TNBC) is a significant challenge to cancer research. The lack of hormone receptors limits the treatment options available to patients with this diagnosis, forcing them to endure prolonged radiation and chemotherapy. Anti-angiogenesis is a chemotherapeutic strategy that targets the vasculature of tumors. Combretastatin A-4 (CA-4) is a well-known vasculature-disrupting agent, which has been shown to effectively kill a variety of cancers through inhibition of tubulin polymerization. Due to its toxicity, small molecule analogues of CA-4 have been sought out. We have designed a novel dual action CA-4 prodrug, YK-5-252, which releases the drug through a disulfide bond cleavage mechanism and contains a near-infrared (NIR) fluorophore, which allows fluorescence monitoring of cleavage. This disulfide linkage causes CA-4 to become effective only when released by glutathione (GSH) reducing the toxicity of the drug while simultaneously releasing the NIR fluorophore. Therefore the prodrug, YK-5-252, represents a novel CA-4 analogue which has reduced toxicity and can be used for theranostics imaging.
Assuntos
Benzopiranos/uso terapêutico , Estilbenos/uso terapêutico , Nanomedicina Teranóstica , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Benzopiranos/química , Benzopiranos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citometria de Fluxo , Humanos , Espectrometria de Massas , Espectroscopia de Prótons por Ressonância Magnética , Estilbenos/química , Estilbenos/farmacologia , Neoplasias de Mama Triplo Negativas/patologia , Moduladores de TubulinaRESUMO
The enantiomers of two analogs of Sazetidine-A as well as several other novel biosteric analogues were synthesized. Their binding affinities at three major nAChRs subtypes and selectivity profiles were determined. Though many (S)-enantiomers of Sazetidine-A analogs have high binding affinities and good subtype selectivities, it is not a general rule that (S)-enantiomers are better than their (R) counterparts. Compound 11, of which the ethynyl group was replaced by its' bioisostere-the triazole via click chemistry, showed a high binding affinity to α4ß2 subtype (Ki=1.3 nM) and better selectivity to the α4ß2 subtype over α3ß4 subtype with that of Sazetidine-A. The azide compound 15, a potential photoaffinity label, showed improved high selectivity and similar binding property profile with that of Sazetidine-A. The biaryl analog 17 exhibited a much lower affinity as compared to Sazetidine-A indicating the importance of a 'long tail' side chain for α4ß2 nAChR binding.
Assuntos
Azetidinas/farmacologia , Piridinas/farmacologia , Receptores Nicotínicos/metabolismo , Azetidinas/síntese química , Azetidinas/química , Sítios de Ligação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ligantes , Estrutura Molecular , Piridinas/síntese química , Piridinas/química , Relação Estrutura-AtividadeRESUMO
Objective: Preoperative obstructive sleep apnea (OSA) is supposed to be the abnormally high occurrence of OSA the night before surgery under general anesthesia. This study aimed to evaluate the prevalence preoperative OSA using cardiopulmonary coupling (CPC) and its correlation with imbalance of sympathetic/parasympathetic nervous system. Methods: A total of 550 patients with plans to receive surgery under general anesthesia were enrolled. All patients were assigned to wear CPC on the night before surgery until the next day. Sleep quality characteristics, heart rate variation parameters, and apnea-hypopnea index were acquired. The diagnosis of pre-existing OSA was not considered in the current study. Results: According to apnea-hypopnea index, 28.4%, 32.2%, 26.2%, and 13.3% patients were assessed as no, mild, moderate, and severe operative OSA, respectively. Multivariate logistic regression model revealed that higher age [p < 0.001, odds ratio (OR) = 1.043] was independently and positively associated with preoperative OSA; heart rate variation parameters representing the imbalance of sympathetic/parasympathetic nervous system, such as higher low-frequency (p < 0.001, OR = 1.004), higher low-frequency/high-frequency ratio (p = 0.028, OR = 1.738), lower NN20 count divided by the total number of all NN intervals (pNN20; p < 0.001, OR = 0.950), and lower high-frequency (p < 0.001, OR = 0.998), showed independent relationships with a higher probability of preoperative OSA. Higher age (p = 0.005, OR = 1.024), higher very-low-frequency (p < 0.001, OR = 1.001), and higher low-frequency/high-frequency ratio (p = 0.003, OR = 1.655) were associated with a higher probability of moderate-to-severe preoperative OSA, but higher pNN10 (p < 0.001, OR = 0.951) was associated with a lower probability of moderate-to-severe preoperative OSA. Conclusion: Preoperative OSA is prevalent. Higher age and imbalance of sympathetic/parasympathetic nervous system are independently and positively associated with a higher occurrence of preoperative OSA. CPC screening may promote the management of preoperative OSA.
RESUMO
RATIONALE: Neoglycoconjugate vaccines synthesized by the squaric acid spacer method allow single point attachment of the carbohydrate antigen to the protein carrier. However, the localization of the carbohydrate antigen sites of conjugation on the protein carrier has been an elusive task difficult to achieve. METHOD: Covalent attachment of the lactose antigen to the bovine serum albumin (BSA) was prepared by the squaric acid method using a hapten:BSA ratio of 20:1. Different reaction times were used during the conjugation reaction and two different lactose-BSA glycoconjugate vaccines were obtained. The carbohydrate antigen hapten:BSA ratios of these lactose-BSA glycoconjugate vaccines were determined by MALDI-TOF/RTOF-MS and the glycation sites in the neoglycoconjugates were determined using nano-LC/ESI-QqTOF-MS/MS analysis of the trypsin and GluC V8 digests of the conjugates. RESULTS: We have identified a total of 15 glycation sites located on the BSA lysine residues for the neoglycoconjugate vaccine formed with a hapten:BSA ratio of 5.1:1, However, the tryptic and GluC V8 digests of the hapten-BSA glycoconjugate with a hapten:BSA ratio of 19.0:1 allowed identification of 30 glycation sites located on the BSA. These last results seem to indicate that this conjugation results in formation of various glycoforms. CONCLUSIONS: It was observed that the number of identified glycation sites increased when the hapten:BSA ratio of glycoconjugate formation increased, and that the location of the glycation sites appears to be mainly on the outer surface of the BSA carrier molecule which is in line with the assumption that the sterically more accessible lysine residues, namely those located on the outer surface of the BSA, would be conjugated preferentially.
Assuntos
Lactose/química , Soroalbumina Bovina/química , Espectrometria de Massas em Tandem/métodos , Vacinas Conjugadas/química , Vacinas de Subunidades Antigênicas/química , Sequência de Aminoácidos , Animais , Bovinos , Cromatografia Líquida , Glicosilação , Haptenos/química , Haptenos/metabolismo , Lactose/imunologia , Lactose/metabolismo , Lisina/química , Lisina/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Soroalbumina Bovina/imunologia , Soroalbumina Bovina/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Vacinas Conjugadas/imunologia , Vacinas Conjugadas/metabolismo , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/metabolismoRESUMO
Injectable hydrogels have previously demonstrated potential as a temporary scaffold for tissue regeneration or as a delivery vehicle for cells, growth factors, or drugs. However, most injectable hydrogel systems lack a microporous structure, preventing host cell migration into the hydrogel interior and limiting spreading and proliferation of encapsulated cells. Herein, an injectable microporous hydrogel assembled from gelatin/gelatin methacryloyl (GelMA) composite microgels is described. Microgels are produced by a water-in-oil emulsion using a gelatin/GelMA aqueous mixture. These microgels show improved thermal stability compared to GelMA-only microgels and benefit from combined photopolymerization using UV irradiation (365 nm) in the presence of a photoinitiator (PI) and enzymatic reaction by microbial transglutaminase (mTG), which together enable fast curing and tissue adhesion of the hydrogel. The dual-crosslinking approach also allows for the reduction of PI concentration and minimizes cytotoxicity during photopolymerization. When applied for in situ cell encapsulation, encapsulated human dermal fibroblasts and human mesenchymal stem cells (hMSCs) are able to rapidly spread and proliferate in the pore space of the hydrogel. This hydrogel has the potential to enhance hMSC anti-inflammatory behavior through the demonstrated secretion of prostaglandin E2 (PGE2) and interleukin-6 (IL-6) by encapsulated cells. Altogether, this injectable formulation has the potential to be used as a cell delivery vehicle for various applications in regenerative medicine.
Assuntos
Células-Tronco Mesenquimais , Microgéis , Encapsulamento de Células , Gelatina/química , Humanos , Hidrogéis/química , Metacrilatos , Engenharia TecidualRESUMO
BACKGROUNDS: Abnormal cartilage calcification is one of the pathological changes of temporomandibular joint (TMJ) osteoarthritis (OA). Recent studies have reported that exosomes can regulate the formation of abnormal calcified nodules in diseases including atherosclerosis and chronic kidney disease. However, the influences of chondrocyte-derived exosomes on abnormal cartilage calcification in TMJ OA are still unclear. METHODS: TMJ OA was induced by unilateral anterior crossbite (UAC) for 4, 8, or 12 weeks in rats to observe abnormal calcification in TMJ condylar cartilage and exosome formation. Concomitantly, GW4869, the inhibitor of exosome formation, was locally injected to the TMJ of rats under stimulation of UAC, while the exosomes extracted from primary condylar chondrocytes stimulated with fluid flow shear stress (FFSS) were locally injected to rats TMJ. RESULTS: Abnormal calcification was enhanced in the degenerative cartilage of TMJ OA in UAC rats, and a large number of exosome-like structures with diameters of 50-150 nm were found in the calcified cartilage together with decreased expression of matrix Gla protein (MGP) and increased expression of CD63, tissue-nonspecific alkaline phosphatase (TNAP) and nucleotide pyrophosphatase/phosphodiesterase-1 (NPP1). After FFSS stimulation, the number of exosomes secreted by chondrocytes and the numbers of calcified nodules were increased in cultured cells, and the protein levels of MGP, TNAP, and NPP1 in exosomes were changed. Inhibition of exosome formation, TNAP, and NPP1 or supplementation with exogenous MGP effectively alleviated FFSS-induced chondrocyte calcification. Local injection of GW4869, the exosome inhibitor, alleviated TMJ OA-related cartilage degeneration and calcification in UAC rats. Local injection of exosomes obtained from chondrocytes stimulated by FFSS to the TMJs of normal rats induced cartilage degeneration and calcification similar to that in TMJ OA. CONCLUSIONS: Abnormal biomechanical loading leads to enhanced formation of chondrocyte-derived exosomes, in which promoters of calcification increased and inhibitors decreased, resulting in accelerating abnormal cartilage calcification in TMJ OA. The inhibition of degenerative chondrocyte-derived exosomes is expected to be a new way to prevent and treat TMJ OA.
Assuntos
Cartilagem Articular , Exossomos , Osteoartrite , Animais , Cartilagem Articular/patologia , Condrócitos/metabolismo , Exossomos/metabolismo , Osteoartrite/metabolismo , Ratos , Articulação Temporomandibular/metabolismoRESUMO
This study is to investigate the effect of Icogenin on and its mechanism in anti-metastasis of pancreatic cancer BxPC3 cells in vitro. Using transwell assay, the effects of Icogenin on the invasion of BxPC3 cells were measured. The abilities of cell motility and adhesion in BxPC3 cells were detected by MTT assay and wound healing assay, respectively. The MAPK signal pathway protein expressions were analyzed with Western blotting. Also, the activity of MMP2 was observed by zymography assay. Icogenin inhibited the abilities of motility, adhesion and invasion of pancreatic cancer BxPC3 cells in vitro (P < 0.05), in a dose-depended manner, and inhibited the secretion of MMP2 and phosphorylation of ERK. PD98059 and U0126 which were ERK inhibitors could suppress the abilities of invasion and metastasis of pancreatic cancer BxPC3 cells. It is concluded that Icogenin can inhibit the abilities of invasion and metastasis of pancreatic cancer in vitro by inhibiting the secretion of MMP2 and phosphorylation of ERK.
Assuntos
Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Neoplasias Pancreáticas/patologia , Saponinas/farmacologia , Esteroides/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Dracaena/química , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Invasividade Neoplásica , Neoplasias Pancreáticas/metabolismo , Fosforilação , Saponinas/isolamento & purificação , Transdução de Sinais , Esteroides/isolamento & purificaçãoRESUMO
A mechanically strong composite hydrogel was produced based on an interpenetrating network (IPN) between gelatin and silk fibroin. When two layers of the IPN were created, the resulting hydrogel exhibited much improved mechanical properties. This hydrogel is biodegradable and non-cytotoxic and allows for cell adhesion and proliferation on the surface.
Assuntos
Fibroínas/química , Gelatina/química , Hidrogéis/síntese química , Seda/química , Adesão Celular , Proliferação de Células , Fibroblastos/citologia , Humanos , Hidrogéis/química , Tamanho da Partícula , Pele/citologia , Propriedades de SuperfícieRESUMO
Corneal melting is an uncontrolled, excessive degradation of cellular and extracellular components of the cornea. This potential cause of corneal blindness is caused by excessive expression of zinc-dependent matrix metalloproteinases (MMPs) and has no satisfying cure as of now. Herein, we introduce a novel therapeutic hydrogel which can be made into a contact lens to slow down the progression of corneal melting by deactivating MMPs. The hydrogel backbone is comprised of poly(2-hydroxyetyl methacrylate) (pHEMA), a main material for commercial contact lenses, and dipicolylamine (DPA) which has high affinity and selectivity towards zinc ion. Due to the high affinity towards zinc ions, the DPA-conjugated pHEMA (pDPA-HEMA) hydrogel selectively removes zinc ions from a physiological buffer and deactivates MMP-1, MMP-2 and MMP-9 within 2 hours. pDPA-HEMA hydrogel also effectively prevents degradation of porcine corneas by collagenase A, a zinc-dependent protease, whereas the corneas completely degrades within 15 hours when incubated with pHEMA hydrogel. The presence of pDPA-HEMA hydrogel does not affect the viability of keratocytes and corneal epithelial cells. Unlike the conventional MMP inhibitors (MMPi), the pDPA-HEMA hydrogel minimizes the risk of serious non-specific side effects, and provides a method to slow down the progression of corneal melting and other related ocular diseases.
RESUMO
The methyl 6-hydroxyhexanoyl glycoside of lactose was treated with each of 1,2-diaminoethane or hydrazine hydrate, and the corresponding amino amide 4 and acyl hydrazide 13, were treated with each of squaric acid dimethyl, diethyl, dibutyl, and didecyl esters. The monoesters were conjugated to bovine serum albumin (BSA) at different concentrations of hapten using 0.05 and 0.5M pH 9 borate buffer. Maximum loading was achieved faster, and the conjugation efficiency was higher, when the conjugation was conducted at higher concentrations of both hapten and buffer. Conjugations involving haptens 14-17 prepared from hydrazide 13 were generally slower and less efficient than those with compounds 5-8, which were made from amino amide 4. Maintaining pH 9 during conjugation was found to be the most important factor in ensuring that the conjugation was a fast, highly efficient, and reproducible process. When the pH of the conjugation mixture fell during the reaction, resulting in decreased reaction rate or even termination of the conjugation process, the normal course of the conjugation process could be restored by addition of buffer salts. Hydrolysis studies with monoesters formed from amino amide 4 under conjugation conditions showed that decyl ester 8 was the most stable and that the methyl compound 5 was the one most readily hydrolyzed. The stability of monoesters prepared from hydrazide 13 was similar and comparable to the decyl ester prepared from 4. No definite advantage was found for the use of any of the four dialkyl squarate reagents (methyl-, ethyl-, butyl-, and decyl-) for conversion of carbohydrate derivatives to species amenable for conjugation. Nevertheless, dimethyl squarate seemed to be the most convenient reagent because it is a crystalline, easy to handle, and commercially available material with very good reactivity.
Assuntos
Ciclobutanos/química , Glicoconjugados/síntese química , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Hidrólise , Indicadores e ReagentesRESUMO
Soft tissue integration of medical implants is important to prevent bacterial infection and implant failure. A bioadhesive that forms firm binding between the implant and the surrounding tissue and facilitates the wound-healing process will be a great tool to establish the desired tissue-implant integration. In this project, we introduce a novel method that can be used to enhance integration between any implant material and any tissue using an enzyme-crosslinked gelatin hydrogel combined with polydopamine (PDA) coating. PDA coating was shown to enhance the binding between the gelatin hydrogel and three model implant materials - aluminum, poly(methyl methacrylate) (PMMA) and titanium. When combined with the gelatin hydrogel, pig cornea tissue adhered more strongly to the PDA coated surfaces than to the uncoated surfaces. The enzyme-crosslinked gelatin hydrogel was non-cytotoxic to human dermal fibroblasts and it also allowed the cells to adhere and proliferate. Altogether, the results indicate that the combination of PDA coating with gelatin hydrogel can be used to enhance the integration of various medical implants.
RESUMO
Injectable hydrogels can be useful tools for facilitating wound healing since they conform to the irregular shapes of wounds, serving as a temporary matrix during the healing process. However, the lack of inherent pore structures of most injectable hydrogels prohibits desired interactions with the cells of the surrounding tissues limiting their clinical efficacy. Here, we introduce a simple, cost-effective and highly biofunctional injectable macroporous hydrogel made of gelatin microgels crosslinked by microbial transglutaminase (mTG). Pores are created by the interstitial space among the microgels. A water-in-oil emulsion technique was used to create gelatin microgels of an average size of 250µm in diameter. When crosslinked with mTG, the microgels adhered to each other to form a bulk hydrogel with inherent pores large enough for cell migration. The viscoelastic properties of the porous hydrogel were similar to those of nonporous gelatin hydrogel made by adding mTG to a homogeneous gelatin solution. The porous hydrogel supported higher cellular proliferation of human dermal fibroblasts (hDFs) than the nonporous hydrogel over two weeks, and allowed the migration of hDFs into the pores. Conversely, the hDFs were unable to permeate the surface of the nonporous hydrogel. To demonstrate its potential use in wound healing, the gelatin microgels were injected with mTG into a cut out section of an excised porcine cornea. Due to the action of mTG, the porous hydrogel stably adhered to the cornea tissue for two weeks. Confocal images showed that a large number of cells from the cornea tissue migrated into the interstitial space of the porous hydrogel. The porous hydrogel was also used for the controlled release of platelet-derived growth factor (PDGF), increasing the proliferation of hDFs compared to the nonporous hydrogel. This gelatin microgel-based porous hydrogel will be a useful tool for wound healing and tissue engineering.
RESUMO
Epigenetic regulation of gene expression is an emerging target to treat several human diseases including cancers. In cancers, expressions of many tumor suppressor genes are suppressed by hyper-methylation in their regulatory regions. Herein, we describe a novel carbazole SH-I-14 that decreased the level of the acetyl-STAT3 at the K685 residue. Mutation analysis revealed that SH-I-14 disrupted STAT3-DNMT1 interaction by removing acetyl group from K685 of STAT3. Finally, the inhibition of STAT3-DNMT1 interaction by SH-I-14 resulted in re-expression of tumor suppressor genes such as VHL and PDLIM4 through de-methylation of their promoter regions. In addition, SH-I-14 showed anti-proliferative effect in triple-negative breast cancer (TNBC) cell lines in vitro and anti-tumor effect in a mouse xenograft model of MDA-MB-231 tumor. Taken together, our results suggest that targeting acetyl-STAT3 (K685) provides potential therapeutic opportunity to treat a subset of human cancers.
RESUMO
The facile total synthesis of the natural product (±)-mahanine was obtained in eight steps with an overall 52% yield from readily accessible known nitrophenol derivative 6. After a one-step, acid-catalyzed annulation, two additional natural products were formed including 7-hydroxymurrayazolinine, representing its first reported total synthesis. In the whole process, the introduction of the m-nitro group significantly enhanced the key pyran annulation reaction through inductive effects.
Assuntos
Alcaloides/síntese química , Produtos Biológicos/síntese química , Carbazóis/síntese química , Compostos Heterocíclicos de 4 ou mais Anéis/síntese química , Nitrocompostos/química , Piranos/química , Alcaloides/química , Produtos Biológicos/química , Carbazóis/química , Catálise , Compostos Heterocíclicos de 4 ou mais Anéis/química , Estrutura Molecular , EstereoisomerismoRESUMO
Two representative spirostanol saponins that have the typical structure for the sugar moiety, diosgenyl alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->3)]-beta-D-glucopyranoside (gracillin) and diosgenyl alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (dioscin), were easily synthesized by a general approach. A procedure using guanidine for the selective deblocking of acetyl while retaining benzoyl protecting groups is described.
Assuntos
Diosgenina/análogos & derivados , Diosgenina/síntese química , Espirostanos/síntese química , Acetilação , Configuração de Carboidratos , Guanidina/química , Saponinas/síntese químicaRESUMO
The aberrant activation of STAT3 occurs in many human cancers and promotes tumor progression. Phosphorylation of a tyrosine at amino acid Y705 is essential for the function of STAT3. Synthesized carbazole derived with fluorophore compound 12 was discovered to target STAT3 phosphorylation. Compound 12 was found to inhibit STAT3-mediated transcription as well as to reduce IL-6 induced STAT3 phosphorylation in cancer cell lines expressing both elevated and low levels of phospho-STAT3 (Y705). Compound 12 potently induced apoptosis in a broad number of TNBC cancer cell lines in vitro and was effective at inhibiting the in vivo growth of human TNBC xenograft tumors (SUM149) without any observed toxicity. Compound 12 also effectively inhibited the growth of human lung tumor xenografts (A549) harboring aberrantly active STAT3. In vitro and in vivo studies showed that the inhibitory effects of 12 on phospho-STAT3 were through up-regulation of the protein-tyrosine phosphatase PTPN6. Our present studies strongly support the continued preclinical evaluation of compound 12 as a potential chemotherapeutic agent for TNBC and cancers with constitutive STAT3 signaling.
Assuntos
Antineoplásicos/química , Carbazóis/química , Naftalenossulfonatos/química , Proteína Tirosina Fosfatase não Receptora Tipo 6/biossíntese , Fator de Transcrição STAT3/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Apoptose , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Carbazóis/síntese química , Carbazóis/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Indução Enzimática , Feminino , Xenoenxertos , Humanos , Interleucina-6/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Naftalenossulfonatos/síntese química , Naftalenossulfonatos/farmacologia , Transplante de Neoplasias , Fosforilação , Relação Estrutura-Atividade , Transcrição GênicaRESUMO
The linker-equipped disaccharide, 8-amino-3,6-dioxaoctyl 2,6-dideoxy-2-acetamido-3-O-ß-D-galactopyranosyluronate-ß-D-glucopyranoside (10), was synthesized in eight steps from acetobromogalactose and ethyl 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-1-thio-ß-D-glucopyranoside. The hydroxyl group present at C-4(II) in the last intermediate, 8-azido-3,6-dioxaoctyl 4-O-benzyl-6-bromo-2,6-dideoxy-2-trichloroacetamido-3-O-(benzyl 2,3-di-O-benzyl-ß-D-galactopyranosyluronate)-ß-D-glucopyranoside (9), is positioned to allow further build-up of the molecule and, eventually, construction of the complete hexasaccharide. Global deprotection (9â10) was done in one step by catalytic hydrogenolysis over palladium-on-charcoal.
Assuntos
Antígenos de Bactérias/química , Cólera/microbiologia , Dissacarídeos/síntese química , Vibrio cholerae O139 , Anticorpos/imunologia , Anticorpos/metabolismo , Antígenos de Bactérias/imunologia , Configuração de Carboidratos , Cólera/imunologia , Cólera/metabolismo , Dissacarídeos/imunologia , Mapeamento de Epitopos/métodos , Glicoconjugados/síntese química , Glicoconjugados/imunologia , Humanos , Imunoconjugados/química , Imunoconjugados/imunologia , Mimetismo Molecular/imunologia , Ligação Proteica , Vibrio cholerae O139/química , Vibrio cholerae O139/imunologiaRESUMO
We present herein an efficient mass spectrometric method for the localization of the glycation sites of a model neoglycoconjugate vaccine formed by a construct of the tetrasaccharide side chain of the Bacillus anthracis exosporium and the protein carrier bovine serum albumin. The glycoconjugate was digested with both trypsin and GluC V8 endoproteinases, and the digests were then analyzed by MALDI-TOF/TOF-CID-MS/MS and nano-LC-ESI-QqTOF-CID-MS/MS. The sequences of the unknown peptides analyzed by MALDI-TOF/TOF-CID-MS/MS, following digestion with the GluC V8 endoproteinase, allowed us to recognize three glycopeptides whose glycation occupancies were, respectively, on Lys 235, Lys 420, and Lys 498. Similarly, the same analysis was performed on the tryptic digests, which permitted us to recognize two glycation sites on Lys 100 and Lys 374. In addition, we have also used LC-ESI-QqTOF-CID-MS/MS analysis for the identification of the tryptic digests. However, this analysis identified a higher number of glycopeptides than would be expected from a glycoconjugate composed of a carbohydrate-protein ratio of 5.4:1, which would have resulted in glycation occupancies of 18 specific sites. This discrepancy was due to the large number of glycoforms formed during the synthetic carbohydrate-spacer-carrier protein conjugation. Likewise, the LC-ESI-QqTOF-MS/MS analysis of the GluC V8 digest also identified 17 different glycation sites on the synthetic glycoconjugate.