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1.
Proc Biol Sci ; 291(2031): 20240642, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39288804

RESUMO

Nutrient addition, particularly nitrogen, often increases plant aboveground biomass but causes species loss. Asymmetric competition for light is frequently assumed to explain the biomass-driven species loss. However, it remains unclear whether other factors such as water can also play a role. Increased aboveground leaf area following nitrogen addition and warming may increase transpiration and cause water limitation, leading to a decline in diversity. To test this, we conducted field measurements in a grassland community exposed to nitrogen and water addition, and warming. We found that warming and/or nitrogen addition significantly increased aboveground biomass but reduced species richness. Water addition prevented species loss in either nitrogen-enriched or warmed treatments, while it partially mitigated species loss in the treatment exposed to increases in both temperature and nitrogen. These findings thus strongly suggest that water limitation can be an important driver of species loss as biomass increases after nitrogen addition and warming when soil moisture is limiting. This result is further supported by a meta-analysis of published studies across grasslands worldwide. Our study indicates that loss of grassland species richness in the future may be greatest under a scenario of increasing temperature and nitrogen deposition, but decreasing precipitation.


Assuntos
Biodiversidade , Biomassa , Pradaria , Nitrogênio , Água , Nitrogênio/metabolismo , Temperatura , Aquecimento Global , Poaceae/fisiologia
2.
Glob Chang Biol ; 30(7): e17430, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39031432

RESUMO

The relationship between plant aboveground biomass and diversity typically follows a unimodal pattern, showing a positive correlation in resource-poor habitats and a negative correlation in resource-rich environments. Precipitation is a crucial resource for both plant biomass and diversity in terrestrial ecosystems. However, the impact of precipitation changes on the relationship between plant biomass and diversity remains unclear. We conduct a water addition field experiment in a semiarid grassland and identify a unimodal relationship between plant biomass and species richness under ambient conditions. Water addition delays the declining phase of this unimodal curve and shift it upward compared to ambient conditions. Our meta-analysis of water addition experiments conducted across major biomes worldwide (grassland, shrubland, desert, and forest) supports this finding, while water reduction does not alter the biomass-diversity relationship. Water addition increases biomass in all climate but only increases species richness in arid and semiarid climate. Similarly, water reduction decreases biomass in all climate but only reduces species richness in arid and semiarid climate. Species richness in dry subhumid and humid climate does not change significantly. Furthermore, our field experiment shows that water addition increases plant diversity while decreasing soil inorganic nitrogen levels. The increase in one resource, such as water, leads to the scarcity of another, such as nutrient, thus postponing the declining phase of the plant biomass-diversity relationship typically observed in resource-rich habitats. Our research contributes to predicting the plant biomass-diversity relationship under changing precipitation conditions and highlights the complex interplay between water availability, nutrient level, and plant diversity.


Assuntos
Biodiversidade , Biomassa , Água , Ecossistema , Pradaria , Nitrogênio/análise , Nitrogênio/metabolismo , Plantas , Chuva , Solo/química
3.
Neurochem Res ; 49(10): 2682-2698, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39002091

RESUMO

Alzheimer's disease (AD) represents the most widespread neurodegenerative disorder, distinguished by a gradual onset and slow progression, presenting a substantial challenge to global public health. The mitochondrial-associated membrane (MAMs) functions as a crucial center for signal transduction and material transport between mitochondria and the endoplasmic reticulum, playing a pivotal role in various pathological mechanisms of AD. The dysregulation of mitochondrial quality control systems is considered a fundamental factor in the development of AD, leading to mitochondrial dysfunction and subsequent neurodegenerative events. Recent studies have emphasized the role of MAMs in regulating mitochondrial quality control. This review will delve into the molecular mechanisms underlying the imbalance in mitochondrial quality control in AD and provide a comprehensive overview of the role of MAMs in regulating mitochondrial quality control.


Assuntos
Doença de Alzheimer , Mitocôndrias , Membranas Mitocondriais , Doença de Alzheimer/metabolismo , Humanos , Mitocôndrias/metabolismo , Animais , Membranas Mitocondriais/metabolismo , Retículo Endoplasmático/metabolismo
4.
J Org Chem ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39294860

RESUMO

A novel reaction of cyclic and acyclic secondary amines with in situ-generated allene intermediate species from nitro-substituted donor-acceptor cyclopropanes is reported. In the presence of a simple inorganic base, NaOH, tetrasubstituted enamine derivatives can be obtained in moderate to excellent yields. The reaction is operationally easy, features mild reaction conditions and simple inorganic bases, and is free of transition metals.

5.
J Craniofac Surg ; 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39325131

RESUMO

OBJECTIVE: The objective of this study was to investigate and assess the clinical data of 123 patients diagnosed with congenital branchial cleft anomalies (CBCAs), to summarize pivotal aspects concerning their clinical diagnosis and treatment process. MATERIALS AND METHODS: The authors conducted a retrospective analysis of 123 patients who underwent surgical intervention for CBCAs at our institution between August 2005 and September 2021. The clinical demographic characteristics of the patients, primary symptoms, treatment chronology, preoperative diagnostic assessments, surgical strategies, occurrences of postoperative complications, and rates of recurrence were subjected to statistical analysis. RESULTS: Among the enrolled patients, there were 43 cases (34.9%) of congenital first branchial cleft anomalies (CFBCA), 76 cases (61.8%) of congenital second branchial cleft anomalies (CSBCA), and 4 cases (3.3%) of congenital third branchial cleft anomalies (CTBCA), with no cases of congenital fourth branchial anomalies (CFBA). Notably, among all cases, 43 anomalies were situated in the upper one-third of the sternocleidomastoid muscle, while 80 anomalies were located in the lower one-third. Different surgical approaches were selected for patients based on the specific type of anomaly presented. Following surgery, there was recurrence in 14 cases, with factors such as patient age, clinical categorization, lesion type, and history of preoperative infection and surgical intervention identified as primary risk factors for it. CONCLUSION: CBCAs represent comparatively uncommon disorders affecting the head and cervical regions in clinical practice. Diagnostic modes such as ultrasonography and lipiodol contrast radiography can be used for accurate diagnosis, with surgical intervention serving as the primary therapeutic method.

6.
Zhongguo Zhong Yao Za Zhi ; 49(5): 1388-1396, 2024 Mar.
Artigo em Zh | MEDLINE | ID: mdl-38621987

RESUMO

This study aims to systematically review the clinical features and outcome indicators in randomized controlled trial(RCT) of traditional Chinese medicine(TCM) intervention in septic kidney injury and provide a reference for optimizing clinical study design and building the core outcome set(COS) of TCM treatment of septic kidney injury. Computer searches were conducted on PubMed, Cochrane Library, EMbase, Web of Science, CNKI, Wanfang, VIP, and SinoMed to find published RCT of TCM intervention in septic kidney injury in the past five years, extract the basic characteristics, intervention measures, outcome indicators, and other data of included studies, and conduct descriptive analysis. 53 RCTs were included, and the sample size was mostly concentrated in 60-80 cases, with abdominal infection being the most common(15 articles, 83.3%) and the TCM syndrome of blood stasis being the most frequent(9 articles, 50.0%). The frequency of intervention methods from high to low were TCM decoction(28 articles, 52.8%), Chinese patent medicine(22 articles, 41.5%), and combined TCM therapy(3 articles, 7.5%); the intervention time of the trial was more than 7 d(34 articles, 69.4%). The risk of bias in included studies was unclear. A total of 84 outcome indicators were involved, which were divided into 9 fields, including 63 physical and chemical tests(305 times, 72.2%), 4 kinds of disease degree(48 times, 11.6%), 4 kinds of clinical effective rate(15 times, 3.6%), 1 kind of quality of life(1 time, 0.2%), 2 kinds of economic evaluation(14 times, 3.3%), 1 kind of TCM disease(9 times, 2.1%), 2 kinds of long-term prognosis(16 times, 3.8%), 2 kinds of safety events(6 times, 1.4%), and 5 other indicators(8 times, 0.7%). The cumulative frequency was 422 times, among which the outcome indicators with higher frequency were inflammatory factors(42 articles, 79.2%) and markers of renal function and kidney injury(40 articles, 75.5%). Only 1(1.9%) of the included articles mentioned primary and secondary outcome indicators, and 6 articles(11.3%) mentioned safety events, 13 articles(24.5%) mentioned economic assessment. The RCT quality of TCM intervention in septic renal injury was generally low, and the reference standards for sepsis, kidney injury, and TCM syndrome diagnosis were not uniform. There are some problems in outcome indicators, such as unclear distinction between primary and secondary indicators, neglect of endpoint indicators, lack of application of TCM characteristic indicators, and insufficient attention to safety events and economic assessment. It is suggested that the quality of clinical research methodology should be improved in the future, and the COS should be constructed to provide high-level evidence-based evidence for TCM intervention in septic kidney injury.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , Ensaios Clínicos Controlados Aleatórios como Assunto , Sepse , Humanos , Medicamentos de Ervas Chinesas/uso terapêutico , Sepse/tratamento farmacológico , Masculino , Resultado do Tratamento , Feminino , Idoso , Adulto , Pessoa de Meia-Idade , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/terapia
7.
Hum Mol Genet ; 30(3-4): 172-181, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33480989

RESUMO

Telomere fusions lead to a state of genomic instability, and are thought to drive clonal evolution and tumorigenesis. Telomere fusions occur via both Classical and Alternative Non-Homologous End Joining repair pathways. AsiDNA is a DNA repair inhibitor that acts by mimicking a DNA double strand break (DSB) and hijacking the recruitment of proteins involved in various DNA repair pathways. In this study, we investigated whether the inhibition of DSB-repair pathways by AsiDNA could prevent telomere fusions during crisis. The present study showed that AsiDNA decreased the frequency of telomere fusions without affecting the rate of telomere erosion. Further, it indicated that AsiDNA does not impact the choice of the repair pathway used for the fusion of short dysfunctional telomeres. AsiDNA is thought to prevent short telomeres from fusing by inhibiting DNA repair. An alternative, non-mutually exclusive possibility is that cells harbouring fusions preferentially die in the presence of AsiDNA, thus resulting in a reduction in fusion frequency. This important work could open the way for investigating the use of AsiDNA in the treatment of tumours that have short dysfunctional telomeres and/or are experiencing genomic instability.


Assuntos
Reparo do DNA/efeitos dos fármacos , Encurtamento do Telômero , Telômero/metabolismo , Células HCT116 , Humanos
8.
BMC Microbiol ; 23(1): 275, 2023 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-37773099

RESUMO

BACKGROUND: Gut microbiota play a key role in the nutrition of many marine herbivorous fishes through hindgut fermentation of seaweed. Gut microbiota composition in the herbivorous fish Kyphosus sydneyanus (family Kyphosidae) varies between individuals and gut sections, raising two questions: (i) is community composition stable over time, especially given seasonal shifts in storage metabolites of dietary brown algae, and (ii) what processes influence community assembly in the hindgut? RESULTS: We examined variation in community composition in gut lumen and mucosa samples from three hindgut sections of K. sydneyanus collected at various time points in 2020 and 2021 from reefs near Great Barrier Island, New Zealand. 16S rRNA gene analysis was used to characterize microbial community composition, diversity and estimated density. Differences in community composition between gut sections remained relatively stable over time, with little evidence of temporal variation. Clostridia dominated the proximal hindgut sections and Bacteroidia the most distal section. Differences were detected in microbial composition between lumen and mucosa, especially at genus level. CONCLUSIONS: High variation in community composition and estimated bacterial density among individual fish combined with low variation in community composition temporally suggests that initial community assembly involved environmental selection and random sampling/neutral effects. Community stability following colonisation could also be influenced by historical contingency, where early colonizing members of the community may have a selective advantage. The impact of temporal changes in the algae may be limited by the dynamics of substrate depletion along the gut following feeding, i.e. the depletion of storage metabolites in the proximal hindgut. Estimated bacterial density, showed that Bacteroidota has the highest density (copies/mL) in distal-most lumen section V, where SCFA concentrations are highest. Bacteroidota genera Alistipes and Rikenella may play important roles in the breakdown of seaweed into useful compounds for the fish host.


Assuntos
Microbioma Gastrointestinal , Perciformes , Animais , RNA Ribossômico 16S/genética , Peixes/microbiologia , Sistema Digestório , Bactérias/genética , Bacteroidetes/genética
9.
Anticancer Drugs ; 34(5): 669-679, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36730426

RESUMO

It was recently found that lncRNA PROX1 antisense RNA 1 (PROX1-AS1) manifested oncogenicity in a variety of malignancies. This work intended to investigate the molecular mechanisms of PROX1-AS1 in colorectal cancer (CRC) development and immune evasion. In this study, both PROX1-AS1 and PD-L1 expressions were lifted in CRC tissues and cells. PROX1-AS1 interference restrained CRC cell proliferation, migration, invasion, as well as CD8 + T-lymphocyte apoptosis, but increased the cytotoxicity and percentage of CD8 + T lymphocytes. The inhibitory effects of PROX1-AS1 inhibition on CRC progression and immune escape were positively related to PD-L1 suppression. PROX1-AS1 absorbed miR-520d to upregulate PD-L1 expression. PROX1-AS1 facilitated CRC progression and immune escape by targeting miR-520d. Furthermore, PROX1-AS1 deletion impaired CRC tumor growth in vivo . To sum up, this study affirmed that PROX1-AS1 could absorb miR-520d to upregulate PD-L1 in CRC, thereby promoting tumor progression and immune escape.


Assuntos
Neoplasias Colorretais , MicroRNAs , RNA Longo não Codificante , Humanos , MicroRNAs/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Antígeno B7-H1/metabolismo , Neoplasias Colorretais/patologia , Proliferação de Células/genética , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica
10.
Phys Chem Chem Phys ; 25(47): 32452-32459, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37991918

RESUMO

A15-type compound Nb3Sn has attracted much attention due to its relatively high critical temperature and critical field of superconductivity, making it a leading material for superconducting applications. In this study, we investigate the structural instability and superconductivity of Nb3Sn under hydrostatic pressure using first-principles calculations. We determine the electronic properties, phonon dispersion, electron-phonon coupling and the superconducting gap for Nb3Sn at pressures ranging from ambient to 9 GPa. Our results show that a significant electron density is present near the Fermi level due to the van Hove singularity, indicating the strong electron-phonon coupling. The phonon dispersion of Nb3Sn exhibits Kohn anomalies at three different wave vectors at a lower temperature. Moreover, above a pressure of 6 GPa, the charge density wave (CDW) instability disappeared, suggesting that pressure inhibits the CDW phase. The superconducting temperature is predicted to be TC = 18.62 K under ambient conditions, which is well consistent with the experimental results. We find that both the CDW and superconducting orders respond to pressure, with their transition temperatures decreasing as the pressure increases below 6 GPa. Above 6 GPa, the superconducting transition temperature increases slowly with pressure. Our results suggest that the instability in Nb3Sn is driven by the softening of the phonon modes due to the CDW caused by strong electron-phonon coupling. Therefore, the CDW phase and superconducting phase of Nb3Sn coexist at low pressure.

11.
Appl Microbiol Biotechnol ; 107(10): 3205-3216, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37058230

RESUMO

Botulinum neurotoxin (BoNTs; serotypes A, B, E, and F) cause botulism disease in humans, which could be effectively treated using antitoxins. Herein, we established a novel receptor-binding domain (RBD)-based antitoxin using recombinant C terminal heavy chain (Hc) domains of BoNTs as immunogens. Immunization of horses with these recombinant Hc domains allowed the purification and digestion of IgGs from hyper-immune sera to produce high-quality and high-efficiency monovalent botulism antitoxin F(ab')2 against each BoNT (M-BATs). However, these M-BATs could not bind or neutralize other serotypes of BoNTs, and that there were no cross-protective effects among these M-BATs. This suggested the need to prepare tetravalent antitoxins to neutralize the four BoNTs simultaneously. Thus, these M-BATs were formulated into a novel tetravalent botulism antitoxin (T-BAT), in which a 10-ml volume contained 10000 IU of BoNT/A and 5000 IU of BoNT/B, BoNT/E, and BoNT/F antitoxins. The novel antitoxin preparation could prevent and treat the four mixed botulinum neurotoxins simultaneously in vivo, representing strong efficacy in an animal poisoning model. Moreover, these antibodies in T-BAT could bind the RBD, whereas conventional antitoxins based on inactivated toxins mainly bind the light chain or heavy chain translocation domain (HN) and weakly bind the important RBD in current experimental conditions. The high levels of RBD-specific novel antitoxins can efficiently bind the RBD and neutralize natural or recombinant toxins containing this RBD. The findings of the present study experimentally support the use of RBD-specific antitoxins to treat BoNT serotype A, B, E, and F-mediated botulism. This study demonstrated the concept of developing potent novel multivalent antitoxins against all BoNTs or other toxins, using the RBD of these toxins as an alternative antigen to inactivated toxins. KEY POINTS: • Antitoxins based on the receptor-binding domains of botulinum neurotoxins were made. • Novel antitoxin binds RBD; traditional antitoxin mainly binds light chain or HN domain. • A tetravalent antitoxin could prevent and treat the four mixed neurotoxins in vivo.


Assuntos
Antitoxinas , Toxinas Botulínicas Tipo A , Botulismo , Humanos , Animais , Cavalos , Antitoxina Botulínica , Botulismo/prevenção & controle , Neurotoxinas , Imunização
12.
Appl Microbiol Biotechnol ; 107(23): 7197-7211, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37741939

RESUMO

Tetanus toxin (TeNT) and botulinum neurotoxins (BoNTs) are neuroprotein toxins, with the latter being the most toxic known protein. They are structurally similar and contain three functional domains: an N-terminal catalytic domain (light chain), an internal heavy-chain translocation domain (HN domain), and a C-terminal heavy chain receptor binding domain (Hc domain or RBD). In this study, fusion functional domain molecules consisting of the TeNT RBD (THc) and the BoNT/A RBD (AHc) (i.e., THc-Linker-AHc and AHc-Linker-THc) were designed, prepared, and identified. The interaction of each Hc domain and the ganglioside receptor (GT1b) or the receptor synaptic vesicle glycoprotein 2 (SV2) was explored in vitro. Their immune response characteristics and protective efficacy were investigated in animal models. The recombinant THc-linker-AHc and AHc-linker-THc proteins with the binding activity had the correct size and structure, thus representing novel subunit vaccines. THc-linker-AHc and AHc-linker-THc induced high levels of specific neutralizing antibodies, and showed strong immune protective efficacy against both toxins. The high antibody titers against the two novel fusion domain molecules and against individual THc and AHc suggested that the THc and AHc domains, as antigens in the fusion functional domain molecules, do not interact with each other and retain their full key epitopes responsible for inducing neutralizing antibodies. Thus, the recombinant THc-linker-AHc and AHc-linker-THc molecules are strong and effective bivalent biotoxin vaccines, protecting against two biotoxins simultaneously. Our experimental design will be valuable to develop recombinant double-RBD fusion molecules as potent bivalent subunit vaccines against bio-toxins. KEY POINTS: • Double-RBD fusion molecules from two toxins had the correct structure and activity. • THc-linker-AHc and AHc-linker-THc efficiently protected against both biotoxins. • Such bivalent biotoxin vaccines based on the RBD are a valuable experimental design.


Assuntos
Toxinas Botulínicas Tipo A , Toxina Tetânica , Animais , Toxina Tetânica/genética , Toxina Tetânica/metabolismo , Toxinas Botulínicas Tipo A/genética , Toxinas Botulínicas Tipo A/metabolismo , Ligação Proteica , Anticorpos Neutralizantes , Vacinas de Subunidades Antigênicas/genética
13.
BMC Public Health ; 23(1): 571, 2023 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973714

RESUMO

BACKGROUND: Since July 2021, some countries and regions have initiated the vaccination of minors against coronavirus disease (COVID-19), and parental COVID-19 vaccine hesitancy will affect the vaccination of minors. We aimed to identify the level of parental hesitancy to vaccinate their children against COVID-19 in Taiwan and the factors associated with vaccine hesitancy. METHODS: We conducted a population-based, self-administered online questionnaire in Taiwan to assess parental hesitancy and the factors influencing their children's vaccination against COVID-19. RESULTS: Among 384 respondents, 64.1% were hesitant to have their children vaccinated against COVID-19. Mothers were more likely to hesitate to vaccinate their teens than their fathers (67.5% vs. 50%, P < 0.005). Multiple regression results showed that parents who were hesitant to vaccinate themselves (OR = 3.81, 95% CI:2.07-7.02) and those who scored lower on their perception of their children's vaccination (OR = 9.73, 95% CI:5.62-16.84) were more hesitant to vaccinate their children with COVID-19 vaccine. CONCLUSIONS: According to the study findings, 64.1% of Taiwanese parents were hesitant to vaccinate their children against COVID-19. Parents who were hesitant to receive the COVID-19 vaccine for themselves and had negative views of the vaccine for their children were more likely to be hesitant to vaccinate their children. An in-depth discussion of the factors affecting vaccine hesitancy and targeted health education is conducive to promoting vaccination in children with COVID-19.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Adolescente , Criança , Humanos , Vacinas contra COVID-19/uso terapêutico , Taiwan/epidemiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pais , Vacinação
14.
Zygote ; 31(2): 163-172, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36617979

RESUMO

Aberrant DNA methylation patterns in sperm are a cause of embryonic failure and infertility, and could be a critical factor contributing to male recurrent spontaneous abortion (RSA). The purpose of this study was to reveal the potential effects of sperm DNA methylation levels in patients with male RSA. We compared sperm samples collected from fertile men and oligoasthenospermia patients. Differentially methylated sequences were identified by reduced representation bisulfite sequencing (RRBS) methods. The DNA methylation levels of the two groups were compared and qRT-PCR was used to validate the expression of genes showing differential methylation. The results indicated that no difference in base distribution was observed between the normal group and the patient group. However, the chromosome methylation in these two groups was markedly different. One site was located on chromosome 8 and measured 150 bp, while the other sites were on chromosomes 9, 10, and X and measured 135 bp, 68 bp, and 136 bp, respectively. In particular, two genes were found to be hypermethylated in these patients, one gene was DYDC2 (placed in the differential methylation region of chromosome 10), and the other gene was NXF3 (located on chromosome X). Expression levels of DYDC2 and NXF3 in the RSA group were significantly lower than those in the normal group (P < 0.05). Collectively, these results demonstrated that changes in DNA methylation might be related to male RSA. Our findings provide important information regarding the potential role of sperm DNA methylation in human development.


Assuntos
Aborto Habitual , Metilação de DNA , Feminino , Gravidez , Humanos , Masculino , Sêmen , Espermatozoides/metabolismo , Aborto Habitual/genética , Aborto Habitual/metabolismo , Análise do Sêmen
15.
Anaerobe ; 82: 102764, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37479022

RESUMO

OBJECTIVES: The mature botulinum neurotoxin (BoNT) is a long peptide chain consisting of a light chain (L) and a heavy chain (H) linked by a disulfide bond, where the heavy chain is divided into a translocation domain and an acceptor binding domain (Hc). In this study, we further explored the biology activity and characteristics of recombinant L-HN fragment (EL-HN) composed of the L and HN domains of BoNT/E in vivo and in vitro. METHODS: Neurotoxicity of L-HN fragments from botulinum neurotoxins was assessed in mice. Cleavage of dichain EL-HN in vitro and in neuro-2a cells was assessed and compared with that of single chain EL-HN. Interaction of HN domain and the receptor synaptic vesicle glycoprotein 2C (SV2C) was explored in vitro and in neuro-2a cells only expressing SV2C. RESULTS: We found that the 50% mouse lethal dose of the nicked dichain EL-HN fragment (EL-HN-DC) was 0.5 µg and its neurotoxicity was the highest among the L-HN's of the four serotypes of BoNT (A/B/E/F). The cleavage efficiency of EL-HN-DC toward synaptosome associated protein 25 (SNAP25) in vitro was 3-fold higher than that of the single chain at the cellular level, and showed 200-fold higher animal toxicity. The EL-HN-DC fragment might enter neuro-2a cells via binding to SV2C to efficiently cleave SNAP25. CONCLUSIONS: The EL-HN fragment showed good biological activities in vivo and in vitro, and could be used as a drug screening model and to further explore the molecular mechanism of its transmembrane transport.


Assuntos
Toxinas Botulínicas Tipo A , Camundongos , Animais , Toxinas Botulínicas Tipo A/toxicidade , Toxinas Botulínicas Tipo A/química , Toxinas Botulínicas Tipo A/genética , Sorogrupo , Biologia
16.
Environ Microbiol ; 24(1): 50-65, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33973326

RESUMO

Estuaries are depositional environments prone to terrigenous mud sedimentation. While macrofaunal diversity and nitrogen retention are greatly affected by changes in sedimentary mud content, its impact on prokaryotic diversity and nitrogen cycling activity remains understudied. We characterized the composition of estuarine tidal flat prokaryotic communities spanning a habitat range from sandy to muddy sediments, while controlling for salinity and distance. We also determined the diversity, abundance and expression of ammonia oxidizers and N2 O-reducers within these communities by amoA and clade I nosZ gene and transcript analysis. Results show that prokaryotic communities and nitrogen cycling fractions were sensitive to changes in sedimentary mud content, and that changes in the overall community were driven by a small number of phyla. Significant changes occurred in prokaryotic communities and N2 O-reducing fractions with only a 3% increase in mud, while thresholds for ammonia oxidizers were less distinct, suggesting other factors are also important for structuring these guilds. Expression of nitrogen cycling genes was substantially higher in muddier sediments, and results indicate that the potential for coupled nitrification-denitrification became increasingly prevalent as mud content increased. Altogether, results demonstrate that mud content is a strong environmental driver of diversity and N-cycling dynamics in estuarine microbial communities.


Assuntos
Estuários , Microbiota , Salinidade , Archaea/classificação , Bactérias/classificação , Sedimentos Geológicos , Nitrificação , Nitrogênio/metabolismo , Areia
17.
Neurochem Res ; 47(8): 2158-2172, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35661963

RESUMO

Type 2 diabetes (T2DM) is a well known risk factor for Alzheimer's disease. Mitochondria are the center of intracellular energy metabolism and the main source of reactive oxygen species. Mitochondrial dysfunction has been identified as a key factor in diabetes-associated brain alterations contributing to neurodegenerative events. Defective insulin signaling may act in concert with neurodegenerative mechanisms leading to abnormalities in mitochondrial structure and function. Mitochondrial dysfunction triggers neuronal energy exhaustion and oxidative stress, leading to brain neuronal damage and cognitive impairment. The normality of mitochondrial function is basically maintained by mitochondrial quality control mechanisms. In T2DM, defects in the mitochondrial quality control pathway in the brain have been found to lead to mitochondrial dysfunction and cognitive impairment. Here, we discuss the association of mitochondrial dysfunction with T2DM and cognitive impairment. We also review the molecular mechanisms of mitochondrial quality control and impacts of mitochondrial quality control on the progression of cognitive impairment in T2DM.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Diabetes Mellitus Tipo 2 , Doença de Alzheimer/metabolismo , Disfunção Cognitiva/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Mitocôndrias/metabolismo , Estresse Oxidativo/fisiologia , Espécies Reativas de Oxigênio/metabolismo
18.
Cell Biochem Funct ; 40(4): 403-416, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35485606

RESUMO

Ubiquitin-proteasome system (UPS) and autophagy are interconnected proteolysis pathways implicated in doxorubicin resistance of breast cancer cells. Following anticancer treatments, autophagy either plays a cytoprotective role or augments treatment-induced cytotoxicity. However, the role of autophagy in breast cancer cells cotreated with doxorubicin and ixazomib remains unclear. The expression of autophagy proteins (LC3A/B and Beclin-1) and UPS protein (ubiquitin) in MDA-MB-231 and MCF-7 cells following doxorubicin, ixazomib, and/or hydroxychloroquine were determined by western blot. The combinatorial effects and combination index (CI) of triple-combination were determined by cell viability assay and CompuSyn software, respectively. Doxorubicin and ixazomib cotreatment increased Beclin-1 (3.8- and 3.5-fold) and LC3-II expression (13.5- and 1.9-fold) in MDA-MB-231 and MCF-7 cells, respectively. Adding lysosomal inhibitor hydroxychloroquine to doxorubicin and ixazomib further increased LC3-II expression to 45.0- and 16.5-fold in MDA-MB-231 and MCF-7 cells, respectively, confirming autophagy induction. The triple-combination synergistically inhibited cell growth, achieving CI 0.672 and 0.157 in MDA-MB-231 and MCF-7 cells, respectively. The triple-combination also induced ubiquitinated proteins accumulation (2.5-fold and 3.0-fold) in MDA-MB-231 and MCF-7 cells, respectively. These results suggest that the autophagy induced by doxorubicin and ixazomib cotreatment serves cytoprotective role in breast cancer cells. Simultaneous UPS and autophagy inhibition synergistically enhanced doxorubicin-mediated cytotoxicity.


Assuntos
Neoplasias da Mama , Complexo de Endopeptidases do Proteassoma , Apoptose , Autofagia , Proteína Beclina-1/metabolismo , Proteína Beclina-1/farmacologia , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Doxorrubicina/farmacologia , Feminino , Humanos , Hidroxicloroquina/farmacologia , Ubiquitinas
19.
J Reprod Dev ; 68(3): 173-180, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35236789

RESUMO

Long-term hypercaloric diets may adversely affect the development of ovarian follicles. We investigated the effects of high sugar (HS), high fat low sugar (HFLS), and high fat normal sugar (HFNS) diets on the ovarian follicle development in mice fed with these diets as compared to those fed with normal diet (control) for 180 days. Body weight, gonadal fat, glucose, lipid, insulin, estrous cycle, sex hormones and ovarian tissues were examined, and metabolism-related protein expression in the ovaries was evaluated by immunoblotting. The mice fed with hypercaloric diets showed hyperinsulinemia and hyperlipidemia, and exhibited heavier body and gonadal fat weights, longer estrous cycles, and fewer preantral and antral follicles than mice fed with normal diet. The sex hormone levels in the blood were similar to those in controls, except for significantly elevated estradiol levels in the HS diet group. The AMPKα phosphorylation was reduced, while AKT phosphorylation and caspase-3 levels were increased in the ovarian tissues of mice in all three hypercaloric diet groups than those in control. Taken together, the results suggest hyperinsulinemia and hyperlipidemia as possible mechanisms that impair the development of ovarian follicles in response to long-term exposure to unhealthy hypercaloric diets.


Assuntos
Hiperinsulinismo , Hiperlipidemias , Animais , Dieta Hiperlipídica/efeitos adversos , Feminino , Glucose , Hiperinsulinismo/etiologia , Hiperlipidemias/etiologia , Camundongos , Folículo Ovariano/fisiologia
20.
BMC Pulm Med ; 22(1): 434, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36414945

RESUMO

BACKGROUND: Effective-component compatibility of Bufei Yishen formula III (ECC-BYF III) demonstrates positive effects on stable chronic obstructive pulmonary disease (COPD). PURPOSE: To investigate the mechanisms of ECC-BYF III on COPD rats from the aspect of airway epithelial cell senescence. METHODS: COPD model rats (Sprague-Dawley rat) were treated with ECC-BYF III for 8 weeks, and the efficacy was evaluated. Cigarette smoke extract (CSE)-induced senescence model of airway epithelial cells was treated with ECC-BYF III, and related enzymes and proteins involved in oxidative stress and mitophagy were detected. RESULTS: ECC-BYF III markedly rescued pulmonary function and histopathological changes, which might be associated with the amelioration of lung senescence, including the reduction of malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and matrix metalloproteinase (MMP)-9 levels, increase of the level in total superoxide dismutase (T-SOD), and decease in the p21 level in the airways. Furthermore, ECC-BYF III suppressed p16 and p21 expressions and senescence-associated ß-galactosidase (SA-ß-Gal) in CSE-induced airway epithelial cells. Moreover, ECC-BYF III upregulated mitophagy-related proteins, including the co-localizations of TOM20 and LC3B, PINK1 and PARK2, and improved mitochondrial function by upregulating mitochondrial mitofusin (MFN)2 and reducing dynamin-related protein 1 (DRP1) expression. ECC-BYF III enhanced the activities of T-SOD and GSH-PX by up-regulating NRF2, thus inhibiting oxidative stress. After intervention with NRF2 inhibitor, the regulation effects of ECC-BYF III on oxidative stress, mitophagy and senescence in airway epithelial cells were significantly suppressed. CONCLUSIONS: ECC-BYF III exerts beneficial effects on COPD rats by ameliorating airway epithelial cell senescence, which is mediated by inhibiting oxidative stress and subsequently enhancing mitophagy through the activation of NRF2 signaling.


Assuntos
Mitofagia , Doença Pulmonar Obstrutiva Crônica , Ratos , Animais , Fator 2 Relacionado a NF-E2/metabolismo , Ratos Sprague-Dawley , Senescência Celular , Células Epiteliais/metabolismo , Proteínas Quinases/metabolismo , Proteínas Quinases/farmacologia , Superóxido Dismutase/metabolismo
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