RESUMO
Glutamate is traditionally viewed as the first messenger to activate NMDAR (N-methyl-D-aspartate receptor)-dependent cell death pathways in stroke1,2, but unsuccessful clinical trials with NMDAR antagonists implicate the engagement of other mechanisms3-7. Here we show that glutamate and its structural analogues, including NMDAR antagonist L-AP5 (also known as APV), robustly potentiate currents mediated by acid-sensing ion channels (ASICs) associated with acidosis-induced neurotoxicity in stroke4. Glutamate increases the affinity of ASICs for protons and their open probability, aggravating ischaemic neurotoxicity in both in vitro and in vivo models. Site-directed mutagenesis, structure-based modelling and functional assays reveal a bona fide glutamate-binding cavity in the extracellular domain of ASIC1a. Computational drug screening identified a small molecule, LK-2, that binds to this cavity and abolishes glutamate-dependent potentiation of ASIC currents but spares NMDARs. LK-2 reduces the infarct volume and improves sensorimotor recovery in a mouse model of ischaemic stroke, reminiscent of that seen in mice with Asic1a knockout or knockout of other cation channels4-7. We conclude that glutamate functions as a positive allosteric modulator for ASICs to exacerbate neurotoxicity, and preferential targeting of the glutamate-binding site on ASICs over that on NMDARs may be strategized for developing stroke therapeutics lacking the psychotic side effects of NMDAR antagonists.
Assuntos
Canais Iônicos Sensíveis a Ácido , Isquemia Encefálica , Ácido Glutâmico , Animais , Feminino , Humanos , Masculino , Camundongos , 2-Amino-5-fosfonovalerato/efeitos adversos , 2-Amino-5-fosfonovalerato/metabolismo , 2-Amino-5-fosfonovalerato/farmacologia , Canais Iônicos Sensíveis a Ácido/química , Canais Iônicos Sensíveis a Ácido/deficiência , Canais Iônicos Sensíveis a Ácido/efeitos dos fármacos , Canais Iônicos Sensíveis a Ácido/genética , Canais Iônicos Sensíveis a Ácido/metabolismo , Regulação Alostérica/efeitos dos fármacos , Sítios de Ligação/genética , Isquemia Encefálica/induzido quimicamente , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Ácido Glutâmico/análogos & derivados , Ácido Glutâmico/metabolismo , Ácido Glutâmico/farmacologia , Ácido Glutâmico/toxicidade , Camundongos Knockout , Mutagênese Sítio-Dirigida , Prótons , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/química , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
OBJECTIVE: To comprehensively review and critically assess the literature on microbiota differences between patients with interstitial cystitis (IC)/bladder pain syndrome (BPS) and normal controls and to provide clinical practice guidelines. MATERIALS AND METHODS: In this systematic review, we evaluated previous research on microbiota disparities between IC/BPS and normal controls, as well as distinctions among IC/BPS subgroups. A comprehensive literature search was conducted across PubMed/MEDLINE, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials. Relevant studies were shortlisted based on predetermined inclusion and exclusion criteria, followed by quality assessment. The primary focus was identifying specific taxonomic variations among these cohorts. RESULTS: A total of 12 studies met the selection criteria. Discrepancies were adjudicated by a third reviewer. The Newcastle-Ottawa Scale was used to assess study quality. Predominantly, the studies focused on disparities in urine microbiota between IC/BPS patients and normal controls, with one study examining gut microbiota differences between the groups, and two studies exploring vaginal microbiota distinctions. Unfortunately, analyses of discrepancies in other microbiota were limited. Our findings revealed evidence of distinct bacterial abundance variations, particularly involving Lactobacillus, alongside variations in specific metabolites among IC/BPS patients compared to controls. CONCLUSIONS: Currently, there is evidence suggesting significant variations in the diversity and species composition of the urinary microbiota between individuals diagnosed with IC/BPS and control groups. In the foreseeable future, urologists should consider urine microbiota dysbiosis as a potential aetiology for IC, with potential clinical implications for diagnosis and treatment.
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Macrophages are important in inflammation, and are involved in many physiological and pathological processes. Additionally, macrophages are important producers of eicosanoids, lipids that influence the inflammatory response. Our study aimed to explore the role of eicosanoids in the inflammatory response by studying the production of eicosanoids by macrophages on different stages of inflammation. Murine peritoneal macrophages (MPMs) were obtained at different stages of inflammation, which were then cultured in vitro with polyunsaturated fatty acids. Eicosanoids in MPMs were then detected by liquid chromatography-mass spectrometry. The metabolites derived from the cyclooxygenase (COX) pathway were increased, whereas those from the lipoxygenase (LOX) pathway were reduced. Additionally, the ratio of arachidonic acid (AA)-derived and eicosapentaenoic acid (EPA)-derived eicosanoids was dependent on the stage of inflammation. Moreover, the composition of macrophages with different phenotypes changed. To clarify the relationship between the phenotypes of macrophages and eicosanoids metabolism, we detected the eicosanoids in M1 and M2 differentiated THP-1 cells. Overall, M1 preferred AA, whereas M2 preferred EPA as substrate, which was related to the expression of COX and LOX. In conclusion, this study demonstrates that the difference in macrophage eicosanoids metabolism during the inflammatory response is related to the macrophage polarisation.
Assuntos
Eicosanoides , Macrófagos , Animais , Ácido Araquidônico/metabolismo , Eicosanoides/metabolismo , Ácido Eicosapentaenoico/metabolismo , Inflamação/metabolismo , Macrófagos/metabolismo , Camundongos , FenótipoRESUMO
PURPOSE: Ferroptosis is a form of regulated cell death that has the potential to be targeted as a cancer therapeutic strategy. But cancer cells have a wide range of sensitivities to ferroptosis, which limits its therapeutic potential. Accumulation of lipid peroxides determines the occurrence of ferroptosis. However, the type of lipid involved in peroxidation and the mechanism of lipid peroxide accumulation are less studied. METHODS: The effects of fatty acids (10 µM) with different carbon chain length and unsaturation on ferroptosis were evaluated by MTT and LDH release assay in cell lines derived from prostate cancer (PC3, 22RV1, DU145 and LNCaP), colorectal cancer (HT-29), cervical cancer (HeLa) and liver cancer (HepG2). Inhibitors of apoptosis, necroptosis, autophagy and ferroptosis were used to determine the type of cell death. Then the regulation of reactive oxygen species (ROS) and lipid peroxidation by docosahexaenoic acid (DHA) was measured by HPLC-MS and flow cytometry. The avtive form of DHA was determined by siRNA mediated gene silencing. The role of lipoxygenases was checked by inhibitors and gene silencing. Finally, the effect of DHA on ferroptosis-mediated tumor killing was verified in xenografts. RESULTS: The sensitivity of ferroptosis was positively correlated with the unsaturation of exogenously added fatty acid. DHA (22:6 n-3) sensitized cancer cells to ferroptosis-inducing reagents (FINs) at the highest level in vitro and in vivo. In this process, DHA increased ROS accumulation, lipid peroxidation and protein oxidation independent of its membrane receptor, GPR120. Inhibition of long chain fatty acid-CoA ligases and lysophosphatidylcholine acyltransferases didn't affect the role of DHA. DHA-involved ferroptosis can be induced in both arachidonate lipoxygenase 5 (ALOX5) negative and positive cells. Down regulation of ALOX5 inhibited ferroptosis, while overexpression of ALOX5 promoted ferroptosis. CONCLUSION: DHA can effectively promote ferroptosis-mediated tumor killing by increasing intracellular lipid peroxidation. Both ALOX5 dependent and independent pathways are involved in DHA-FIN induced ferroptosis. And during this process, free DHA plays an important role.
Assuntos
Ácidos Docosa-Hexaenoicos , Neoplasias , Masculino , Humanos , Ácidos Docosa-Hexaenoicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Peróxidos Lipídicos , Lipoxigenase/metabolismo , Lipoxigenase/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Lisofosfatidilcolinas/farmacologia , Linhagem Celular Tumoral , Morte Celular , Peroxidação de Lipídeos , Lipoxigenases/metabolismo , Araquidonato Lipoxigenases/metabolismo , Araquidonato Lipoxigenases/farmacologia , Aciltransferases/metabolismo , Aciltransferases/farmacologia , Carbono , Coenzima A/metabolismo , Coenzima A/farmacologiaRESUMO
The genomic and carbohydrate metabolic features of Pseudoalteromonas agarivorans Hao 2018 (P. agarivorans Hao 2018) were investigated through pan-genomic and transcriptomic analyses, and key enzyme genes that may encode the process involved in its extracellular polysaccharide synthesis were screened. The pan-genome of the P. agarivorans strains consists of a core-genome containing 2331 genes, an accessory-genome containing 956 genes, and a unique-genome containing 1519 genes. Clusters of Orthologous Groups analyses showed that P. agarivorans harbors strain-specifically diverse metabolisms, probably representing high evolutionary genome changes. The Kyoto Encyclopedia of Genes and Genomes and reconstructed carbohydrate metabolic pathways displayed that P. agarivorans strains can utilize a variety of carbohydrates, such as d-glucose, d-fructose, and d-lactose. Analyses of differentially expressed genes showed that compared with the stationary phase (24 h), strain P. agarivorans Hao 2018 had upregulated expression of genes related to the synthesis of extracellular polysaccharides in the logarithmic growth phase (2 h), and that the expression of these genes affected extracellular polysaccharide transport, nucleotide sugar synthesis, and glycosyltransferase synthesis. This is the first investigation of the genomic and metabolic features of P. agarivorans through pan-genomic and transcriptomic analyses, and these intriguing discoveries provide the possibility to produce novel marine drug lead compounds with high biological activity.
Assuntos
Pseudoalteromonas , Transcriptoma , Carboidratos , Genoma Bacteriano/genética , Genômica , Filogenia , Pseudoalteromonas/genética , Pseudoalteromonas/metabolismoRESUMO
Exopolysaccharides (EPSs) are carbohydrate polymers produced and secreted by microorganisms. In a changing marine environment, EPS secretion can reduce damage from external environmental disturbances to microorganisms. Meanwhile, EPSs have promising application prospects in the fields of food, cosmetics, and pharmaceuticals. Changes in external environmental pH have been shown to affect the synthesis of EPSs in microorganisms. In this study, we analyzed the effects of different initial fermentation pHs on the production, monosaccharide composition, and antioxidant activity of the EPSs of Pseudoalteromonas agarivorans Hao 2018. In addition, the transcriptome sequence of P. agarivorans Hao 2018 under different initial fermentation pH levels was determined. GO and KEGG analyses showed that the differentially expressed genes were concentrated in the two-component regulatory system and bacterial chemotaxis pathways. We further identified the expression of key genes involved in EPS synthesis during pH changes. In particular, the expression of genes encoding the glucose/galactose MFS transporter, phosphomannomutase, and mannose-1-phosphate guanylyltransferase was upregulated when the environmental pH increased, thus promoting EPS synthesis. This study not only contributes to elucidating the environmental adaptation mechanisms of P. agarivorans, but also provides important theoretical guidance for the directed development of new products using biologically active polysaccharides.
Assuntos
Antioxidantes/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificação , Pseudoalteromonas/metabolismo , Antioxidantes/química , Antioxidantes/farmacologia , Fermentação , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Concentração de Íons de Hidrogênio , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Pseudoalteromonas/genéticaRESUMO
Alternative polarization of macrophages regulates multiple biological processes. While M1-polarized macrophages generally mediate rapid immune responses, M2-polarized macrophages induce chronic and mild immune responses. In either case, polyunsaturated fatty acid (PUFA)-derived lipid mediators act as both products and regulators of macrophages. Prostaglandin E3 (PGE3 ) is an eicosanoid derived from eicosapentaenoic acid, which is converted by cyclooxygenase, followed by prostaglandin E synthase successively. We found that PGE3 played an anti-inflammatory role by inhibiting LPS and interferon-γ-induced M1 polarization and promoting interleukin-4-mediated M2 polarization (M2a). Further, we found that although PGE3 had no direct effect on the growth of prostate cancer cells in vitro, PGE3 could inhibit prostate cancer in vivo in a nude mouse model of neoplasia. Notably, we found that PGE3 significantly inhibited prostate cancer cell growth in a cancer cell-macrophage co-culture system. Experimental results showed that PGE3 inhibited the polarization of tumour-associated M2 macrophages (TAM), consequently producing indirect anti-tumour activity. Mechanistically, we identified that PGE3 regulated the expression and activation of protein kinase A, which is critical for macrophage polarization. In summary, this study indicates that PGE3 can selectively promote M2a polarization, while inhibiting M1 and TAM polarization, thus exerting an anti-inflammatory effect and anti-tumour effect in prostate cancer.
Assuntos
Alprostadil/análogos & derivados , Anti-Inflamatórios/farmacologia , Diferenciação Celular , Inflamação/tratamento farmacológico , Ativação de Macrófagos/imunologia , Neoplasias da Próstata/tratamento farmacológico , Alprostadil/farmacologia , Animais , Polaridade Celular , Humanos , Inflamação/imunologia , Inflamação/patologia , Ativação de Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , Transdução de SinaisRESUMO
Plastic polarization of macrophage is involved in tumorigenesis. M1-polarized macrophage mediates rapid inflammation, entity clearance and may also cause inflammation-induced mutagenesis. M2-polarized macrophage inhibits rapid inflammation but can promote tumour aggravation. ω-3 long-chain polyunsaturated fatty acid (PUFA)-derived metabolites show a strong anti-inflammatory effect because they can skew macrophage polarization from M1 to M2. However, their role in tumour promotive M2 macrophage is still unknown. Resolvin D1 and D2 (RvD1 and RvD2) are docosahexaenoic acid (DHA)-derived docosanoids converted by 15-lipoxygenase then 5-lipoxygenase successively. We found that although dietary DHA can inhibit prostate cancer in vivo, neither DHA (10 µmol/L) nor RvD (100 nmol/L) can directly inhibit the proliferation of prostate cancer cells in vitro. Unexpectedly, in a cancer cell-macrophage co-culture system, both DHA and RvD significantly inhibited cancer cell proliferation. RvD1 and RvD2 inhibited tumour-associated macrophage (TAM or M2d) polarization. Meanwhile, RvD1 and RvD2 also exhibited anti-inflammatory effects by inhibiting LPS-interferon (IFN)-γ-induced M1 polarization as well as promoting interleukin-4 (IL-4)-mediated M2a polarization. These differential polarization processes were mediated, at least in part, by protein kinase A. These results suggest that regulation of macrophage polarization using RvDs may be a potential therapeutic approach in the management of prostate cancer.
Assuntos
Antineoplásicos/farmacologia , Ácidos Docosa-Hexaenoicos/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Animais , Biomarcadores , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Humanos , Imuno-Histoquímica , Macrófagos/metabolismo , Camundongos , Camundongos Transgênicos , Transdução de Sinais/efeitos dos fármacos , Macrófagos Associados a Tumor/efeitos dos fármacos , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/metabolismoRESUMO
In recent years, the wide application of exopolysaccharides (EPSs) in food, cosmetics, medicine, and other fields has drawn tremendous attention. In this study, an EPS produced by Pseudoalteromonas agarivorans Hao 2018 was isolated and purified, and its fermentation conditions were optimized. Its structure and biological functions were also studied. The purity and molecular weight of EPS were determined by high performance liquid chromatography (HPLC), and the EPS exhibited a number average of 2.26 × 105 and a weight average of 2.84 × 105. EPS has good adsorption for Cu2+ and Pb2+. The adsorption rates can reach up to 69.79% and 82.46%, respectively. The hygroscopic property of EPS was higher than that of chitosan, but slightly lower than that of sodium hyaluronate. However, the water-retaining activity of EPS was similar to that of chitosan and sodium hyaluronate. EPS has strong ability to scavenge free radicals, including OH radical and O2- radical. Further, its activity on O2- radicals has similarities with that of vitamin C. EPS has broad application prospects in many fields, such as cosmetics, environmental protection.
Assuntos
Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Pseudoalteromonas/metabolismo , Adsorção , Cobre/química , Fermentação , Sequestradores de Radicais Livres , Chumbo/química , Polissacarídeos Bacterianos/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
BACKGROUND: Stroke is the leading cause of mortality and disability worldwide. Several definite risk factors have been identified for stroke, although infectious factors might also contribute to stroke episodes through increased susceptibility or direct induction. CASE PRESENTATION: A 46-year-old Chinese male initially presented with fever, headache, and impaired memory and developed disturbance of consciousness after admission. A clinical diagnosis of Staphylococcus aureus sepsis, massive cerebral infarction and haemorrhagic transformation (left internal carotid arterial system, inflammatory thrombus) were made based on brain radiography, blood culture and postoperative pathological examinations. These symptoms improved following antibiotic therapy with vancomycin and conventional treatments for stroke. CONCLUSION: For stroke patients without traditional cerebrovascular risk factors but with signs of infection, infectious causes should be considered.
Assuntos
Arterite/complicações , Trombose das Artérias Carótidas/complicações , Acidente Vascular Cerebral/etiologia , Infarto Cerebral/complicações , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Interleukin 17 (IL-17), produced mainly by T helper 17 (Th17) cells, is increasingly recognized as a key regulator in various autoimmune diseases, including human multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Although several microRNAs (miRNAs) with aberrant expression have been shown to contribute to the pathogenesis of MS and EAE, the mechanisms underlying the regulation of abnormal miRNA expression in astrocytes upon IL-17 stimulation remain unclear. In the present study, we detected the changes of miRNA expression profiles both in the brain tissue of EAE mice and in cultured mouse primary astrocytes stimulated with IL-17 and identified miR-873 as one of the co-up-regulated miRNAs in vivo and in vitro. The overexpression of miR-873, demonstrated by targeting A20 (TNFα-induced protein 3, TNFAIP3), remarkably reduced the A20 level and promoted NF-κB activation in vivo and in vitro as well as increasing the production of inflammatory cytokines and chemokines (i.e. IL-6, TNF-α, MIP-2, and MCP-1/5). More importantly, silencing the endogenous miR-873 or A20 gene with lentiviral vector of miR-873 sponge (LV-miR-873 sponge) or short hairpin RNA (shRNA) of A20 (LV-A20 shRNA) in vivo significantly lessened or aggravated inflammation and demyelination in the central nervous system (CNS) of EAE mice, respectively. Taken together, these findings indicate that miR-873 induced by IL-17 stimulation promotes the production of inflammatory cytokines and aggravates the pathological process of EAE mice through the A20/NF-κB pathway, which provides a new insight into the mechanism of inflammatory damage in MS.
Assuntos
Cisteína Endopeptidases/metabolismo , Encefalomielite Autoimune Experimental/metabolismo , Interleucina-17/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , MicroRNAs/metabolismo , Regiões 3' não Traduzidas , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Doenças Desmielinizantes , Regulação da Expressão Gênica , Inflamação , Lentivirus/genética , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfaRESUMO
CCAAT/enhancer-binding protein (C/EBPß)-enhanced IL-6 and TGF-ß1 promoter activity and p300-mediated C/EBPß acetylation were involved in up-regulation of IL-6 and TGF-ß1 expression in GMCs attacked by sublytic C5b-9. In detail, the elements of C/EBPß binding to rat IL-6 and TGF-ß1 promoter and 3 acetylated sites of rat C/EBPß protein were first revealed. Furthermore, silencing the p300 or C/EBPß gene in rat kidney significantly reduced the production of IL-6 and TGF-ß1 and renal lesions in Thy-1N rats. Together, these data indicate that the mechanism of IL-6 and TGF-ß1 production in renal tissue of Thy-1N rats is associated with sublytic C5b-9 up-regulated p300 and p300-mediated C/EBPß acetylation as well as C/EBPß-activated IL-6 and TGF-ß1 genes.
Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/fisiologia , Mesângio Glomerular/metabolismo , Interleucina-6/biossíntese , Nefrite/metabolismo , Fator de Crescimento Transformador beta1/biossíntese , Fatores de Transcrição de p300-CBP/metabolismo , Acetilação , Animais , Sequência de Bases , Células Cultivadas , Primers do DNA , Mesângio Glomerular/citologia , Interleucina-17/biossíntese , Masculino , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo RealRESUMO
SCOPE: Epidemiological studies have linked excessive red and processed meat intake to gut disorders. Under laboratory conditions, high heme content is considered the primary health risk factor for red meat. However, heme in meat is present in myoglobin, which is an indigestible protein, suggesting the different functions between myoglobin and heme. This study aims to explore how dietary myoglobin and heme affect gut health and microbiota differently. METHODS AND RESULTS: Histological and biochemical assessments as well as 16S rRNA sequencing are performed. Moderate myoglobin intake (equivalent to the recommended intake of 150 g meat per day for human) has beneficial effects on the duodenal barrier. However, a too high myoglobin diet (equivalent to intake of 3000 g meat per day for human) triggers duodenum injury and alters the microbial community. The hemin diet destroys intestinal tissue and ileal microbiota more significantly. The in vitro experiments further confirm that free heme exhibits high toxicity to beneficial gut bacteria while myoglobin promotes the growth and metabolism of Limosilactobacillus reuteri. CONCLUSION: Moderate intake of myoglobin or hemin is beneficial to intestinal health and microbiota, but too high amounts lead to tissue inflammation and injury in the small intestine by reshaping ileal microbiota.
Assuntos
Microbioma Gastrointestinal , Hemina , Inflamação , Mioglobina , Microbioma Gastrointestinal/efeitos dos fármacos , Animais , Mioglobina/metabolismo , Hemina/farmacologia , Masculino , Dieta/métodos , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Limosilactobacillus reuteri , Duodeno/metabolismo , RNA Ribossômico 16S/genética , HemeRESUMO
This study aimed to examine the impact of sodium tripolyphosphate (STPP) on the quality and digestive characteristics of PSE pork. The results showed a notable decrease in cooking loss of PSE pork from 29.11% to 25.67% with increasing STPP concentration (P < 0.05). Additionally, the gastric digestibility of PSE pork decreased significantly from 52.01% to 45.81% (P < 0.05). The particle size of digesta decreased significantly after gastrointestinal digestion (P < 0.05). These changes were primarily due to the enhanced cross-linking of proteins through ionic interactions, hydrogen bonds and hydrophobic interactions, and resulted in the embedding of hydrophobic groups and endogenous fluorophores. Furthermore, denser network was formed. These findings give a new insight into considering the impact of STPP on meat nutrition when used to enhance texture and water holding capacity.
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Cigarettes with pronounced astringency can diminish consumers' enjoyment. However, due to the complex composition of cigarettes, quantifying astringency intensity accurately has been challenging. To address this, research was conducted to develop a method for assessing astringency intensity in a simulated oral environment. The astringency intensity of four cigarette brands was determined using the standard sensory evaluation method. The mainstream smoke absorbing solution (MS) was prepared by simulating the cigarette smoking process, and its physicochemical properties (such as total phenol content and pH levels) were analyzed. The lubrication properties of the five solutions were tested using the MFT-5000 wear tester, and factors influencing cigarette astringency were examined. The findings showed that total phenol content and pH of MS were positively and negatively correlated with astringency intensity, respectively. Particularly, the lubrication properties of MS were significantly correlated with astringency intensity, and the correlation coefficient was affected by load and speed during testing. The study concluded that coefficient of friction was a more reliable measure for assessing the extent of astringency in cigarettes than the total phenol content and pH of MS, offering new insights into astringency evaluation and development of high-grade cigarettes.
Assuntos
Paladar , Produtos do Tabaco , Humanos , Produtos do Tabaco/análise , Adulto , Masculino , Concentração de Íons de Hidrogênio , Feminino , Adulto Jovem , Lubrificação , Fumaça/análise , Adstringentes/análise , Boca , Fenóis/análise , Fumar , Pessoa de Meia-IdadeRESUMO
Myoglobin (Mb) responsible for meat color is easily oxidized resulting in meat discoloration. Here, betanin red (BR), as a natural pigment and antioxidant, was chosen for enhancing redness and inhibiting oxidation. Multiple spectroscopies, isothermal titration calorimetry and molecular docking demonstrated that BR changed the microenvironment of heme group and amino acid residues of Mb, inhibited the oxidation of oxymyoglobin. The main interaction force was hydrogen bond and one variable binding site provided a continuous protective barrier to realize antioxidation. The combination of antioxidation with the inherent red color of BR offered dual color protection effect on processed beef with the addition amount of 0.2 % BR. BR treatment enhanced the redness by 25.59 â¼ 53.24 % and the sensory acceptance by 4.89 â¼ 14.24 %, and decreased the lipid oxidation by 0.58 â¼ 15.92 %. This study paves a theoretical basis for the application of BR and its structural analogues in meat color protection and other quality improvement.
Assuntos
Mioglobina , Carne Vermelha , Animais , Bovinos , Mioglobina/química , Antioxidantes/metabolismo , Simulação de Acoplamento Molecular , Betacianinas , Carne/análise , Oxirredução , Cor , Carne Vermelha/análiseRESUMO
Osteoporosis (OP) is a common and complex chronic metabolic disease with an increasing incidence rate, which has markedly increased the human health burden worldwide. The predominant cause of OP is an imbalance between osteoblasts (OB) and osteoclasts (OC). Studies on the correlation between bone marrow-derived mesenchymal stem cells (BMSCs) and OP have indicated that BMSCs-induced OB differentiation is an important pathway for bone tissue renewal. Chinese medicinal herbs have been used for centuries to treat various types of OPs because they are safer and more effective. The in vivo and in vitro experiments have confirmed that these herbs or their primary phytochemicals may exert therapeutic effects by stimulating BMSCs differentiation, which restores OB and OP balance, inhibits adipocyte differentiation, exerts anti-inflammatory and antioxidant effects, regulates the immune system, etc. This review summarizes the research on how Chinese medicinal herbs or their primary phytochemicals treat OP by stimulating BMSC differentiation and provides a scientifically reliable basis and perspective for their future clinical application.
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The apoptosis of glomerular mesangial cells (GMC) in rat Thy-1 nephritis (Thy-1N), a model of human mesangioproliferative glomerulonephritis, is accompanied by sublytic C5b-9 deposition, but the mechanism of sublytic C5b-9-mediated GMC apoptosis has not been elucidated. In the present study, the gene expression profiles both in the GMC stimulated by sublytic C5b-9 and the rat renal tissue of Thy-1N were detected using microarrays. Among the co-up-regulated genes, the up-regulation of interferon regulatory factor-1 (IRF-1) was further confirmed. Increased caspase 8 and caspase 3 expression and caspase 8 promoter activity in the GMC were also identified. Meanwhile, overexpression or knockdown of IRF-1 not only enhanced or inhibited GMC apoptosis and caspase 8 and 3 induction but also increased or decreased caspase 8 promoter activity, respectively. The element of IRF-1 binding to the caspase 8 promoter was first revealed. Furthermore, silencing IRF-1 or repressing the activation of caspases 8 and 3 significantly reduced GMC apoptosis, including other pathologic changes of Thy-1N. These novel findings indicate that GMC apoptosis of Thy-1N is associated with the IRF-1-activated caspase 8 pathway.
Assuntos
Apoptose , Caspase 8/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Glomerulonefrite Membranoproliferativa/metabolismo , Fator Regulador 1 de Interferon/metabolismo , Células Mesangiais/metabolismo , Animais , Caspase 3/genética , Caspase 3/metabolismo , Caspase 8/genética , Linhagem Celular , Complexo de Ataque à Membrana do Sistema Complemento/genética , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Glomerulonefrite Membranoproliferativa/induzido quimicamente , Glomerulonefrite Membranoproliferativa/genética , Glomerulonefrite Membranoproliferativa/patologia , Humanos , Fator Regulador 1 de Interferon/genética , Isoanticorpos/efeitos adversos , Isoanticorpos/farmacologia , Células Mesangiais/patologia , Ratos , Elementos de Resposta/genéticaRESUMO
The proliferation of glomerular mesangial cells (GMCs) and secretion of extracellular matrix (ECM) in rat Thy-1 nephritis (Thy-1N), resembling human mesangioproliferative glomerulonephritis (MsPGN), have been studied for many years, but the mechanisms, especially the role of signalling pathway activation and its regulation in GMCs triggered by sublytic C5b-9 complexes in Thy-1N rats remain largely unclear. In the study, the proliferation of GMCs and production of ECM as well as the role of PI3K/Akt and its regulation, both in GMCs induced by sublytic C5b-9 (in vitro) and in the renal tissues of rats with Thy-1N (in vivo), were determined and the results revealed that GMCs proliferation and ECM secretion, both in vitro and in vivo, were notably increased, and that PI3K/Akt1 activation and its regulation, such as TNF receptor-associated factor 6 (TRAF6)-mediated Akt1 ubiquitination and PI3K-dependent Akt1 phosphorylation, were involved in the process of Thy-1N induction. On the other hand, silence of the TRAF6, PI3K or Akt1 genes could obviously diminish the proliferative damages and urinary protein secretion of Thy-1N rats. Together, these data implicated that sublytic C5b-9 complexes in Thy-1N rats could promote GMCs proliferation and ECM production through TRAF6-mediated PI3K-dependent Akt1 activation, in which the ubiquitination and phosphorylation of the Akt1 signal molecule played an important role in the initiation and development of the proliferative changes in the rats with Thy-1N.