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1.
Mol Psychiatry ; 28(8): 3459-3474, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37365241

RESUMO

Depression is a common and severe mental disorder. Evidence suggested a substantial causal relationship between stressful life events and the onset of episodes of major depression. However, the stress-induced pathogenesis of depression and the related neural circuitry is poorly understood. Here, we investigated how cholecystokinin (CCK) and CCKBR in the basolateral amygdala (BLA) are implicated in stress-mediated depressive-like behavior. The BLA mediates emotional memories, and long-term potentiation (LTP) is widely considered a trace of memory. We identified that the cholecystokinin knockout (CCK-KO) mice impaired LTP in the BLA, while the application of CCK4 induced LTP after low-frequency stimulation (LFS). The entorhinal cortex (EC) CCK neurons project to the BLA and optogenetic activation of EC CCK afferents to BLA-promoted stress susceptibility through the release of CCK. We demonstrated that EC CCK neurons innervate CCKBR cells in the BLA and CCK-B receptor knockout (CCKBR-KO) mice impaired LTP in the BLA. Moreover, the CCKBR antagonists also blocked high-frequency stimulation (HFS) induced LTP formation in the BLA. Notably, CCKBR antagonists infusion into the BLA displayed an antidepressant-like effect in the chronic social defeat stress model. Together, these results indicate that CCKBR could be a potential target to treat depression.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Humanos , Camundongos , Animais , Potenciação de Longa Duração/fisiologia , Receptor de Colecistocinina B/fisiologia , Depressão/tratamento farmacológico , Colecistocinina/farmacologia , Colecistocinina/fisiologia
2.
Brain Behav Immun ; 109: 23-36, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36581303

RESUMO

Synapse loss in medial prefrontal cortex (mPFC) has been implicated in stress-related mood disorders, such as depression. However, the exact effect of synapse elimination in the depression and how it is triggered are largely unknown. Through repeated longitudinal imaging of mPFC in the living brain, we found both presynaptic and postsynaptic components were declined, together with the impairment of synapse remodeling and cross-synaptic signal transmission in the mPFC during chronic stress. Meanwhile, chronic stress also induced excessive microglia phagocytosis, leading to engulfment of excitatory synapses. Further investigation revealed that the elevated complement C3 during the stress acted as the tag of synapses to be eliminated by microglia. Besides, chronic stress induced a reduction of the connectivity between the mPFC and neighbor regions. C3 knockout mice displayed significant reduction of synaptic pruning and alleviation of disrupted functional connectivity in mPFC, resulting in more resilience to chronic stress. These results indicate that complement-mediated excessive microglia phagocytosis in adulthood induces synaptic dysfunction and cortical hypo-connectivity, leading to stress-related behavioral abnormality.


Assuntos
Microglia , Derrota Social , Camundongos , Animais , Sinapses , Camundongos Knockout , Plasticidade Neuronal
3.
Sensors (Basel) ; 23(20)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37896441

RESUMO

Recent advances in roller coasters accelerate the creation of complex tracks to provide stimulation and excitement for humans. As the main load-bearing component, tracks are prone to damage such as loose connecting bolts, paint peeling, corroded sleeper welds, corroded butt welds, reduced track wall thickness and surface cracks under complex environments and long-term alternating loads. However, inspection of the roller coaster tracks, especially the high-altitude rolling tracks, is a crucial problem that traditional manual detection methods have difficulty solving. In addition, traditional inspection is labor-intensive, time-consuming, and provides only discrete information. Here, a concept of the multifunctional detection robot with a mechanical structure, electrical control system, camera, electromagnetic ultrasonic probes and an array of eddy current probes for detecting large roller coaster tracks is reported. By optimizing the design layout, integrating multiple systems and completing machine testing, the multifunctional roller coaster track detection robot exhibits outstanding performance in track appearance, thickness and crack detection. This study provides great potential for intelligent detection in amusement equipment, railcar, train and so on.

4.
Plant Dis ; 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35549323

RESUMO

As a commonly traditional Chinese medicine, the perennial herb Dangshen (Codonopsis pilosula) has superior curative effects including regulating immunity, strengthening the spleen, and tonifying lungs (Bai et al. 2020). To imitate natural ecological conditions, plants were grown on hillside fields with stems prostrate on the ground, tangle-up with each other. In August 2020, leaf spots were observed on C. pilosula in Wutai county, Shanxi province, China, and indicated a high disease incidence (70%-80%) in investigated fields (6.67 ha). Small brown necrotic spots, occasionally enclosed by chlorotic halos, were observed on leaves, stems, and sepals. For identification of the pathogen, 15 small pieces (5×5 mm) of symptomatic tissues from 5 randomly-collected diseased plants were surface sterilized, placed on potato dextrose agar plates, and incubated for 4 d in darkness at 25 °C to obtain the colonies. Cultures were purified by single spore isolation from these colonies. A total of 15 isolates named as Dcp-3, and Dcp-5~Dcp-18 were recovered. They produced ovoid or obclavate spores with 15.9-57.5×9.1-20.1 µm in size, 1-6 transverse septa, and 0-4 longitudinal septa. The conidial chains with 4 to 6 spores had numerous secondary and occasionally tertiary chains on potato carrot agar plates. Because all isolates had identical morphological traits, five genes from the representative isolate Dcp-3, actin (ACT), Alternaria major allergen (Alt a1), plasma membrane ATPase (ATP), histone 3 (H3), and rDNA ITS, were amplified with primer pairs ACTDF1/ACTDR1, Alt-for/Alt-rev, ATPDF1/ATPDR1, H3-1a/H3-1b, and ITS1/ITS4, respectively (Hong et al. 2005; Lawrence et al. 2013; Ma et al. 2020). BLASTn searches indicated species of Dcp-3 could not be accurately confirmed by rDNA ITS, ATP, ACT, and Alt a1 (GenBank accession nos. OM334894, OM362504, OM326344, OM362500). Phylogenetic analysis showed it was most closely related to Alternaria alternata, A. arborescens, and A. tenuissima based on concatenated sequences of above four genes. The H3 sequence (OM362508) shared 100% homology with that of A. alternata (MN481948). The phylogenetic tree using H3 also confirmed Dcp-3 as A. alternata. Heathly, two-year-old C. pilosula were transplanted to a greenhouse. A surface-sterilized leaf was sprayed with 50 µL spore suspension (106 conidia/mL) of Dcp-3. A leaf sprayed with isometric sterile water was used as controls. Each treatment used six plants (five leaves per plant). Plants were covered with sterilized plastic bags and incubated at 22 ℃. The test was repeated twice. A week later, control leaves were healthy, but brown necrotic spots similar to field symptoms emerged on treated leaves. The A. alternata isolates were re-isolated from the border of lesions, and confirmed by morphological and molecular characteristics mentioned above, fulfilling Koch's postulates. Leaf spot of C. pilosula caused by Septoria codonopsidis has been reported in China (Wang et al. 2011). However, to our knowledge, this is the first report of A. alternata inciting leaf spot of C. pilosula in China. Our report would promote growers to enhance the field management and consider associated strategies on controlling Alternaria leaf spot of C. pilosula.

5.
Plant Dis ; 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36265156

RESUMO

Dangshen (Codonopsis pilosula) is a well-known medicinal and food homologous plant in China, which is widely used as a tonic agent and has good immunomodulatory effects (Bai et al. 2020; Luan et al. 2021). To retain the best medicinal properties, growers imitated the original ecological planting method for cultivating C. pilosula in hillside fields in Wutai county, Shanxi province, China. In July and August 2021 and 2022, stem canker disease was observed in C. pilosula. The basal part of the stems showed slightly sunken brown lesions, and the disease incidence was up to 20% in the investigated fields (6.67 ha). To identify the causal agents of stem canker, 12 small pieces (approximately 5 mm long) from 12 diseased samples (one piece per sample) were cut from the border of the lesions, surface-sterilized (70% ethanol for 30 s, 0.5% NaClO for 3 min), washed three times with sterile water, and then incubated on water agar (WA) at 25 °C for 24 h. Isolates with right-angle branching, a septum near the branch, and a slight constriction at the branch base were selected, and their hyphal tips were transferred onto potato dextrose agar (PDA) plates. After incubation at 25 °C, 12 Rhizoctonia-like isolates (Dcp-19 to Dcp-30) with white colonies were obtained. White monilioid cells in aerial mycelia formed as they aged but did not produce sclerotia. Based on nuclear fluorescence staining with 1 µg·mL-1 4'-6-diamidino-2-phenylindole as described by Ahvenniemi et al. (2009), there were two nuclei per hyphal cell for all the 12 isolates. Moreover, the sequences of internal transcribed spacer region of ribosomal DNA (rDNA-ITS) of all the 12 isolates were amplified using the primers ITS1/ITS4 (White et al. 1990). For identical sequences, only the rDNA-ITS sequence (674 bp) of Dcp-19 has been deposited in GenBank (accession no. ON004932) and BLASTn analyses showed 100% homology with Rhizoctonia AG-K (MF070696). Maximum likelihood phylogenetic analysis further confirmed the identification. Healthy C. pilosula plants grown for two years in hillside fields were transplanted into sterile soil for pathogenicity testing. And the 12 isolates were all done in this test. Sterilized wheat seeds were placed on a 2-day-old colony of the isolate and incubated for 7 days. One fungus-infested seed was placed at the base of the stem and covered with sterilized soil. Control plants were inoculated with sterilized wheat seeds. Tests were performed on three plants for each isolate. The experiment was repeated twice. All the plants were cultivated at 22 °C and 50% relative humidity. After three weeks, the basal stems of the control plants were still healthy and did not have lesions, but the treated plants exhibited sunken brown canker lesions. The mean disease incidence of all the 12 isolates was 58.33%. The AG-K isolates re-isolated from the lesions of treated plants were confirmed by the morphological and molecular characteristics mentioned above, fulfilling Koch's postulates. To our knowledge, this is the first report of stem canker on C. pilosula caused by binucleate Rhizoctonia AG-K in China.

6.
J Sci Food Agric ; 102(7): 2750-2760, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34719036

RESUMO

BACKGROUND: The phenol oxidative pathway during fermentation remains unclear. To elucidate the effect of fermentation on phenol conversion, we investigated the effects of fermentation temperature and duration on the conversion of catechins and the formation of theasinensins (TSs), theaflavins (TFs), thearubigins (TRs), and theabrownins (TBs). RESULTS: During fermentation, TSs formation increased initially and then decreased. Long fermentation durations were unfavorable for liquor brightness (LB) and resulted in the production of large amounts of TRs and TBs. Low fermentation temperatures (20 °C and 25 °C) favored the maintenance of polyphenol oxidase activity and the continuous formation of TFs, TSs, and TRSI (a TRs fraction), resulting in better LB and liquor color. Higher temperatures (30 °C, 35 °C, and 40 °C) resulted in higher peroxidase activity, higher oxidative depletion rates of catechins, and excessive production of TRSII (a TRs fraction) and TBs. Analysis of the conversion pathway of polyphenolic compounds during fermentation showed that, during early fermentation, large amounts of catechins were oxidized and converted to TFs and theasinensin B. As fermentation progressed, considerable amounts of theaflavin-3'-gallate, theasinensin A, theaflavin-3-gallate, theaflavin-3,3'-digallate, and theasinensin C were produced and then converted to TRSI; in the final stage, TRSII and TBs were converted continuously. CONCLUSION: Different fermentation temperature and duration combinations directly affected the type and composition of phenolic compounds. The key conditions for controlling phenolic compound conversion and fermentation direction were 60 or 90 min and 25 or 30 °C. Our study provides insights into the regulation of phenolic compound conversion during black tea fermentation. © 2021 Society of Chemical Industry.


Assuntos
Biflavonoides , Camellia sinensis , Catequina , Antioxidantes/análise , Biflavonoides/análise , Camellia sinensis/química , Catequina/análise , Fermentação , Fenol/análise , Chá/química , Temperatura
7.
Arch Anim Nutr ; 73(3): 194-207, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30864858

RESUMO

The present study was conducted to investigate the effects of dietary amylose and amylopectin ratio on growth performance, meat quality, postmortem glycolysis and muscle fibre type transformation of finishing pigs. Twenty-four barrows (Duroc × Landrace × Yorkshire) with an average initial body weight of 61.7 ± 2.01 kg were randomly assigned to four dietary treatments with amylose: amylopectin ratios of 1:1 (HD), 1:2 (MD), 1:3 (CD) and 1:4 (LD). The results showed that the average daily weight gain of finishing pigs tended to reduce with the ratio of amylose and amylopectin decreased (p = 0.09). Diet LD increased the pH24h value and decreased the shear force in longissimus dorsi (LM) compared with diet HD (p < 0.05). Diet LD decreased the lactate content and the HK-2 mRNA abundance and increased the mRNA abundance of ATP5B in LM compared with diet HD (p < 0.05). Higher mRNA abundance of MyHC I and lesser abundance of MyHC IIb in LM were found in pigs fed diet CD and LD than those fed diet HD (p < 0.05). Furthermore, pigs fed diet LD had higher mRNA abundances of PGC-1α and PPAR δ in LM than other groups (p < 0.05). These results suggested that diet with low amylose and amylopectin ratio could improve meat quality of finishing pigs via delaying muscle glycolysis capacity and shifting muscle fibre types.


Assuntos
Amilopectina/metabolismo , Amilose/metabolismo , Glicólise/fisiologia , Carne/análise , Fibras Musculares Esqueléticas/fisiologia , Sus scrofa/fisiologia , Amilopectina/administração & dosagem , Amilose/administração & dosagem , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Dieta/veterinária , Relação Dose-Resposta a Droga , Glicólise/efeitos dos fármacos , Masculino , Fibras Musculares Esqueléticas/efeitos dos fármacos , Distribuição Aleatória , Sus scrofa/crescimento & desenvolvimento
8.
J Mater Sci Mater Med ; 27(5): 92, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26979976

RESUMO

Zein porous scaffolds modified with fatty acids have shown great improvement in mechanical properties and good cell compatibility in vitro, indicating the potential application as a bone tissue engineering substitute. The present study was conducted to systematically investigate whether the addition of fatty acids affects the short-term (up to 12 weeks) and long-term (up to 1 year) behaviors of scaffolds in vivo, mainly focusing on changes in the degradation period and inflammatory responses. Throughout the implantation period, no abnormal signs occurred and zein porous scaffolds modified with oleic acid showed good tolerance in rabbits, characterized by the growth of relatively more blood vessels in the scaffolds and only a slight degree of fibrosis histology. Moreover, the degradation period was prolonged from 8 months to 1 year as compared to the control. These results affirmed further that zein could be used as a new kind of natural biomaterial suitable for bone tissue engineering.


Assuntos
Neovascularização Fisiológica/fisiologia , Ácido Oleico/farmacologia , Ácidos Esteáricos/farmacologia , Alicerces Teciduais , Zeína , Animais , Materiais Biocompatíveis/química , Teste de Materiais , Ácido Oleico/química , Porosidade , Coelhos , Pele , Ácidos Esteáricos/química , Propriedades de Superfície
9.
J Nanosci Nanotechnol ; 15(4): 2634-42, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26353475

RESUMO

Although tumor is one of the most frequently occurring diseases and a leading cause of death, nanotechnology, one of the frontier sciences, is exhibiting its great potential to tumor treatments. The aim of this study was to design a facile and environmentally-friendly method to prepare bovine serum albumin-conjugated heavy metal sulfides nano-materials, including Ag2S, PbS and CdS. Here, bovine serum albumin was introduced in order to direct the synthesis of nano-materials by using its template effect and supply more sites for further modification in future. The crystal structure and morphology were analyzed by XRD and TEM, respectively. Additionally, the antineoplastic activity of nano-materials was compared by cell viability analysis, optical and electron microscopy observation after exposure of the human hepatoma cell line. The results showed that the inhibition effect of heavy metal sulfides on tumor cells was in the order of nano-PbS > bulk CdS > nano-Ag2S > nano-CdS > bulk PbS > bulk Ag2S. It could be concluded that heavy metal sulfides had significantly negative impact on human hepatoma cells growth but it could not be obviously generalized that nano-particles were always more effective to kill tumor cells than bulk materials. The size and surface reactivity might be the important factors causing the difference.


Assuntos
Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Metais Pesados/farmacologia , Nanocompostos/química , Soroalbumina Bovina/química , Sulfetos/farmacologia , Animais , Antineoplásicos/química , Bovinos , Linhagem Celular Tumoral , Humanos , Metais Pesados/química , Semicondutores , Sulfetos/química
10.
Neurosci Biobehav Rev ; 159: 105615, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38437975

RESUMO

The hippocampus is a crucial brain region involved in the process of forming and consolidating memories. Memories are consolidated in the brain through synaptic plasticity, and a key mechanism underlying this process is called long-term potentiation (LTP). Recent research has shown that cholecystokinin (CCK) plays a role in facilitating the formation of LTP, as well as learning and memory consolidation. However, the specific mechanisms by which CCK is involved in hippocampal neuroplasticity and memory formation are complicated or poorly understood. This literature review aims to explore the role of LTP in memory formation, particularly in relation to hippocampal memory, and to discuss the implications of CCK and its receptors in the formation of hippocampal memories. Additionally, we will examine the circuitry of CCK in the hippocampus and propose potential CCK-dependent mechanisms of synaptic plasticity that contribute to memory formation.


Assuntos
Colecistocinina , Hipocampo , Memória , Humanos , Potenciação de Longa Duração , Plasticidade Neuronal
11.
CNS Neurosci Ther ; 30(3): e14422, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37715582

RESUMO

AIMS: Major depressive disorder is a severe psychiatric disorder that afflicts ~17% of the world population. Neuroimaging investigations of depressed patients have consistently reported the dysfunction of the basolateral amygdala in the pathophysiology of depression. However, how the BLA and related circuits are implicated in the pathogenesis of depression is poorly understood. METHODS: Here, we combined fiber photometry, immediate early gene expression (c-fos), optogenetics, chemogenetics, behavioral analysis, and viral tracing techniques to provide multiple lines of evidence of how the BLA neurons mediate depressive-like behavior. RESULTS: We demonstrated that the aversive stimuli elevated the neuronal activity of the excitatory BLA neurons (BLACAMKII neurons). Optogenetic activation of CAMKII neurons facilitates the induction of depressive-like behavior while inhibition of these neurons alleviates the depressive-like behavior. Next, we found that the chemogenetic inhibition of GABAergic neurons in the BLA (BLAGABA ) increased the firing frequency of CAMKII neurons and mediates the depressive-like phenotypes. Finally, through fiber photometry recording and chemogenetic manipulation, we proved that the activation of BLAGABA neurons inhibits BLACAMKII neuronal activity and alleviates depressive-like behavior in the mice. CONCLUSION: Thus, through evaluating BLAGABA and BLACAMKII neurons by distinct interaction, the BLA regulates depressive-like behavior.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Transtorno Depressivo Maior , Humanos , Camundongos , Animais , Complexo Nuclear Basolateral da Amígdala/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Transtorno Depressivo Maior/metabolismo , Neurônios GABAérgicos/metabolismo , Ácido gama-Aminobutírico/metabolismo
12.
Biofactors ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38777339

RESUMO

Cholecystokinin (CCK) plays a key role in various brain functions, including both health and disease states. Despite the extensive research conducted on CCK, there remain several important questions regarding its specific role in the brain. As a result, the existing body of literature on the subject is complex and sometimes conflicting. The primary objective of this review article is to provide a comprehensive overview of recent advancements in understanding the central nervous system role of CCK, with a specific emphasis on elucidating CCK's mechanisms for neuroplasticity, exploring its interactions with other neurotransmitters, and discussing its significant involvement in neurological disorders. Studies demonstrate that CCK mediates both inhibitory long-term potentiation (iLTP) and excitatory long-term potentiation (eLTP) in the brain. Activation of the GPR173 receptor could facilitate iLTP, while the Cholecystokinin B receptor (CCKBR) facilitates eLTP. CCK receptors' expression on different neurons regulates activity, neurotransmitter release, and plasticity, emphasizing CCK's role in modulating brain function. Furthermore, CCK plays a pivotal role in modulating emotional states, Alzheimer's disease, addiction, schizophrenia, and epileptic conditions. Targeting CCK cell types and circuits holds promise as a therapeutic strategy for alleviating these brain disorders.

13.
Food Chem ; 448: 139138, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38569407

RESUMO

Tea cream formed in hot and strong tea infusion while cooling deteriorates quality and health benefits of tea. However, the interactions among temporal contributors during dynamic formation of tea cream are still elusive. Here, by deletional recombination experiments and molecular dynamics simulation, it was found that proteins, caffeine (CAF), and phenolics played a dominant role throughout the cream formation, and the contribution of amino acids was highlighted in the early stage. Furthermore, CAF was prominent due to its extensive binding capacity and the filling complex voids property, and caffeine-theaflavins (TFs) complexation may be the core skeleton of the growing particles in black tea infusion. In addition to TFs, the unidentified phenolic oxidation-derived products (PODP) were confirmed to contribute greatly to the cream formation.


Assuntos
Cafeína , Camellia sinensis , Catequina , Simulação de Dinâmica Molecular , Chá , Chá/química , Cafeína/química , Cafeína/metabolismo , Camellia sinensis/química , Camellia sinensis/metabolismo , Camellia sinensis/crescimento & desenvolvimento , Catequina/química , Catequina/metabolismo , Biflavonoides/química , Biflavonoides/metabolismo , Fenóis/química , Fenóis/metabolismo , Manipulação de Alimentos , Temperatura Alta
14.
Artigo em Inglês | MEDLINE | ID: mdl-38461446

RESUMO

This study proposes a novel inferior vena cava filter (IVCF) design, "Lotus," aiming to enhance release stability and endothelialization. A catheter-filter-vessel model was established for IVCF property analysis, validated by comparing numerical simulations and in vitro tests. Lotus's mechanical properties were analyzed, and optimization suggestions are provided. Compared to existing clinical filters, Lotus demonstrates improved release stability and thrombus capture ability. This work suggests Lotus as a potential technical reference for improved IVCF treatment.

15.
Neuropeptides ; 98: 102322, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36702033

RESUMO

Depression is the second leading cause of disability in the world population, for which currently available pharmacological therapies either have poor efficacy or have some adverse effects. Accumulating evidence from clinical and preclinical studies demonstrates that the amygdala is critically implicated in depressive disorders, though the underlying pathogenesis mechanism needs further investigation. In this literature review, we overviewed depression and the key role of Gamma-aminobutyric acid (GABA) and Glutamate neurotransmission in depression. Notably, we discussed a new cholecystokinin-dependent plastic changes mechanism under stress and a possible antidepressant response of cholecystokinin B receptor (CCKBR) antagonist. Moreover, we discussed the fundamental role of the amygdala in depression, to discuss and understand the pathophysiology of depression and the inclusive role of the amygdala in this devastating disorder.


Assuntos
Depressão , Transtorno Depressivo , Humanos , Ácido gama-Aminobutírico , Transmissão Sináptica , Tonsila do Cerebelo , Colecistocinina/farmacologia , Transtorno Depressivo/tratamento farmacológico
16.
Food Chem X ; 17: 100615, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36974188

RESUMO

Polyphenol oxidation during fermentation plays a critical role in the formation of flavor and function of black tea. However, how the specific structures of tea polyphenols affect their oxidation kinetics during black tea fermentation is still unknown. Here, we found that the oxidations of tea polyphenols, including 7 catechins, 4 phenolic acids and 11 flavonoid glycosides followed pseudo-first-order kinetics during fermentation. Molecular structure and oxygen concentration collaboratively regulated the oxidation rate of different polyphenols. Pyrogallol structure was more easily to be oxidized than catechol and monophenol structure in B-ring, the gallic group in C-ring could inhibit oxidation of catechins, while the role of sugar moiety of flavonoid glycosides was differentiating. In addition, oxygen was found to be the key factor limiting the oxidation rate of polyphenols in regular black tea fermentation, and the oxidation rate constants of tea polyphenols were linearly and positively correlated with oxygen concentration.

17.
Nat Metab ; 5(11): 1986-2001, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37872351

RESUMO

Ammonia has been long recognized as a metabolic waste product with well-known neurotoxic effects. However, little is known about the beneficial function of endogenous ammonia. Here, we show that gut ammonia links microbe nitrogen metabolism to host stress vulnerability by maintaining brain glutamine availability in male mice. Chronic stress decreases blood ammonia levels by altering gut urease-positive microbiota. A representative urease-producing strain, Streptococcus thermophilus, can reverse depression-like behaviours induced by gut microbiota that was altered by stress, whereas pharmacological inhibition of gut ammonia production increases stress vulnerability. Notably, abnormally low blood ammonia levels limit the brain's availability of glutamine, a key metabolite produced by astrocytes that is required for presynaptic γ-aminobutyric acid (GABA) replenishment and confers stress vulnerability through cortical GABAergic dysfunction. Of therapeutic interest, ammonium chloride (NH4Cl), a commonly used expectorant in the clinic, can rescue behavioural abnormalities and GABAergic deficits in mouse models of depression. In sum, ammonia produced by the gut microbiome can help buffer stress in the host, providing a gut-brain signalling basis for emotional behaviour.


Assuntos
Microbioma Gastrointestinal , Camundongos , Masculino , Animais , Microbioma Gastrointestinal/fisiologia , Amônia , Glutamina/metabolismo , Urease/metabolismo , Urease/farmacologia , Astrócitos/metabolismo
18.
Biomater Adv ; 145: 213225, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36527960

RESUMO

Zein is a biocompatible and biodegradable corn protein with promising properties for biomedical applications. It is hydrophobic with the ability to self-assemble in an aqueous medium. It can also form a gel in hydroalcoholic solvents at higher concentrations. Few studies have investigated the biomedical significance of zein gels. Herein, we exploited the injectability and water-responsive increase in stiffness of zein gel to achieve hemostasis by physical blockage of the wound and clot formation. The release of components from the gel further aided blood clotting and gave a higher clot strength than a natural clot, which can prevent rebleeding. Rabbit aortic injury and swine femoral artery injury models were used to evaluate the hemostatic efficacy of the zein gel. Zein gel was effective in both hemostatic models without applying external compression due to an in situ increase in stiffness, while the control (Celox™ Gauze) required external compression at the wound site. The zein gel was easily removed after hemostasis due to hydrophobic self-assembly. Overall, zein gel is proposed as an effective hemostatic product for any wound shape owing to its good shape adaptability and rapid in situ blood-responsive stiffness increase.


Assuntos
Hemostáticos , Zeína , Suínos , Animais , Coelhos , Hemostáticos/farmacologia , Zeína/química , Hemostasia , Géis , Bandagens
19.
Bioact Mater ; 23: 343-352, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36474653

RESUMO

Four-dimensional (4D) printing is a promising technology that provides solutions for compelling needs in various fields. Most of the reported 4D printed systems are based on the temporal shape transformation of printed subjects. Induction of temporal heterogenicity in functions in addition to shape may extend the scope of 4D printing. Herein, we report a 4D printing approach using plant protein (zein) gel inspired by the amyloid fibrils formation mechanism. The printing of zein gel in a specialized layered-Carbopol supporting bath with different water concentrations in an ethanol-water mixture modulates hydrophobic and hydrogen bonding that causes temporal changes in functions. The part of the construct printed in a supporting bath with higher water content exhibits higher drug loading, faster drug release and degradation than those printed in the supporting bath with lower water content. Tri-segment conduit and butterfly-shaped construct with two asymmetrical wings are printed using this system to evaluate biomedical function as nerve conduit and drug delivery system. 4D printed conduits are also effective as a drug-eluting urethral stent in the porcine model. Overall, this study extends the concept of 4D printing beyond shape transformation and presents an approach of fabricating specialized baths for 4D printing that can also be extended to other materials to obtain 4D printed medical devices with translational potential.

20.
Sci Total Environ ; 873: 162438, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36842591

RESUMO

The complication of stent implantation is the biggest obstacle to the success of its clinical application. In this study, we developed a combination way of 3D printing and the coating technique for preparation of functional polyurethane stents against stent implantation-induced thrombosis and postoperative infection. SEM, XPS, static water contact angle, and XRD demonstrated that the functional polyurethane stent had a 37 µm-thickness membrane composed of zein nanospheres (250-350 nm). Meanwhile, ZnO nanoparticles were encapsulated in zein nanospheres while heparin was adsorbed on the surface, causing 97.1 ± 6.4 % release of heparin in 120 min (first-order kinetic model) and 62.7 ± 5.6 % release of Zn2+ in 9 days (Korsmeyer-Peppas model). The mechanical analysis revealed that the functional polyurethane stents had about 8.61 MPa and 2.5 MPa tensile strength and bending strength, respectively. The in vitro biological analysis showed that the functional polyurethane stents had good EA.hy926 cells compatibility (97.9 ± 3.8 %), anti-coagulation response (comparable plasma protein, platelet adhesion and suppressed clotting) and sustained antibacterial activities by comparison with the bare polyurethane stent. The preliminary evaluation by rabbit ex vivo carotid artery intervention experiment demonstrated that the functional polyurethane stents could maintain blood circulation under the continuous stresses of blood flow. Meanwhile, the detailed data from the simulated implant infection experiment in vivo showed the functional polyurethane stents could effectively reduce microbial infection by 3-6 times lower and improve fibrosis and macrophage infiltration.


Assuntos
Nanosferas , Trombose , Zeína , Animais , Coelhos , Poliuretanos , Nanosferas/efeitos adversos , Trombose/etiologia , Heparina/farmacologia , Stents/efeitos adversos
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