RESUMO
Three dsRNA segments were detected in Fusarium pseudograminearum strain CF14029, a pathogen causing Fusarium crown rot in China. Characterization and sequence analysis confirmed that these dsRNA sequences originated from the same virus. The viral genome consists of three dsRNA segments: dsRNA1 (3,560 nt in length), encoding an RNA-dependent RNA polymerase (RdRp), dsRNA2 (2,544 nt in length), encoding a hypothetical protein, and dsRNA3 (2,478 nt in length), encoding a putative coat protein (CP). Phylogenetic analysis based on the RdRp and CP amino acid sequences revealed a high degree of similarity of this virus to members of the genus Alternavirus, family Alternaviridae, isolated from other Fusarium fungi. As a novel member of the genus Alternavirus, this virus was provisionally named "Fusarium pseudograminearum alternavirus 1" (FpgAV1). Like other alternaviruses found in Fusarium species, the positive-sense strand of each genomic dsRNA of FpgAV1 possesses a poly(A) tail and a distinctive 5'-terminal octamer sequence (5'-GCT GTG TG-3'). This is the first report of the genomic sequence of an alternavirus identified in F. pseudograminearum.
Assuntos
Fusarium , Fusarium/genética , Triticum/microbiologia , Filogenia , Genoma Viral , RNA de Cadeia Dupla/genética , RNA Polimerase Dependente de RNA/genética , Doenças das Plantas/microbiologiaRESUMO
In this study, a series of BiTeX (X = Cl, Br, I) photocatalysts were successfully synthesized via a simple hydrothermal method. The synthesis process involved dissolving BiX3 and Te powder in toluene to identify the most efficient material for photocatalytic activity. The main objective of this approach is to facilitate the conversion of carbon dioxide into sustainable solar fuels, such as alcohols and hydrocarbons, offering an appealing solution to address environmental concerns and energy crises. The BiTeX photocatalysts demonstrated significant proficiency in converting CO2 into CH4, particularly BiTeCl exhibited a notable photocatalytic conversion rate of up to 0.51 µmolg-1h-1. The optimized BiTeX photocatalysts displayed a gradual and selective transition from CO2 to CH4, ultimately producing valuable hydrocarbons (C2+). Furthermore, owing to their ability to reduce CO2, these photocatalysts show promise as materials for mitigating environmental pollution.
Assuntos
Dióxido de Carbono , Luz , Dióxido de Carbono/química , CatáliseRESUMO
Numerous antibiotic resistance genes (ARGs) and virulence factors (VFs) found in animal manure pose significant risks to human health. However, the effects of graphene sodium selenite (GSSe), a novel chemical nano-Selenium, and biological nano-Selenium (BNSSe), a new bioaugmentation nano-Se, on bacterial Se metabolism, chemotaxis, ARGs, and VFs in animal manure remain unknown. In this study, we investigated the effects of GSSe and BNSSe on ARGs and VFs expression in broiler manure using high-throughput sequencing. Results showed that BNSSe reduced Se pressure during anaerobic fermentation by inhibiting bacterial selenocompound metabolism pathways, thereby lowering manure Selenium pollution. Additionally, the expression levels of ARGs and VFs were lower in the BNSSe group compared to the Sodium Selenite and GSSe groups, as BNSSe inhibited bacterial chemotaxis pathways. Co-occurrence network analysis identified ARGs and VFs within the following phyla Bacteroidetes (genera Butyricimonas, Odoribacter, Paraprevotella, and Rikenella), Firmicutes (genera Lactobacillus, Candidatus_Borkfalkia, Merdimonas, Oscillibacter, Intestinimonas, and Megamonas), and Proteobacteria (genera Desulfovibrio). The expression and abundance of ARGs and VFs genes were found to be associated with ARGs-VFs coexistence. Moreover, BNSSe disruption of bacterial selenocompound metabolism and chemotaxis pathways resulted in less frequent transfer of ARGs and VFs. These findings indicate that BNSSe can reduce ARGs and VFs expression in animal manure by suppressing bacterial selenocompound metabolism and chemotaxis pathways.
Assuntos
Selênio , Humanos , Animais , Selênio/farmacologia , Esterco/análise , Genes Bacterianos , Antibacterianos/farmacologia , Quimiotaxia/genética , Selenito de Sódio/farmacologia , Galinhas/genética , Bactérias , Resistência Microbiana a Medicamentos/genética , Bacteroidetes , FirmicutesRESUMO
A novel positive-sense single-stranded RNA mycovirus, designated as "Magnaporthe oryzae botourmiavirus 10" (MoBV10), was identified in the rice blast fungus Magnaporthe oryzae isolate HF04. MoBV10 has a single genomic RNA segment consisting of 2,448 nucleotides, which contains a single open reading frame encoding an RNA-dependent RNA polymerase. Genome comparison and phylogenetic analysis indicated that MoBV10 is a new member of the genus Betascleroulivirus in the family Botourmiaviridae. The 5'- and 3'-terminal sequences of the genomic RNA of MoBV10 have inverted complementarity and potentially form a panhandle structure, which is very rare in RNA viruses.
Assuntos
Magnaporthe , Oryza , Vírus de RNA , Ascomicetos , Genoma Viral , Magnaporthe/genética , Oryza/microbiologia , Filogenia , Doenças das Plantas/microbiologia , RNA Viral/genéticaRESUMO
Deep reinforcement learning provides a new approach to solving complex signal optimization problems at intersections. Earlier studies were limited to traditional traffic detection techniques, and the obtained traffic information was not accurate. With the advanced in technology, we can obtain highly accurate information on the traffic states by advanced detector technology. This provides an accurate source of data for deep reinforcement learning. There are many intersections in the urban network. To successfully apply deep reinforcement learning in a situation closer to reality, we need to consider the problem of extending the knowledge gained from the training to new scenarios. This study used advanced sensor technology as a data source to explore the variation pattern of state space under different traffic scenarios. It analyzes the relationship between the traffic demand and the actual traffic states. The model learned more from a more comprehensive state space of traffic. This model was successful applied to new traffic scenarios without additional training. Compared our proposed model with the popular SAC signal control model, the result shows that the average delay of the DQN model is 5.13 s and the SAC model is 6.52 s. Therefore, our model exhibits better control performance.
Assuntos
Aclimatação , Reforço Psicológico , Armazenamento e Recuperação da Informação , AprendizagemRESUMO
The recycling of lithium batteries should be prioritized, and the use of discarded alkali metal battery electrode materials as photocatalysts merits research attention. This study synthesized alkali metal cobalt oxide (MCoO2, M = Li or Na) as a photocatalyst for the photoreduction of CO2 and degradation of toxic organic substances. The optimized NaCoO2 and LiCoO2 photocatalysts increased the photocatalytic CO2-CH4 conversion rate to 21.0 and 13.4 µmol g-1 h-1 under ultraviolet light irradiation and to 16.2 and 5.3 µmol g-1 h-1 under visible light irradiation, which is 17 times higher than that achieved by TiO2 P25. The rate constants of the optimized reactions of crystal violet (CV) with LiCoO2 and NaCoO2 were 2.29 × 10-2 and 4.35 × 10-2 h-1, respectively. The quenching effect of the scavengers and electron paramagnetic resonance in CV degradation indicated that active O2â¢-, 1O2, and h+ play the main role, whereas â¢OH plays a minor role for LiCoO2. The hyperfine splitting of the DMPO-â¢OH and DMPO-â¢CH3 adducts was aN = 1.508 mT, aHß = 1.478 mT and aN = 1.558 mT, aHß = 2.267 mT, respectively, whereas the hyperfine splitting of DMPO+⢠was aN = 1.475 mT. The quenching effect also indicated that active O2â¢- and h+ play the main role and that â¢OH and 1O2 play a minor role for NaCoO2. The hyperfine splitting of the DMPO-â¢OH and DMPO+⢠adducts was aN = 1.517 mT, aHß = 1.489 mT and aN = 1.496 mT, respectively. Discarded alkali metal battery electrode materials can be reused as photocatalysts to address environmental pollution.
Assuntos
Dióxido de Carbono , Poluentes Ambientais , Álcalis , Cobalto , Lítio , Óxidos/química , FotóliseRESUMO
Understanding the effects of temperature on Fusarium graminearum infection can provide theoretical guidance for chemical control of Fusarium head blight (FHB). Here, we evaluated the effects of various temperatures on biological fitness development of wild-type sensitive strain 2021 and carbendazim-resistance mutants conferring ß2-tubulin substitutions F167Y, E198K, and E198L. The results showed that mycelial growth and conidiation of four strains increased with the increase in temperature between 10 and 25°C. Conidia of F167Y displayed strong adaptability to low temperature. The virulence of the four strains was largely similar at the same temperature, showing an upward trend between 10 and 25°C. At 10°C, the hyphal growth of all strains was significantly inhibited, metabolism was slowed down, and the accumulation of secondary metabolites decreased. Subsequently, the production of deoxynivalenol (DON) and its intermediates pyruvate and aurofusarin decreased at low temperature, and the expression of DON biosynthesis-related genes Tri5, FgPK, and AUR decreased accordingly. At the same temperature, the aurofusarin production of the strains F167Y and E198K was higher than that of strains 2021 and E198L. The contents of DON and pyruvic acid in carbendazim-resistance mutants were higher than those in the wild-type strain 2021. The sensitivity of four strains to different fungicides changed at various temperatures. The sensitivity to most fungicides increased with decreasing temperature. The carbendazim-resistance mutants showed positive cross-resistance with other benzimidazoles. However, there was no cross-resistance to pyraclostrobin and azoles. These results would direct us to use fungicides preventing the infection of F. graminearum with changeable atmospheric temperature at the wheat flower stage.
Assuntos
Fusarium , Benzimidazóis/farmacologia , Carbamatos , Fusarium/genética , TemperaturaRESUMO
The first systematic synthesis of bismuth oxychloride/bismuth oxybromide/graphitic carbon nitride (BiOxCly/BiOmBrn/g-C3N4) nano-composites used a controlled hydrothermal method. The structure, morphology and characteristic of BiOxCly/BiOmBrn/g-C3N4 photocatalyst were measured by XRD, UV-vis-DRS, FT-IR, FE-TEM, FE-SEM-EDS, PL, BET, HR-XPS and EPR. Under visible light irradiation, the photodegradation activity was evaluated for the decolorization of crystal violet (CV) and 2-hydroxybenzoic acid (2-HBA) in aqueous solution. The catalytic performance showed that, when using sample BB2C1-4-250-30 wt% g-C3N4 composite as a photocatalyst, the best reaction-rate-constant (k) was 0.071 h-1. It was 1.5 times higher than the k value of BB2C1-4-250 as a photocatalyst. From the scavenging effect of various scavengers, the results of EPR showed that reactive OH was the main scavenger, while O2-, h+ and 1O2 were the second scavenger in CV degradation. In this study, a possible photodegradation mechanism was proposed and discussed. In this work, our method of BiOxCly/BiOmBrn/g-C3N4 preparation could be used for future mass production and the BiOxCly/BiOmBrn/g-C3N4 composite materials could be applied to the environmental pollution control in future.
Assuntos
Bismuto , Luz , Catálise , Fotólise , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Magnesium (Mg2+ ) has been shown to exert neuroprotective effects against hypoxia. However, it still remains elusive whether Mg2+ protected mouse hippocampal HT22 cells against hypoxia-evoked damages. Therefore, we aimed to investigate the function of Mg2+ and mechanisms associated with microRNA-221 (miR-221). HT22 cells were exposed to 3% O2 for 24 hours to induce hypoxic damages with 21% as a normoxic culture condition. The damages were monitored by viability, migration, and apoptosis of HT22 cells with or without Mg2+ pretreatment. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied to examine the alteration of miR-221, miR-210, and miR-17-5p. Transduction was carried out to artificially alter the expression of miR-221 and nerve growth factor (NGF), which was confirmed by qRT-PCR or Western blot assays. To blunt phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and nuclear factor κB (NF-κB), LY294002 (10 µM) and BAY 11-7082 (10 µM) were used. We observed Mg2+ protected HT22 cells against hypoxia-induced damages by upregulating miR-221. Further, miR-221 positively regulated NGF expression. Overexpression of NGF alleviated cell injury, while suppression of NGF aggravated cell injury. Moreover, miR-221 elevated NGF by inducing phosphorylation of regulators in PI3K/AKT and NF-κB transduction cascades and then alleviated cell injury. In conclusion, Mg2+ protected HT22 cells against hypoxia-induced damages by upregulation of miR-221 and NGF. These findings provided insights into the development of improved strategies for clinical application.
RESUMO
High altitude polycythemia (HAPC) is a serious public health problem among Han Chinese immigrants to the Qinghai-Tibetan Plateau. This study aims to explore the genetic basis of HAPC in the Han Chinese population. 484 male subjects (234 patients and 250 controls) were enrolled in this study. Genotyping was performed for polymorphisms of I/D in ACE, C1772T and G1790A in exon 12 of HIF-1α, rs2567206 in CYP1B1, rs726354 in SENP1, rs3025033 in VEGFA, rs7251432 in HAMP, rs2075800 in HSPA1L and rs8065364 in CARD14. Gene-gene interaction was assessed by multifactor dimensionality reduction. A significant association was seen between CARD14 polymorphism rs8065364 and risk of HAPC development in male Han Chinese, and the C allele of rs8065364 was a risk factor (odds ratio (OR)=1.59, 95% confidence interval (95% CI)=1.21-2.08). Gene-gene interaction analysis indicated that a synergistic relationship existed between rs3025033 and rs8065364 (1.00%), rs3025033 and rs726354 (0.18%), and rs726354 and rs8065364 (0.17%). The combination of rs8065364 in CARD14, rs3025033 in VEGFA and rs726354 in SENP1 was the best model to predict HAPC development in this study (testing accuracy=0.6183, p=0.0010, cross-validated consistency=10/10). Genetic interactions of SNPs in CARD14, SENP1 and VEGFA might represent a functional mechanism in the pathogenesis of HAPC.
Assuntos
Doença da Altitude/genética , Proteínas Adaptadoras de Sinalização CARD/genética , Endopeptidases/genética , Epistasia Genética , Guanilato Ciclase/genética , Proteínas de Membrana/genética , Policitemia/genética , Polimorfismo de Nucleotídeo Único , Fator A de Crescimento do Endotélio Vascular/genética , Adulto , Alelos , Altitude , Doença da Altitude/complicações , Doença da Altitude/diagnóstico , Doença da Altitude/etnologia , Povo Asiático , Estudos de Casos e Controles , Cisteína Endopeptidases , Expressão Gênica , Predisposição Genética para Doença , Proteínas de Choque Térmico HSP70/genética , Hepcidinas/genética , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Desequilíbrio de Ligação , Masculino , Razão de Chances , Peptidil Dipeptidase A/genética , Policitemia/complicações , Policitemia/diagnóstico , Policitemia/etnologia , TibetRESUMO
BACKGROUND: Chronic mountain sickness (CMS), originally characterized by excess hemoglobin (Hb), is currently diagnosed using score-based diagnostic criteria combined with excessive erythrocytosis and clinical symptoms. However, the current criteria have limited applicability. We applied these criteria to 1,029 Chinese Han males migrated to and have been stayed at the Qinghai-Tibet plateau (3,700-5,000 m) for 2-96 months to investigate the prevalence of CMS and its correlations with Hb concentration, altitude, and the length of residence. METHODS: Subjects were screened for CMS using the latest approved diagnostic criteria combined with excessive erythrocytosis and clinical symptoms. Hb concentrations were measured, and a cut-off point was determined with k-means clustering. Predisposing factors were evaluated with binary logistic analysis and curve fitting analysis. RESULTS: (1) The prevalence of CMS at the Qinghai-Tibetan plateau was 17.8% (183/1029 subjects, with CMS score ≥ 6, and Hb ≥ 210 g/L), which is higher than that previously reported. (2) While individuals were identified into two Hb clusters with a cut-off point of 200 g/L, in the low-Hb cluster (Hb < 200 g/L), the oxygen saturation remained stable as the Hb increased; in the high-Hb cluster (Hb ≥ 200 g/L), the oxygen saturation decreased as the Hb increased. (3) Two critical factors associated with CMS development were residence at an altitude of 4,500 m and a 60-month length of residence. CONCLUSIONS: Our presenting scoring system is more sensitive than previous diagnostic criteria and favors early screening and treatment of patients with CMS. Our finding suggests that an adjusted Hb threshold of 200 g/L (instead of 210 g/L) is more adaptable in Han individuals at all altitudes. The weight of Hb level should score ≥ 6 points using the CMS scoring system because of the pathophysiologic role of excessive erythrocytosis in patients with CMS. In addition, our data suggest the importance of early screening of CMS via regular medical examinations within the first 60 months of residence at high altitudes, especially >4500 m.
Assuntos
Adaptação Fisiológica , Doença da Altitude/diagnóstico , Altitude , Hemoglobinas/metabolismo , Oxigênio/sangue , Adulto , Doença da Altitude/sangue , Povo Asiático , China/epidemiologia , Doença Crônica , Etnicidade , Humanos , Hipóxia , Masculino , Programas de Rastreamento , Doenças Profissionais , Policitemia/diagnóstico , Policitemia/etiologia , Prevalência , Valores de Referência , Tibet/epidemiologia , Migrantes , Adulto JovemRESUMO
BACKGROUND: Hemoglobin concentration at high altitude is considered an important marker of high altitude adaptation, and native Tibetans in the Qinghai-Tibetan plateau show lower hemoglobin concentrations than Han people who have emigrated from plains areas. Genetic studies revealed that EPAS1 plays a key role in high altitude adaptation and is associated with the low hemoglobin concentration in Tibetans. Three single nucleotide polymorphisms (rs13419896, rs4953354, rs1868092) of noncoding regions in EPAS1 exhibited significantly different allele frequencies in the Tibetan and Han populations and were associated with low hemoglobin concentrations in Tibetans. METHODS: To explore the hereditary basis of high altitude polycythemia (HAPC) and investigate the association between EPAS1 and HAPC in the Han population, these 3 single nucleotide polymorphisms were assessed in 318 male Han Chinese HAPC patients and 316 control subjects. Genotyping was performed by high resolution melting curve analysis. RESULTS: The G-G-G haplotype of rs13419896, rs4953354, and rs1868092 was significantly more frequent in HAPC patients than in control subjects, whereas no differences in the allele or genotype frequencies of the 3 single nucleotide polymorphisms were found between HAPC patients and control subjects. Moreover, genotypes of rs1868092 (AA) and rs4953354 (GG) that were not observed in the Chinese Han in the Beijing population were found at frequencies of 1.6% and 0.9%, respectively, in our study population of HAPC patients and control subjects. CONCLUSIONS: Carriers of this EPAS1 haplotype (G-G-G, rs13419896, rs4953354, and rs1868092) may have a higher risk for HAPC. These results may contribute to a better understanding of the pathogenesis of HAPC in the Han population.
Assuntos
Povo Asiático/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Haplótipos , Montanhismo , Policitemia/etnologia , Policitemia/genética , Adaptação Fisiológica/genética , Altitude , Estudos de Casos e Controles , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Tibet/epidemiologiaRESUMO
BACKGROUND: Protein lysine lactylation (Kla) has been proved to be closely related to inflammatory diseases, but its role in periodontitis (PD) is unclear. Therefore, this study aimed to establish the global profiling of Kla in PD models in rats. METHODS: Clinical periodontal samples were collected, the inflammatory state of tissues was verified by H&E staining, and lactate content was detected by a lactic acid kit. Kla levels were detected by immunohistochemistry (IHC) and Western blot. Subsequently, the rat model of PD was developed and its reliability verified by micro-CT and H&E staining. Mass spectrometry analysis was conducted to explore the expression profile of proteins and Kla in periodontal tissues. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed, and a protein-protein interaction (PPI) network was constructed. The lactylation in RAW264.7 cells was confirmed by IHC, immunofluorescence and Western blot. The relative expression levels of inflammatory factors IL-1ß, IL-6, TNF-α, macrophage polarization-related factors CD86, iNOS, Arg1, and CD206 in RAW264.7 cells were detected by real time-quantitative polymerase chain reaction (RT-qPCR). RESULTS: We observed substantial inflammatory cell infiltration in the PD tissues, and the lactate content and lactylation levels were significantly increased. The expression profiles of protein and Kla were obtained by mass spectrometry based on the established rat model of PD. Kla was confirmed in vitro and in vivo. After inhibiting the "writer" of lactylation P300 in RAW264.7 cells, the lactylation levels decreased, and the expression of inflammatory factors IL-1ß, IL-6, and TNF-α increased. Meanwhile, the levels of CD86 and iNOS increased, and Arg1 and CD206 decreased. CONCLUSIONS: Kla may play an important role in PD, regulating the release of inflammatory factors and polarization of macrophages.
Assuntos
Lisina , Periodontite , Ratos , Animais , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Reprodutibilidade dos Testes , Macrófagos/metabolismo , Periodontite/metabolismo , Lactatos/metabolismo , Lactatos/farmacologiaRESUMO
BACKGROUND: Stromal interaction molecule 1 (STIM1) is a newly discovered Ca2+ sensor on the endoplasmic reticulum which is an indispensable part in the activation of store-operated Ca2+ channels (SOC). Recent studies demonstrate that SOC of pulmonary smooth muscle cells (PASMCs) were upregulated by chronic hypoxia which contribute to the enhanced pulmonary vasoconstriction and vascular remodeling. However, the exact role of STIM1 in the development of chronic hypoxic pulmonary hypertension(HPH) remains unclear. METHODS: In this study we investigated the cellular distribution and expression of STIM1 by immunofluorescence, qRTPCR and Western blotting methods in Wistar rat distal intrapulmonary arteries under normal and chronic hypobaric hypoxic conditions. In vitro, Wistar rat PASMCs were isolated and cultured. PASMCs were transfected with siRNA targeting STIM1 gene by liposome. The expression of STIM1 protein was detected by Western blotting. [3H]-thymidine ([3H]-TdR) incorporation were performed to detect PASMCs proliferation. The cell cycle was analyzed by flow cytometry. The SOC-mediated Ca2+ influx was calculated by Ca2+ fluorescence imaging and the nuclear translocation of NFATc3 was determined by immunofluorescence and Western blot analysis of nuclear extracts. RESULTS: We found that during the development of HPH and the initiation of vascular remodeling, the mRNA and protein expression levels of STIM1 significantly increased in the distal intrapulmonary arteries. Moderate hypoxia significantly promotes PASMCs proliferation and cell cycle progression. Silencing of STIM1 significantly decreased cellular proliferation and delayed the cell cycle progression induced by hypoxia. Silencing of STIM1 also significantly decreased SOC-mediated Ca2+ influx and inhibited the nuclear translocation of NFATc3 in hypoxic PASMCs. CONCLUSION: Our findings suggest that chronic hypobaric hypoxia upregulates the expression of STIM1 in the distal intrapulmonary arteries which plays an important role in the hypoxia-induced PASMCs proliferation via SOC/Ca2+/NFAT pathway and may represent a novel therapeutic target for the prevention of hypoxia pulmonary hypertension.
Assuntos
Canais de Cálcio/biossíntese , Sinalização do Cálcio/fisiologia , Hipóxia/metabolismo , Glicoproteínas de Membrana/biossíntese , Miócitos de Músculo Liso/metabolismo , Fatores de Transcrição NFATC/biossíntese , Animais , Canais de Cálcio/genética , Proliferação de Células , Células Cultivadas , Inativação Gênica/fisiologia , Hipóxia/genética , Hipóxia/patologia , Masculino , Glicoproteínas de Membrana/genética , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Fatores de Transcrição NFATC/antagonistas & inibidores , Fatores de Transcrição NFATC/genética , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Ratos , Ratos Wistar , Molécula 1 de Interação EstromalRESUMO
The mitochondrion is an important cellular component responsible for regulating energy, oxidative metabolism, and acclimatization to high altitude. This study is aimed at investigating the impact of long-term exposure to hypoxia on the amount of mitochondrial DNA (mtDNA) in rat livers. Male Sprague-Dawley rats were randomized and exposed to normoxia (group I), or 5,000 m (barometric pressure about 405.35 mmHg) above the sea level (a hypoxic condition) for 23 and 1 h normoxia daily for five consecutive days (group II), 15 days (group III), and 30 days (group IV), respectively. The levels of plasma malondialdehyde (MDA), homocysteine (Hcy), superoxide dismutase (SOD), and alanine aminotransferase (ALT), the contents of liver mtDNA, mitochondrial transcription factor A (mtTFA), cytochrome oxidase 1 (COX1), COX2, and COX3 mRNA transcripts, and mitochondrial respiratory activity were examined immediately after the last cycle. In comparison with that in control rats, 5-15 cycles of hypoxia/normoxia significantly increased the levels of plasma MDA and ALT, but reduced the levels of Hcy and SOD, accompanied by impairing liver respiratory function in rats. Long-term (30) cycles of hypoxia/normoxia reduced the levels of plasma MDA and ALT, but increased the levels of SOD and Hcy, accompanied by decreased mtTFA expression and mtDNA amount, improved mitochondrial respiratory function in rat liver, when compared that of 5-15 cycles of hypoxia/normoxia. Our data indicate that long-term cycles of hypoxia/normoxia increases the amount of mtDNA and up-regulates COX expression, contributing to acclimatization to very high altitude in rats.
Assuntos
Aclimatação/genética , Doença da Altitude/fisiopatologia , DNA Mitocondrial/biossíntese , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias Hepáticas/metabolismo , Animais , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To evaluate the effects of hypobaric hypoxia on the expressions of death receptor 5 (DR5) and cellular FLICE-like inhibitory protein (c-FLIP) and the distribution of c-FLIP in the rat testis. METHODS: Forty adult male SD rats were randomly divided into four groups of equal number: normoxia control, 3 d hypoxia, 15 d hypoxia and 30 d hypoxia. The control rats were raised at 300 m above the sea level, while the latter three groups of rats in a hypobaric chamber at a simulated altitude of 4000 m for 5, 15 and 30 days, respectively. Then the expressions of DR5 and c-FLIP were detected by immunoblotting and the distribution of c-FLIP in the testis observed by immunofluorescence. RESULTS: The expressions of DR5 were 2.04 +/- 0.11, 1.97 +/- 0.12 and 2.34 +/- 0.11 in the 3 d, 15 d and 30 d hypoxia groups, respectively, significantly higher than 1.78 +/- 0.09 in the normoxia group (P < 0.05). The expressions of c-FLIP were 0.87 +/- 0.03 and 0.74 +/- 0.07 in the 15 d and 30 d hypoxia groups, respectively, significantly lower than 1.03 +/- 0.02 in the normoxia group (P < 0.05). CONCLUSION: Simulated hypobaric hypoxia at 4000 m above the sea level increased the expression of DR5 and inhibited that of c-FLIP in the rat testis.
Assuntos
Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD/metabolismo , Hipóxia/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Testículo/metabolismo , Animais , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
The uplift of the Qinghai Tibet Plateau has led to a drastic change in the climate in Central Asia, from warm and rainy, to dry and less rainfall. Ammopiptanthus nanus, a rare evergreen broad-leaved shrub distributed in the temperate desert region of Central Asia, has survived the drastic climate change in Central Asia caused by the uplift of the Qinghai-Tibet Plateau. Ascorbate oxidase (AO) regulates the redox status of the apoplast by catalyzing the oxidation of ascorbate acid to dehydroascorbic acid, and plays a key role in the adaptation of plants to environmental changes. Analyzing the evolution, environmental response, and biological functions of the AO family of A. nanus is helpful for understanding how plant genome evolution responds to climate change in Central Asia. A total of 16 AOs were identified in A. nanus, all of which contained the ascorbate oxidase domain, most of which contained transmembrane domain, and many were predicted to be localized in the apoplast. Segmental duplication and tandem duplication are the main factors driving the gene amplification of the AO gene family in A. nanus. Gene expression analysis based on transcriptome data and fluorescence quantitative PCR, as well as enzyme activity measurements, showed that the expression levels of AO genes and total enzyme activity decreased under short-term osmotic stress and low-temperature stress, but the expression of some AO genes (AnAO5, AnAO13, and AnAO16) and total enzyme activity increased under 7 days of cold stress. AnAO5 and AnAO11 are targeted by miR4415. Further functional studies on AnAO5 showed that AnAO5 protein was localized in the apoplast. The expression of AnAO5 in yeast cells and the transient expression in tobacco enhanced the tolerance of yeast and tobacco to low-temperature stress, and the overexpression of AnAO5 enhanced the tolerance of Arabidopsis seedlings to cold stress. Our research provides important data for understanding the role of AOs in plant adaptation to environmental change.
RESUMO
The extensive consumption of fossil fuels increases CO2 concentration in the atmosphere, resulting in serious global warming problems. Meanwhile, the problem of water contamination by organic substances is another significant global challenge. We have successfully synthesized ZnGa1.01Te2.13/g-C3N4 (ZGT/GCN) composites for the first time as effective photocatalysts for both pollutant degradation and CO2 reduction. ZGT/GCN composites were synthesized by a simple hydrothermal method. The prepared photocatalysts were characterized by XRD, SEM, TEM-EDS, DRS, BET, PL, and XPS. The ZGT/GCN heterojunction exhibited considerably enhanced photocatalytic activity in the degradation of crystal violet (CV) as well as in the photoreduction of CO2 when compared to pure ZGT and GCN semiconductors. The optimal rate constant for CV degradation was obtained with the ZGT-80%GCN composite (0.0442 h-1), which is higher than the constants obtained with individual ZGT and GCN by 7.75 and 1.63 times, respectively. Moreover, the CO2 reduction yields into CH4 by ZGT-80%GCN was 1.013 µmol/g in 72 h, which is 1.21 and 1.08 times larger than the yields obtained with ZGT and GCN. Scavenger and ESR tests were used to propose the photocatalytic mechanism of the ZGT/GCN composite as well as the active species in the CV degradation.
RESUMO
BACKGROUND: The role of genetics in determining an individual's susceptibility to high altitude pulmonary edema (HAPE) is unclear. However a number of genetic polymorphisms have recently been found to be overrepresented in patients with HAPE. Changes at the mitochondrial level may play an important role in the human body's adaptation to hypoxia. Polymorphisms of mitochondrial DNA (mtDNA) have been shown to be responsible for differences in organelle function. Therefore, the frequency of mtDNA 3397A/G and 3552T/A polymorphisms were studied to determine their potential role in HAPE. OBJECTIVES: To further study the role of mtDNA 3397A/G and 3552T/A variations of reduced nicotinamide adenosine dinucleotide dehydrogenase 1 in HAPE susceptibility. METHODS: The single-nucleotide polymorphisms of mtDNA 3397 and 3552 in patients with HAPE (n = 132) and their matched control subjects (n = 233) were studied using polymerase chain reaction sequencing. RESULTS: The frequency of mtDNA 3397G in the HAPE group (2.3%) was significantly higher than that of the control group (0%; P = .021; odds ratio, 2.806; 95% confidence interval, 2.443 to 3.223). The frequency of mtDNA 3552A in the HAPE group (6.8%) also was significantly higher than in the control group (1.7%; P = .012; odds ratio, 4.198; 95% confidence interval, 1.264 to 13.880). CONCLUSIONS: In this study, we present the first evidence of differences in mtDNA polymorphism frequencies between HAPE victims and healthy Han Chinese. Genotypes of mtDNA 3397G and 3552A were correlated with HAPE susceptibility. This result could contribute to defining the role of the mitochondrial genome in the pathogenesis of HAPE.
Assuntos
Doença da Altitude/genética , Povo Asiático/genética , DNA Mitocondrial/genética , Hipertensão Pulmonar/genética , Polimorfismo de Nucleotídeo Único , Adulto , Doença da Altitude/etnologia , Estudos de Casos e Controles , China , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Hipertensão Pulmonar/etnologia , Masculino , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVE: The purpose of this study was to examine the relationship between acute mountain sickness (AMS) and the fraction of exhaled nitric oxide (Fe(NO)) and carbon monoxide (Fe(CO)) before ascent to high altitude and to evaluate their predictive value for AMS. METHODS: A total of 314 healthy young male recruits were voluntarily enrolled. Before ascent to an elevation of 4300 m, their Fe(NO) and Fe(CO) values, demographic factors, drinking and smoking history, vital capacity, and forced vital capacity were obtained. The investigators followed the subjects in the first exposure week to obtain their Lake Louise Score (LLS) each day. Subjects with LLS > 4, headache, and at least 1 other symptom were diagnosed with AMS, and the highest LLS of each individual during 7 days was considered the final LLS score. RESULTS: The AMS group had lower Fe(NO) (P = .003) and Fe(CO) (P < .001) values, and a lower smoking rate (P < .001) than the non-AMS group. Mean Fe(NO) and Fe(CO) values were 11.03 ppb (95% CI, 9.07 to 12.98) and 4.39 ppm (95% CI, 3.76 to 5.02), respectively, in the AMS group, and 14.74 ppb (95% CI, 13.25 to 16.23) and 6.10 ppm (95% CI, 5.49 to 6.72), respectively, in the non-AMS group (P < .0001). Using linear regression, both Fe(NO) and Fe(CO) were found to be significantly associated with the group's maximal LLS. Using logistic regression, Fe(NO) and Fe(CO) were also found to be significantly associated with AMS. CONCLUSIONS: Basal Fe(NO) and Fe(CO) are significantly negatively correlated with AMS development. However, the gases have only modest predictive value for the development of AMS.