RESUMO
Sugars are essential regulatory molecules involved in plant growth and development and defense response. Although the relationship between sugars and disease resistance has been widely discussed, the underlying molecular mechanisms remain unexplored. Ring rot caused by Botryosphaeria dothidea (B. dothidea), which severely affects fruit quality and yield, is a destructive disease of apples (Malus domestica Borkh.). The present study found that the degree of disease resistance in apple fruit was closely related to glucose content. Therefore, the gene encoding a hexokinase, MdHXK1, was isolated from the apple cultivar 'Gala', and characterized during the defense response. Overexpression of MdHXK1 enhanced disease resistance in apple calli, leaves and fruits by increasing the expression levels of genes related to salicylate (SA) synthesis (PHYTOALEXIN DEFICIENT 4, PAD4; PHENYLALANINE AMMONIA-LYASE, PAL; and ENHANCED DISEASE SUSCEPTIBILITY 1, EDS1) and signaling (PR1; PR5; and NONEXPRESSER OF PR GENES 1, NPR1) as well as increasing the superoxide (O2- ) production rate and the hydrogen peroxide (H2 O2 ) content. Overall, the study provides new insights into the MdHXK1-mediated molecular mechanisms by which glucose signaling regulates apple ring rot resistance.
Assuntos
Ascomicetos , Malus , Ascomicetos/fisiologia , Resistência à Doença/genética , Glucose/metabolismo , Malus/genética , Malus/metabolismo , Doenças das Plantas/genéticaRESUMO
The oncogene c-Myc is aberrantly expressed and plays a key role in malignant transformation and progression of hepatocellular carcinoma (HCC). Here, we report that c-Myc is significantly up-regulated by tumor necrosis factor receptor-associated factor 6 (TRAF6), an E3 ubiquitin ligase, in hepatocarcinogenesis. High TRAF6 expression in clinical HCC samples correlates with poor prognosis, and the loss of one copy of the Traf6 gene in Traf6+/- mice significantly impairs liver tumorigenesis. Mechanistically, TRAF6 first interacts with and ubiquitinates histone deacetylase 3 (HDAC3) with K63-linked ubiquitin chains, which leads to the dissociation of HDAC3 from the c-Myc promoter and subsequent acetylation of histone H3 at K9, thereby epigenetically enhancing the mRNA expression of c-Myc. Second, the K63-linked ubiquitination of HDAC3 impairs the HDAC3 interaction with c-Myc and promotes c-Myc protein acetylation, which thereby enhances c-Myc protein stability by inhibiting carboxyl terminus of heat shock cognate 70-kDa-interacting protein-mediated c-Myc ubiquitination and degradation. Importantly, TRAF6/HDAC3/c-Myc signaling is also primed in hepatitis B virus-transgenic mice, unveiling a critical role for a mechanism in inflammation-cancer transition. In clinical specimens, TRAF6 positively correlates with c-Myc at both the mRNA and protein levels, and high TRAF6 and c-Myc expression is associated with an unfavorable prognosis, suggesting that TRAF6 collaborates with c-Myc to promote human hepatocarcinogenesis. Consistently, curbing c-Myc expression by inhibition of TRAF6 activity with a TRAF6 inhibitor peptide or the silencing of c-Myc by small interfering RNA significantly suppressed tumor growth in mice. Conclusion: These findings demonstrate the oncogenic potential of TRAF6 during hepatocarcinogenesis by modulating TRAF6/HDAC3/c-Myc signaling, with potential implications for HCC therapy.
Assuntos
Carcinogênese , Carcinoma Hepatocelular/genética , Genes myc/fisiologia , Histona Desacetilases/fisiologia , Neoplasias Hepáticas/genética , Fator 6 Associado a Receptor de TNF/fisiologia , Animais , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Estabilidade Proteica , Células Tumorais CultivadasRESUMO
The effect of stem cell transplantation in the treatment of neural lesions is so far not satisfactory. Magnetic stimulation is a feasible exogenous interference to improve transplantation outcome. However, the effect of magnetic stimulation on the differentiation of induced pluripotent stem cells (iPSCs) into neuron has not been studied. In this experiment, an in vitro neuron differentiation system from human iPSCs were established and confirmed. Three magnetic stimuli (high frequency [HF], low frequency [LF], intermittent theta-burst stimulation [iTBS]) were applied twice a day during the differentiation process. Immunofluorescence and quantitative polymerase chain reaction (Q-PCR) were performed to analyze the effect of magnetic stimulation. Neural stem cells were obtained on day 12, manifested as floating neurospheres expressing neural precursor markers. All groups can differentiate into neurons while glial cell markers were not detected. Both Immunofluorescence and PCR results showed LF and iTBS increased the transcription and expression of neuronal nuclei (NeuN). HF significantly increased vesicular glutamate transporters2 transcription while iTBS promoted transcription of both synaptophysin and postsynaptic density protein 95. These results indicate that LF and iTBS can promote the generation of mature neurons from human iPSCs; HF may promote differentiate into glutamatergic neurons while iTBS may promote synapse formation during the differentiation.
Assuntos
Diferenciação Celular , Campos Eletromagnéticos , Células-Tronco Pluripotentes Induzidas/citologia , Neurônios/citologia , Transplante de Células-Tronco/métodos , Adulto , Doadores de Sangue , Núcleo Celular/genética , Núcleo Celular/metabolismo , Humanos , Masculino , Células-Tronco Neurais/citologia , Sinapses/metabolismoRESUMO
BACKGROUND & AIMS: Aberrant estrogen receptor-α (ERα) expression and signaling are implicated in the development of hepatocellular carcinoma (HCC), but its regulation in HCC remains enigmatic. Herein, we aimed to identify a new mechanism by which ERα signaling is regulated in HCC, which may lead to a potential new strategy for HCC therapy. METHODS: Expression levels of Erbin and ERα in human HCC samples were evaluated by immunohistochemistry. In vitro and in vivo experiments were used to assess the effect of Erbin and ERα signaling on HCC cell growth. Crosstalk between Erbin and ERα signaling was analyzed by molecular methods. Animal models of diethylnitrosamine (DEN) or DEN/CCl4-induced HCC in wild-type Erbin+/+ and mutant ErbinΔC/ΔC mice were observed. The regulatory effects of Erbin on tamoxifen treatment of HCC were evaluated in vitro and in vivo. RESULTS: Erbin inactivated ERα signaling to drive tumorigenesis of HCC, acting to enhance binding of Chip to ERα via its interaction with ERα and thereby promoting ubiquitination and degradation of ERα. Deletion of the PDZ domain of Erbin in ErbinΔC/ΔC mice, disrupted the interaction of Chip and ERα, increased the stability of ERα protein, and thus inhibited tumorigenesis of HCC. Silencing of Erbin effectively sensitized the response of HCC after tamoxifen treatment in vitro and in vivo. CONCLUSIONS: Our data uncovered an important role of Erbin in regulating HCC tumorigenesis through inactivating ERα-mediated tumor-suppressive signaling, suggesting a new strategy for tamoxifen therapy in HCC by targeting Erbin/ERα signaling axis. LAY SUMMARY: Erbin expression is significantly elevated in human hepatocellular carcinoma (HCC) tissue. This elevated expression of Erbin contributes to tumorigenesis of HCC by negatively regulating ERα signaling. However, restoring ERα signaling by inhibiting Erbin expression enhances the sensitivity of HCC cells to tamoxifen treatment, providing a new approach for tamoxifen treatment in HCC.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/metabolismo , Receptor alfa de Estrogênio/metabolismo , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Antineoplásicos Hormonais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptor alfa de Estrogênio/genética , Feminino , Inativação Gênica , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas Experimentais/etiologia , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Prognóstico , Estabilidade Proteica , Fatores Sexuais , Tamoxifeno/uso terapêutico , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Regulação para CimaRESUMO
Nur77, an immediate-early response gene, participates in a wide range of biological functions. Its human homologue, NUR77, is known by several names and has the HGNC-approved gene symbol NR4A1. However, the role of Nur77 in inflammatory bowel disease (IBD) and its underlying mechanisms remain elusive. Here, using public data from the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC) on the most recent genome-wide association studies (GWAS) for ulcerative colitis (UC) and Crohn's disease (CD), we found that genetic variants of the NUR77 gene are associated with increased risk for both UC and CD. Accordingly, Nur77 expression was significantly reduced in colon tissues from patients with UC or CD and mice treated with DSS. Nur77 deficiency increased the susceptibility of mice to DSS-induced experimental colitis and prevented intestinal recovery, whereas treatment with cytosporone B (Csn-B), an agonist for Nur77, significantly attenuated excessive inflammatory response in the DSS-induced colitis mouse model. Mechanistically, NUR77 acts as a negative regulator of TLR-IL-1R signalling by interacting with TRAF6. This interaction prevented auto-ubiquitination and oligomerization of TRAF6 and subsequently inhibited NF-κB activation and pro-inflammatory cytokine production. Taken together, our GWAS-based analysis and in vitro and in vivo studies have demonstrated that Nur77 is an important regulator of TRAF6/TLR-IL-1R-initiated inflammatory signalling, and loss of Nur77 may contribute to the development of IBD, suggesting Nur77 as a potential target for the prevention and treatment of IBD.
Assuntos
Colite Ulcerativa/genética , Doença de Crohn/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Receptores de Interleucina-1/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Receptores Toll-Like/metabolismo , Adulto , Idoso , Animais , Colo/metabolismo , Sulfato de Dextrana/farmacologia , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/antagonistas & inibidores , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/deficiência , Fenilacetatos/farmacologia , Estudos Prospectivos , Transdução de Sinais/fisiologiaRESUMO
To investigate the effects of aerobic exercise and starvation on growth performance, postprandial metabolic response and their interaction in a sedentary fish species, either satiation-fed or starved juvenile southern catfish (Silurus meridionalis) were exercised at 25 °C under three water velocities, i.e., nearly still water (control), 1 body length (bl) s(-1) and 2 bl s(-1), for eight weeks. Then, the feed intake (FI), food conversion efficiency (FCE), specific growth rate (SGR), morphological parameters, resting MO2 (MO2rest) and postprandial MO2 responses of the experimental fish were measured. Exercise at a low velocity (1 bl s(-1)) showed no effect on any growth performance parameter, whereas exercise at a high velocity (2 bl s(-1)) exhibited higher FI but similar SGR due to the extra energy expenditure from swimming and consequent decreased FCE. Starvation led to a significant body mass loss, whereas the effect intensified in both exercise groups. Exercise resulted in improved cardio-respiratory capacity, as indicated by increased gill and heart indexes, whereas it exhibited no effect on resting and postprandial metabolism in S. meridionalis. The starved fish displayed significantly larger heart, gill and digestive tract indexes compared with the feeding fish, suggesting selective maintenance of cardio-respiratory and digestive function in this fish species during starvation. However, starved fish still exhibited impaired digestive performance, as evidenced by the prolonged duration and low postprandial metabolic increase, and this effect was further exacerbated in both the 1 and 2 bl s(-1) exercise groups. These data suggest the following: (1) aerobic exercise produced no improvement in growth performance but may have led to the impairment of growth under insufficient food conditions; (2) the mass of different organs and tissues responded differently to aerobic exercise and starvation due to the different physiological roles they play; and (3) aerobic exercise had no effect on the postprandial metabolic response under a "normal feeding" situation, whereas it may have resulted in the impairment of the digestive capacity when food availability was low due to the competition of energy and oxygen under unfavorable conditions in juvenile S. meridionalis.
Assuntos
Peixes-Gato/fisiologia , Condicionamento Físico Animal/fisiologia , Período Pós-Prandial/fisiologia , Inanição/fisiopatologia , Animais , Peixes-Gato/metabolismo , Digestão/fisiologia , Metabolismo Energético/fisiologia , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/patologia , Oxigênio/metabolismo , Consumo de Oxigênio , Inanição/metabolismo , Natação/fisiologiaRESUMO
We investigated the effects of starvation and re-feeding on growth and swimming performance and their relationship in juvenile black carp (Mylopharyngodon piceus). We measured the specific growth rate (SGR), resting metabolic rate (RMR) and constant acceleration test speed (U CAT, the maximum swimming speed at exhaustion by constant acceleration test with 0.1667 cm s(-2) rate) in a treatment group (21 days of starvation then 21 days of re-feeding) and control group (routine feeding) (n = 20). Starvation resulted in a 17 % decrease in body mass of black carp (P < 0.05). After 21 days of re-feeding, body mass was greater than that of pre-starvation but still less than that of the control group at 42 days. During the re-feeding phase, the SGR of the treatment group was higher than that of the control group (P < 0.05). Starvation resulted in a significant decrease in the RMR and U CAT. After 21 days of re-feeding, both the RMR and U CAT recovered to the pre-starvation levels. In the control group, individual juvenile black carp displayed strong repeatability of the RMR and U CAT across the measurement periods (P ≤ 0.002). In the treatment group, RMR showed significant repeatability between pre-starvation and re-feeding (P = 0.007), but not between pre-starvation and starvation or between starvation and re-feeding. U CAT showed significant repeatability between pre-starvation and starvation (P = 0.006) and between pre-starvation and re-feeding (P = 0.001), but not between starvation and re-feeding. No correlation or only a weak correlation was found between any two variables of RMR, U CAT and SGR, whereas the increment of the U CAT (ΔU CAT) was negatively correlated with that of SGR during the starvation phase (r = -0.581, n = 20, P = 0.007) and re-feeding phase (r = -0.568, n = 20, P = 0.009). This suggested that within individual black carp, there is a trade-off between growth and maintenance (or development) of swimming performance under food-limited conditions.
Assuntos
Carpas , Inanição/fisiopatologia , Animais , Carpas/crescimento & desenvolvimento , Carpas/metabolismo , Carpas/fisiologia , Ingestão de Alimentos , Oxigênio/metabolismo , Inanição/metabolismo , NataçãoRESUMO
Nur77, an orphan member of the nuclear receptor superfamily, has been implicated in tumorigenesis. However, its contributions to colorectal cancer (CRC) invasion and metastasis are largely under characterized. Here, we present the first evidence that the invasion and metastasis of CRC is regulated by Nur77. High expression of Nur77 was observed in clinical CRC tissues, and this elevated expression was significantly associated with advanced tumor, lymph nodes, distant metastasis stage (P = 0.003), lymph node metastasis (P = 0.001) and poor survival (P = 0.03). Overexpression of Nur77 in CRC cells enhanced cell invasion in vitro, whereas knockdown of Nur77 diminished cell invasion and metastasis both in vitro and in vivo. In studying the possible mechanism by which overexpression of Nur77 contributes to CRC invasion and metastasis, we observed that the nuclear protein Nur77 promoted the expression of matrix metalloproteinase (MMP)-9, a novel downstream target of Nur77, and subsequently decreased the expression of E-cadherin. Examination of clinical samples further showed that Nur77 expression is positively correlated with MMP-9, whereas negatively correlated with E-cadherin. Interestingly, Nur77-mediated CRC invasion via MMP-9 and E-cadherin could be mimicked by some metastasis-inducible factors including hypoxia and prostaglandin E2. Collectively, our study demonstrated that Nur77 could promote the invasion and metastasis of CRC cells through regulation of MMP-9/E-cadherin signaling. These observations provide a possible new strategy for potentially treating or preventing the metastasis of CRC through targeting of Nur77.
Assuntos
Caderinas/biossíntese , Carcinogênese/genética , Neoplasias Colorretais/genética , Metaloproteinase 9 da Matriz/biossíntese , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Caderinas/genética , Movimento Celular/genética , Neoplasias Colorretais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Humanos , Masculino , Metaloproteinase 9 da Matriz/genética , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Metástase Neoplásica , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Transdução de Sinais/genéticaRESUMO
Dysregulation of cholesterol homeostasis is implicated in the development and progression of hepatocellular carcinoma (HCC) that is characterized by intrahepatic and early extrahepatic metastases. A better understanding of the underlying mechanisms regulating cholesterol metabolism in HCC could help identify strategies to circumvent the aggressive phenotype. Here, we found that high expression of intracellular SPARC (secreted protein acidic and rich in cysteine) was significantly associated with elevated cholesterol levels and an enhanced invasive phenotype in HCC. SPARC potentiated cholesterol accumulation in HCC cells during tumor progression by stabilizing the ApoE protein. Mechanistically, SPARC competitively bound to ApoE, impairing its interaction with the E3 ligase tripartite motif containing 21 (TRIM21) and preventing its ubiquitylation and subsequent degradation. ApoE accumulation led to cholesterol enrichment in HCC cells, stimulating PI3K-AKT signaling and inducing epithelial-mesenchymal transition (EMT). Importantly, sorafenib-resistant HCC cells were characterized by increased expression of intracellular SPARC, elevated cholesterol levels, and enhanced invasive capacity. Inhibiting SPARC expression or reducing cholesterol levels enhanced the sensitivity of HCC cells to sorafenib treatment. Together, these findings unveil interplay between SPARC and cholesterol homeostasis. Targeting SPARC-triggered cholesterol-dependent oncogenic signaling is a potential therapeutic strategy for advanced HCC. SIGNIFICANCE: Intracellular SPARC boosts cholesterol availability to fuel invasion and drug resistance in hepatocellular carcinoma, providing a rational approach to improve the treatment of advanced liver cancer.
Assuntos
Apolipoproteínas E , Carcinoma Hepatocelular , Colesterol , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas , Invasividade Neoplásica , Osteonectina , Sorafenibe , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Osteonectina/metabolismo , Osteonectina/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Humanos , Sorafenibe/farmacologia , Colesterol/metabolismo , Animais , Camundongos , Apolipoproteínas E/metabolismo , Apolipoproteínas E/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Linhagem Celular Tumoral , Camundongos Nus , Masculino , Ensaios Antitumorais Modelo de Xenoenxerto , Antineoplásicos/farmacologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Macrophages are phenotypically and functionally diverse in the tumor microenvironment (TME). However, how to remodel macrophages with a protumor phenotype and how to manipulate them for therapeutic purposes remain to be explored. Here, we show that in the TME, RARγ is downregulated in macrophages, and its expression correlates with poor prognosis in patients with colorectal cancer (CRC). In macrophages, RARγ interacts with tumor necrosis factor receptor-associated factor 6 (TRAF6), which prevents TRAF6 oligomerization and autoubiquitination, leading to inhibition of nuclear factor κB signaling. However, tumor-derived lactate fuels H3K18 lactylation to prohibit RARγ gene transcription in macrophages, consequently enhancing interleukin-6 (IL-6) levels in the TME and endowing macrophages with tumor-promoting functions via activation of signal transducer and activator of transcription 3 (STAT3) signaling in CRC cells. We identified that nordihydroguaiaretic acid (NDGA) exerts effective antitumor action by directly binding to RARγ to inhibit TRAF6-IL-6-STAT3 signaling. This study unravels lactate-driven macrophage function remodeling by inhibition of RARγ expression and highlights NDGA as a candidate compound for treating CRC.
Assuntos
Neoplasias Colorretais , Interleucina-6 , Humanos , Carcinogênese/metabolismo , Transformação Celular Neoplásica/metabolismo , Neoplasias Colorretais/patologia , Histonas/metabolismo , Interleucina-6/metabolismo , Lactatos/metabolismo , Macrófagos/metabolismo , Fator de Transcrição STAT3/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Microambiente TumoralRESUMO
Continual swimming exercise usually promotes growth in fish at a moderate water velocity. We hypothesized that the improvement in growth in exercise-trained fish may be accompanied by increases in digestive enzyme activity, respiratory capacity and, hence, postprandial metabolism. Juvenile qingbo fish (Spinibarbus sinensis) were subjected to aerobic training for 8weeks at a water velocity of control (3cms(-1)), 1, 2 and 4 body length (bl)s(-1) at a constant temperature of 25°C. The feed intake (FI), food conversion rate (FCR), specific growth rate (SGR), whole-body composition, trypsin and lipase activities, maximal oxygen consumption (MËO2max) and postprandial MËO2 response were measured at the end of the training period. Aerobic exercise training induced a significant increase in FI compared with the control group, while the FCR of the 4bls(-1) group was significantly lower than for the other three groups (P<0.05). The 1 and 2bls(-1) groups showed a significantly higher SGR over the control group (P<0.05). The whole-body fat and protein contents were significantly altered after aerobic exercise training (P<0.05). Furthermore, aerobic exercise training elevated the activity of both trypsin and lipase in the hepatopancreas and intestinal tract of juvenile S. sinensis. The MËO2max of the 4bls(-1) training group was significantly higher than for the control group. The resting MËO2 (MËO2rest) and peak postprandial MËO2 (MËO2peak) in the three training groups were significantly higher than in the control group (P<0.05). Time to MËO2peak was significantly shorter in the 1, 2 and 4bls(-1) training groups compared with the control group, while exercise training showed no effect on SDA (specific dynamic action) duration, factorial metabolic scope, energy expended on SDA and the SDA coefficient when compared to the control group. These data suggest that (1) the optimum water velocity for the growth of juvenile S. sinensis occurred at approximately 2.4bls(-1); (2) the improvement of growth may have been primarily due to an increase in the FI after long-term training; (3) and aerobic exercise training boosted the activity of digestive enzymes and maximum digestive metabolism, which could favor fast digestion and growth in juvenile S. sinensis.
Assuntos
Digestão/fisiologia , Peixes/crescimento & desenvolvimento , Peixes/metabolismo , Lipase/metabolismo , Condicionamento Físico Animal , Período Pós-Prandial , Tripsina/metabolismo , Aerobiose , Animais , Composição Corporal , Comportamento Alimentar/fisiologia , Consumo de Oxigênio/fisiologiaRESUMO
We examined the antifungal characteristics of linalool against Botrytis cinerea using plate inhibition assay and spore germination assay, and assessed the capacity of linalool in controlling tomato gray mold disease via tomato pot inoculation assay. The results showed that linalool exhibited strong inhibitive effects on mycelial growth of B. cinerea, with an EC50 value of 0.581 mL·L-1. In the spore germination test, linalool treatment inhibited spore germination in a dose-dependent manner. The electric conductivity and the malondialdehyde (MDA) contents were significantly increased in linalool-treated B. cinerea than that of the control, indicating that linalool induced oxidative damage and destroyed the cell membrane integrity in B. cinerea. The activities of the superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) in the linalool-treated B. cinerea were decreased significantly by 27.4%, 68.9% and 26.0%, respectively, suggesting that linalool inhibited the antioxidant activity of B. cinerea. In the pot experiment, the diameter of lesions in linalool-treated tomatoes was significantly smaller than that of the control. The activities of SOD, POD, CAT, polyphenol oxidase, and phenylalnine ammonialyase in the linalool-treated tomatoes increased, while the MDA content decreased, suggesting that linalool could alleviate the oxidative damage caused by B. cinerea and promote plant disease resistance. In summary, linalool had inhibitory effect on the growth of B. cinerea and could control gray mold disease in tomatoes. These findings could lay the foundation for developing bota-nical antifungal agents for management of tomato gray mold disease.
Assuntos
Solanum lycopersicum , Botrytis , Superóxido Dismutase , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologiaRESUMO
The size and functional capacity of the gastrointestinal (GI) tract and associated organs vary in response to environmental cues. The GI tract and associated organs are also very metabolically active in animals. Hence, animals may reduce the size and function of their GI tract to conserve energy when deprived of food. The main aims of this study were to investigate how Silurus meridionalis regulates the function and structure of its GI tract and associated organs during starvation. Starvation induced a decrease in both maintenance metabolism (MO(2rest), decreased by approximately 50%) and respiratory frequency (indicated by double side gill activity and notated as f(R), decreased by 29%). Lipase, trypsin and aminopeptidase-A showed a similar reduction in mass-specific activities during starvation, but pepsin and α-amylase did not. The starvation of experimental fish resulted in a significant reduction in body weight, the wet mass of the liver and the digestive-somatic system, the hepato-somatic index and the condition factor whereas the wet masses of the GI tract, pancreas, gall bladder and the relative intestinal length did not vary significantly during starvation. The reduction in liver wet mass was the main reason for the decrease in the wet mass of digestive-somatic system in this species. Only the mucosal area of the PI was affected significantly by starvation, decreasing by 34% at the end of the experiment. S. meridionalis displayed a decreasing intestinal mucosal area towards the distal intestine, and this gradient was not affected by starvation. The morphology and structure of both the GI tract and the liver were greatly down-regulated, as indicated by decreases in liver cell size, the mucosal thickness of the stomach and intestine, the density of goblet cells and microvilli surface area (MVSA), implying that food deprivation greatly impaired the digestive and absorptive functions of the GI tract in S. meridionalis. When deprived of food, S. meridionalis can endure harsh periods of starvation and adaptively down-regulate the function and structure of the digestive tract with physiological and biochemical strategies.
Assuntos
Peixes-Gato/fisiologia , Sistema Digestório/fisiopatologia , Trato Gastrointestinal/fisiologia , Inanição/fisiopatologia , Animais , Peso Corporal/fisiologia , Peixes-Gato/metabolismo , Sistema Digestório/enzimologia , Sistema Digestório/metabolismo , Regulação para Baixo/fisiologia , Feminino , Trato Gastrointestinal/enzimologia , Trato Gastrointestinal/metabolismo , Glutamil Aminopeptidase/metabolismo , Mucosa Intestinal/enzimologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/fisiologia , Lipase/metabolismo , Microvilosidades/enzimologia , Microvilosidades/metabolismo , Microvilosidades/fisiologia , Tamanho do Órgão/fisiologia , Inanição/metabolismo , Tripsina/metabolismo , alfa-Amilases/metabolismoRESUMO
Ethylene-mediated leaf senescence and the compromise of photosynthesis are closely associated but the underlying molecular mechanism is a mystery. Here we reported that apple DEHYDRATASE-ENOLASE-PHOSPHATASE-COMPLEX1 (MdDEP1), initially characterized to its enzymatic function in the recycling of the ethylene precursor SAM, plays a role in the regulation of photosystem I (PSI) activity, activating reactive oxygen species (ROS) homeostasis, and negatively regulating the leaf senescence. A series of Y2H, Pull-down, CO-IP and Cell-free degradation biochemical assays showed that MdDEP1 directly interacts with and dephosphorylates the nucleus-encoded thylakoid protein MdY3IP1, leading to the destabilization of MdY3IP1, reduction of the PSI activity, and the overproduction of ROS in plant cells. These findings elucidate a novel mechanism that the two pathways intersect at MdDEP1 due to its moonlighting role in destabilizing MdY3IP1, and synchronize ethylene-mediated leaf senescence and the compromise of photosynthesis.
RESUMO
BACKGROUND: TRIP6 is a zyxin family member that serves as an adaptor protein to regulate diverse biological processes. In prior reports, TRIP6 was shown to play a role in regulating inflammation. However, its in vivo roles and mechanistic importance in colitis remain largely elusive. Herein, we therefore employed TRIP6-deficient (TRIP6-/-) mice in order to explore the mechanistic importance of TRIP6 in a dextran sodium sulfate (DSS)-induced model of murine colitis. FINDINGS: Wild-type (TRIP6+/+) mice developed more severe colitis following DSS-mediated disease induction relative to TRIP6-/- mice, as evidenced by more severe colonic inflammation and associated crypt damage. TRIP6 expression in wild-type mice was significantly elevated following DSS treatment. Mechanistically, TRIP6 binds to TRAF6 and enhances oligomerization and autoubiquitination of TRAF6. This leads to the activation of NF-κB signaling and the expression of pro-inflammatory cytokines such as TNFα and IL-6, in the in vivo mouse model of colitis. CONCLUSIONS: These in vivo data demonstrate that TRIP6 serves as a positive regulator of DSS-induced colitis through interactions with TRAF6 resulting in the activation of inflammatory TRAF6 signaling, highlighting its therapeutic promise as a protein that theoretically can be targeted to prevent or treat colitis.
RESUMO
The Chinese giant salamander (Andrias davidianus), one of the largest extant amphibian species, has dramatically declined in the wild. As an ectotherm, it may be further threatened by climate change. Therefore, understanding the thermal physiology of this species should be the priority to formulate related conservation strategies. In this study, the plasticity in metabolic rate and thermal tolerance limits of A. davidianus larvae were studied. Specifically, the larvae were acclimated to three temperature levels (7 °C, cold stress; 15 °C, optimum; and 25 °C, heat stress) and two diet items (red worm or fish fray) for 20 days. Our results indicated that cold-acclimated larvae showed increased metabolic capacity, while warm-acclimated larvae showed a decrease in metabolic capacity. These results suggested the existence of thermal compensation. Moreover, the thermal tolerance windows of cold-acclimated and warm-acclimated larvae shifted to cooler and hotter ranges, respectively. Metabolic capacity is not affected by diet but fish-fed larvae showed superiority in both cold and heat tolerance, potentially due to the input of greater nutrient loads. Overall, our results suggested a plastic thermal tolerance of A. davidianus in response to temperature and diet variations. These results are meaningful in guiding the conservation of this species.
RESUMO
BACKGROUND: Endometrial lesions include endometrial cancer and inferior fibroids. Among them, endometrial cancer as a malignant tumor seriously endangers the life and health of patients. Ultrasonography is an important means of diagnosing female reproductive system diseases, and it is of critical value for the early diagnosis of endometrial cancer. However, different ultrasound inspection programs have achieved different results. It is of great significance to choose a suitable inspection program. AIM: To explore the diagnostic efficacy of different ultrasonic examination methods in clinical endometrial lesions. METHODS: The 140 patients with endometrial lesions who were treated in our hospital from April 2018 to October 2019 were used as the research subjects. All patients underwent transvaginal color ultrasound and transabdominal color ultrasound. We compared the diagnostic coincidence and image display effects of the two different examination methods, and the endometrial thickness, blood flow, uterine effusion and resistance index of different diseases were observed by transvaginal color ultrasound. RESULTS: The diagnostic coincidence rate of all types of diseases of transvaginal color ultrasound was significantly higher than that of transabdominal color ultrasound (P = 0.001, 0.005, 0.001 and 0.001). In addition, the excellent and good rate of image display of transvaginal color ultrasound was higher than that of transabdominal color ultrasound (P = 0.001). There were significant differences in endometrial thickness in patients with different types of endometrial lesions through the transvaginal color examination (P = 0.001). The incidence rate of uterine effusion in patients with endometrial carcinoma was significantly higher than that in patients with other types of endometrial lesions (P = 0.001), and the rate of the blood flow was the highest (P = 0.001). The comparison of blood flow resistance index indicated that the blood flow resistance index in endometrial cancer patients was the lowest, which shows that the difference was statistically significant (P = 0.001). CONCLUSION: The overall diagnostic efficacy of transvaginal color ultrasound in the clinical diagnosis of endometrial lesions is better than that of transabdominal color ultrasound, which held higher diagnostic coincidence rate and image display effect. There were significant differences in the thickness of the endometrium and the blood flow in different types of lesions.
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To examine the effects of exercise training on the metabolic interaction between digestion and locomotion in juvenile darkbarbel catfish (Peltebagrus vachelli) (5.58+/-0.04 g), the postprandial metabolic response, critical swimming speeds (U(crit)) and oxygen consumption rates (VO(2)) during swimming were measured on fish held at a constant temperature (25 degrees C). Fish were fed a diet of cutlets of freshly killed loach. Fish in the trained group were forced to swim at 60% U(crit) for 50 min followed by an exhaustive 10-min chase once daily for 21 days. Exercise training did not produce significant differences in resting VO(2) (VO(2rest)) and postprandial peak VO(2) (VO(2peak)) compared to the non-trained groups. However, exercise training elicited a significant decrease in both the duration and energy expenditure of digestion when fed with similar food (P<0.05). Feeding had no significant effect on U(crit) of non-trained fish, while it caused a significantly lower U(crit) (compared to fasting fish) in trained fish (P<0.05). Training resulted in a significantly higher U(crit) and active VO(2) (VO(2active)) in fasting fish when fish swam at U(crit). However, training had no effect on either the U(crit) or VO(2active) of post-feeding fish. Our results suggest that: (1) the central cardio-respiratory systems of non-trained darkbarbel catfish can support the oxygen demands of both digestion and the locomotion simultaneously; (2) the metabolic mode of competition in darkbarbel catfish is flexible; it changed from an additive model to a digestion-priority model after exercise training; (3) training may be accounted for cardio-respiratory capacity increase and following improvement of swimming performance during fasting in darkbarbel catfish, although, the swimming capacity was sacrificed to digestion in the situation of postprandial locomotion.
Assuntos
Peixes-Gato/fisiologia , Animais , Peixes-Gato/metabolismo , Digestão/fisiologia , Ingestão de Alimentos/fisiologia , Jejum/fisiologia , Consumo de Oxigênio , Condicionamento Físico Animal/fisiologia , Esforço Físico/fisiologia , Período Pós-Prandial/fisiologia , Natação/fisiologiaRESUMO
BACKGROUND: Toxoplasma gondii (T. gondii) is an obligate intracellular parasite, which can affect the pregnancy outcomes in infected females by damaging the uterus, and the intrauterine environment as well as and the hypothalamus resulting in hormonal imbalance. However, the molecular mechanisms underlying the parasite-induced poor pregnancy outcomes and the key genes regulating these mechanisms remain unclear. Therefore, this study aimed to analyze the gene expression in the mouse's uterus following experimentally-induced acute infection with T. gondii RH strain. Three groups of female mice were intraperitoneally injected with tachyzoites as follow; 3 days before pregnancy (FBD6), after pregnancy (FAD6), and after implantation (FID8) as the experimental groups. Another corresponding three groups served as control, were injected with normal saline at the same time. Transcriptome analysis of the total RNA extracted from both infected and non-infected mouse uterus samples was performed using RNA sequencing (RNA-Seq). RESULTS: The three experimental groups (FBD6, FAD6, and FID8) had a total of 4,561, 2,345, and 2,997 differentially expressed genes (DEGs) compared to the controls. The significantly upregulated and downregulated DEGs were 2,571 and 1,990 genes in FBD6, 1,042 and 1,303 genes in FAD6 and 1,162 and 1,835 genes in FID8 group, respectively. The analysis of GO annotation, and KEGG pathway showed that DEGs were mainly involved in anatomical structure development, transport, cell differentiation, embryo development, hormone biosynthetic process, signal transduction, immune system process, phagosome, pathways in cancer, and cytokine-cytokine receptor interaction pathways. CONCLUSION: T. gondii infection can induce global transcriptomic changes in the uterus that may cause pregnancy hypertension, destruct the intrauterine environment, and hinder the normal development of placenta and embryo. Our results may help to understand the molecular mechanisms of the acute T. gondii infection, which could promote the development of new therapeutics or prophylactics for toxoplasmosis in pregnancy.
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Temperature is one of the most important environmental factors affecting the physiological activities and, thus, the fitness of fish, and physiological studies can help predict the effects of climate change on fish species in the field. The aim of this study was to investigate the effect of acclimation temperature on the thermal tolerance, hypoxia tolerance and swimming ability of two endangered fish species in the upper reach of the Yangtze River, namely, the Chinese sucker (Myxocyprinus asiaticus) and rock carp (Procypris rabaudi). The fish were acclimated at either 15 °C or 25 °C for a 3-week period. Then, thermal tolerance as indicated by the critical thermal maximum (CTmax) and critical thermal minimum (CTmin), hypoxia tolerance as indicated by the aquatic surface respiration (ASR50) and loss of equilibrium (LOE50), swimming performance as indicated by the critical swimming speed (Ucrit), aerobic capacity as indicated by the maximum metabolic rate and aerobic scope were measured. As expected, the thermal indicators of both species increased with temperature, and their values at both acclimation temperatures were similar to those of fish living in the Yangtze River. However, both species showed poor hypoxia tolerance compared to most fish species in the Yangtze River, according to previous studies. In particular, Chinese sucker acclimated at a low temperature exhibited an unusually strong decrease in hypoxia tolerance with decreasing temperature (fish usually showed high hypoxia tolerance due to decreased oxygen demand and high environmental oxygen tension at low temperature). Furthermore, Chinese sucker exhibited poorer swimming performance than rock carp (which is also a relatively poor swimmer among the fish species in the Yangtze River) when maintained at a high temperature due to low swimming efficiency, possibly as a consequence of its deep body shape. The difference in Ucrit was magnified at low temperature due to the more profound decrease in metabolic scope in Chinese sucker than in rock carp (55% vs 20%), but Chinese sucker showed a higher resting metabolic rate than rock carp at a low temperature, which is difficult to explain. This result suggested that low hypoxia tolerance and poor swimming performance due to the low cardiorespiratory capacity and (or) non-streamlined body shape of both fish species, especially Chinese sucker, reared at low temperature might be two of the reasons why they are not well adjusted to the change in their natural habitat and have thus declined in recent decades. The underlying physiological and biochemical mechanisms involved in the unusual adjustment of the physiological function of Chinese sucker and its ecological relevance must be investigated further. The present study provides a good example of a physiological investigation yielding very interesting and useful data for species conservation in a changing world.