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1.
Nature ; 624(7992): 579-585, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38057667

RESUMO

The transfer of photosynthetically produced organic carbon from surface to mesopelagic waters draws carbon dioxide from the atmosphere1. However, current observation-based estimates disagree on the strength of this biological carbon pump (BCP)2. Earth system models (ESMs) also exhibit a large spread of BCP estimates, indicating limited representations of the known carbon export pathways3. Here we use several decades of hydrographic observations to produce a top-down estimate of the strength of the BCP with an inverse biogeochemical model that implicitly accounts for all known export pathways. Our estimate of total organic carbon (TOC) export at 73.4 m (model euphotic zone depth) is 15.00 ± 1.12 Pg C year-1, with only two-thirds reaching 100 m depth owing to rapid remineralization of organic matter in the upper water column. Partitioned by sequestration time below the euphotic zone, τ, the globally integrated organic carbon production rate with τ > 3 months is 11.09 ± 1.02 Pg C year-1, dropping to 8.25 ± 0.30 Pg C year-1 for τ > 1 year, with 81% contributed by the non-advective-diffusive vertical flux owing to sinking particles and vertically migrating zooplankton. Nevertheless, export of organic carbon by mixing and other fluid transport of dissolved matter and suspended particles remains regionally important for meeting the respiratory carbon demand. Furthermore, the temperature dependence of the sequestration efficiency inferred from our inversion suggests that future global warming may intensify the recycling of organic matter in the upper ocean, potentially weakening the BCP.


Assuntos
Dióxido de Carbono , Água do Mar , Água , Animais , Dióxido de Carbono/metabolismo , Fotossíntese , Água do Mar/química , Água/química , Água/metabolismo , Zooplâncton/metabolismo , Aquecimento Global , Oceanos e Mares
2.
Genome Res ; 33(3): 463-477, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37310928

RESUMO

Structural variations (SVs) are a major contributor to genetic diversity and phenotypic variations, but their prevalence and functions in domestic animals are largely unexplored. Here we generated high-quality genome assemblies for 15 individuals from genetically diverse sheep breeds using Pacific Biosciences (PacBio) high-fidelity sequencing, discovering 130.3 Mb nonreference sequences, from which 588 genes were annotated. A total of 149,158 biallelic insertions/deletions, 6531 divergent alleles, and 14,707 multiallelic variations with precise breakpoints were discovered. The SV spectrum is characterized by an excess of derived insertions compared to deletions (94,422 vs. 33,571), suggesting recent active LINE expansions in sheep. Nearly half of the SVs display low to moderate linkage disequilibrium with surrounding single-nucleotide polymorphisms (SNPs) and most SVs cannot be tagged by SNP probes from the widely used ovine 50K SNP chip. We identified 865 population-stratified SVs including 122 SVs possibly derived in the domestication process among 690 individuals from sheep breeds worldwide. A novel 168-bp insertion in the 5' untranslated region (5' UTR) of HOXB13 is found at high frequency in long-tailed sheep. Further genome-wide association study and gene expression analyses suggest that this mutation is causative for the long-tail trait. In summary, we have developed a panel of high-quality de novo assemblies and present a catalog of structural variations in sheep. Our data capture abundant candidate functional variations that were previously unexplored and provide a fundamental resource for understanding trait biology in sheep.


Assuntos
Estudo de Associação Genômica Ampla , Cauda , Animais , Ovinos/genética , Regiões 5' não Traduzidas , Alelos , Fenótipo
3.
J Biol Inorg Chem ; 29(1): 87-99, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38141090

RESUMO

Six aroylhydrazone di-m-chlorobenzyltin complexes {[X-C6H4(O)C=N-N=C(Me)COO](MeOH)(m-Cl-C6H4CH2)2Sn}2 (X = p-Me- (1), p-MeO- (2), p-t-Bu- (3), p-NO2- (4), p-OH- (5) or o-OH- (6)) were synthesized and characterized by HRMS (high-resolution mass spectrometry), NMR (nuclear magnetic resonance spectroscopy), IR (Fourier transform infrared spectroscopy), and TGA (thermogravimetric analysis) techniques. The molecular structure of complexes 1-6 was confirmed by single-crystal X-ray crystallography. The structure of complexes showed a distorted pentagonal bipyramidal configuration around the tin atom center, and the ligands adopted a tridentate chelating mode. Fascinatingly, either one-dimensional infinite chain structures or two-dimensional network structures were observed in the complexes through hydrogen bonds. Complex 2 has the strongest inhibitory effect on MCF7 and HepG2 cell proliferation, its effect was superior to that of the positive control drug cisplatin. The interaction of ct-DNA (calf-thymus DNA) with complex 2 was explored using UV absorption (ultraviolet absorption) and fluorescence spectroscopy. Complex 2 exhibited a moderate affinity for ct-DNA through intercalation modes. The interaction of complex 2 with ct-DNA has also been supported by molecular docking studies.


Assuntos
Complexos de Coordenação , DNA , Hidróxidos , Simulação de Acoplamento Molecular , Estrutura Molecular , Espectroscopia de Ressonância Magnética , DNA/química , Cristalografia por Raios X , Complexos de Coordenação/química , Ligantes
4.
Helicobacter ; 29(2): e13072, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38686467

RESUMO

BACKGROUND: Helicobacter pylori infection is one of the main causes of gastric cancer. thioredoxin-1 (Trx1) and arginase (RocF) expressed by H. pylori were found to be closely related to its pathogenicity. However, whether Trx1 and RocF can be used in clinical screening of highly pathogenic H. pylori and the pathogenesis of trx1 high expressing H. pylori remain still unknown. MATERIALS AND METHODS: We investigated the expression level of H. pylori trx1 and H. pylori rocF in human gastric antrum tissues using reverse transcription and quantitative real-time PCR (RT-qPCR) and clarified the clinical application value of trx1 and rocF for screening highly pathogenic H. pylori. The pathogenic mechanism of Trx1 were further explored by RNA-seq of GES-1 cells co-cultured with trx1 high or low expressing H. pylori. Differentially expressed genes and signaling pathways were validated by RT-qPCR, Enzyme-linked immunosorbent assay (ELISA), western blot, immunohistochemistry and immunofluorescence. We also assessed the adherence of trx1 high and low expressing H. pylori to GES-1 cells. RESULTS: We found that H. pylori trx1 and H. pylori rocF were more significantly expressed in the gastric cancer and peptic ulcer group than that in the gastritis group and the parallel diagnosis of H. pylori trx1 and H. pylori rocF had high sensitivity. The trx1 high expressing H. pylori had stronger adhesion ability to GES-1 cells and upregulated the interleukin (IL) 23A/nuclear factor κappaB (NF-κB)/IL17A, IL6, IL8 pathway. CONCLUSIONS: H. pylori trx1 and H. pylori rocF can be used in clinical screening of highly pathogenic H. pylori and predicting the outcome of H. pylori infection. The trx1 high expressing H. pylori has stronger adhesion capacity and promotes the development of gastric diseases by upregulating the activation of NF-κB signaling pathway.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Interleucina-8 , NF-kappa B , Tiorredoxinas , Humanos , Helicobacter pylori/genética , Helicobacter pylori/fisiologia , Helicobacter pylori/patogenicidade , Tiorredoxinas/metabolismo , Tiorredoxinas/genética , NF-kappa B/metabolismo , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/metabolismo , Interleucina-8/metabolismo , Interleucina-8/genética , Regulação para Cima , Transdução de Sinais , Arginase/metabolismo , Arginase/genética , Linhagem Celular , Gastropatias/microbiologia , Gastropatias/metabolismo , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia
5.
Nucleic Acids Res ; 50(D1): D1091-D1099, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34643708

RESUMO

Ruminant Genome Database (RGD; http://animal.nwsuaf.edu.cn/RGD) provides visualization and analysis tools for ruminant comparative genomics and functional annotations. As more high-quality ruminant genome assemblies have become available, we have redesigned the user interface, integrated and expanded multi-omics data, and developed novel features to improve the database. The new version, RGD v2.0, houses 78 ruminant genomes; 110-species synteny alignments for major livestock (including cattle, sheep, goat) and wild ungulates; 21 012 orthologous gene clusters with Gene Ontology and pathway annotation; ∼8 600 000 conserved elements; and ∼1 000 000 cis-regulatory elements by utilizing 1053 epigenomic data sets. The transcriptome data in RGD v2.0 has nearly doubled, currently with 1936 RNA-seq data sets, and 155 174 phenotypic data sets have been newly added. New and updated features include: (i) The UCSC Genome Browser, BLAT, BLAST and Table Browser tools were updated for six available ruminant livestock species. (ii) The LiftOver tool was newly introduced into our browser to allow coordinate conversion between different ruminant assemblies. And (iii) tissue specificity index, tau, was calculated to facilitate batch screening of specifically expressed genes. The enhanced genome annotations and improved functionality in RGD v2.0 will be useful for study of genome evolution, environmental adaption, livestock breeding and biomedicine.


Assuntos
Bases de Dados Genéticas , Sequências Reguladoras de Ácido Nucleico/genética , Ruminantes/genética , Software , Animais , Bovinos , Genômica , Cabras/classificação , Cabras/genética , Internet , Anotação de Sequência Molecular , Ovinos/classificação , Ovinos/genética
6.
Mol Biol Evol ; 39(4)2022 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-35325213

RESUMO

The gene numbers and evolutionary rates of birds were assumed to be much lower than those of mammals, which is in sharp contrast to the huge species number and morphological diversity of birds. It is, therefore, necessary to construct a complete avian genome and analyze its evolution. We constructed a chicken pan-genome from 20 de novo assembled genomes with high sequencing depth, and identified 1,335 protein-coding genes and 3,011 long noncoding RNAs not found in GRCg6a. The majority of these novel genes were detected across most individuals of the examined transcriptomes but were seldomly measured in each of the DNA sequencing data regardless of Illumina or PacBio technology. Furthermore, different from previous pan-genome models, most of these novel genes were overrepresented on chromosomal subtelomeric regions and microchromosomes, surrounded by extremely high proportions of tandem repeats, which strongly blocks DNA sequencing. These hidden genes were proved to be shared by all chicken genomes, included many housekeeping genes, and enriched in immune pathways. Comparative genomics revealed the novel genes had 3-fold elevated substitution rates than known ones, updating the knowledge about evolutionary rates in birds. Our study provides a framework for constructing a better chicken genome, which will contribute toward the understanding of avian evolution and the improvement of poultry breeding.


Assuntos
Galinhas , Genoma , Animais , Galinhas/genética , Genômica , Mamíferos/genética , Análise de Sequência de DNA
7.
J Sleep Res ; 32(3): e13797, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36528854

RESUMO

Sleep loss with work overload can impact human cognitive performance. However, the brain's response to an increased working memory load following total sleep deprivation (TSD) remains unclear. In the present study, we focussed on the dynamic response of the hippocampus to increased working memory load before and after total sleep deprivation of 36 h. A total of 16 male participants completed a verbal working memory task under functional magnetic resonance imaging. After whole-brain activation analysis and region of interest analysis of the hippocampus, the generalised form of context-dependent psychophysiological interactions (gPPI) was used to analyse the hippocampal functional connectivity with the whole brain. The results revealed that as the working memory load increased within a small range, from 0-back to 1-back task, the left hippocampal functional connectivity decreased with the left supplementary motor area, left pars opercularis, left rolandic operculum, right superior frontal gyrus, bilateral precentral gyrus, and left middle cingulate cortex following total sleep deprivation compared with that observed in resting wakefulness. When the working memory load further increased from 1-back to 2-back task, the connectivity increased between the left hippocampus and the left superior parietal lobule as well as between the left hippocampus and right lingual gyrus after total sleep deprivation compared with that observed in resting wakefulness. Moreover, the left hippocampus gPPI effect on the left middle cingulate cortex and left superior parietal lobule could predict the behavioural test accuracy in 1-back and 2-back task, respectively, following total sleep deprivation. These findings indicated that increased working memory load after total sleep deprivation disrupts working memory processes. The brain reacts to these disruptions in a dynamic and flexible manner, involving not only brain activation but also hippocampus-related functional network connections.


Assuntos
Memória de Curto Prazo , Privação do Sono , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Encéfalo , Hipocampo , Córtex Pré-Frontal , Imageamento por Ressonância Magnética/métodos , Mapeamento Encefálico
8.
Helicobacter ; 28(4): e12999, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37382029

RESUMO

BACKGROUND: The B7 protein family is one of the most important immune checkpoint proteins. Gastric cancer (GC) is the fourth most common cause of cancer-related mortality worldwide and shows a significant correlation with the B7 family in tumorigenesis and progression. Helicobacter pylori infection is the most important risk factor promoting the progression of gastric precancerous lesions and GC, which also affects the expression of B7 family members. We aimed to systematically summarize and review current studies on the expression and function of B7 family members during H. pylori infection in precancerous gastric lesions and GC. MATERIALS AND METHODS: PubMed was searched for the relationship between B7 family, H. pylori and gastric carcinogenesis until April 5, 2023. Different permutation and combination of the search terms, including "H. pylori," "Helicobacter pylori," "B7," "gastric cancer," and "gastric precancerous lesions," all the different names of specific B7 molecules, and the names of signaling pathways were used. Literature related to our research topic was selected and summarized. RESULTS: The B7 family participates in gastric carcinogenesis through certain immune signaling pathways by binding to their receptors and exhibiting co-inhibitory or co-stimulatory effects. Targeting the B7 family members with mAbs may be a promising therapeutic strategy for treating gastric diseases. CONCLUSIONS: A thorough understanding of the role of B7 molecules during H. pylori infection and GC progression is helpful for the treatment and prevention of GC and the prediction of H. pylori infection outcomes, providing evidence for H. pylori eradication.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Lesões Pré-Cancerosas , Neoplasias Gástricas , Humanos , Infecções por Helicobacter/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Carcinogênese/genética , Carcinogênese/patologia , Lesões Pré-Cancerosas/patologia , Antígenos B7/farmacologia , Mucosa Gástrica/patologia
9.
Laterality ; 28(1): 32-47, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36859828

RESUMO

The golden snub-nosed monkey (Rhinopithecus roxellana) is a typical arboreal group-living Old World primate. While limb preference has been extensively studied in this species, limb preference consistency has not yet been explored. Here, based on 26 R. roxellana adults, we investigated whether individuals exhibit consistent motor biases in manual- (e.g., unimanual feeding and social grooming) and foot-related (e.g., bipedal locomotion) tasks and whether limb preference consistency is influenced by increased social interactions during social grooming. Results showed no consistency in the direction or strength of limb preference among tasks, except for lateral strength in handedness for unimanual feeding and footedness in the initiation of locomotion. Population-level foot preference was only found among right-handers. Marked lateral bias was found in unimanual feeding, indicating that it may be a sensitive behavioural measure for assessing manual preference, especially for provisioned populations. This study not only improves our understanding of the relationship between hand and foot preference in R. roxellana but also reveals potential differential hemispheric regulation of limb preference and the influence of increased social interaction on handedness consistency.


Assuntos
Presbytini , Animais , Asseio Animal , Lateralidade Funcional , Locomoção
10.
BMC Genomics ; 23(1): 364, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35549894

RESUMO

BACKGROUND: Multi-omics data can provide a stereoscopic view to explore potential causal variations and genes, as well as underlying genetic mechanisms of complex traits. However, for many non-mammalian species, including chickens, these resources are poorly integrated and reused, greatly limiting genetic research and breeding processes of the species. RESULTS: Here, we constructed Galbase, an easily accessible repository that integrates public chicken multi-omics data from 928 re-sequenced genomes, 429 transcriptomes, 379 epigenomes, 15,275 QTL entries, and 7,526 associations. A total of 21.67 million SNPs, 2.71 million InDels, and 488,583 cis-regulatory elements were included. Galbase allows users to retrieve genomic variations in geographical maps, gene expression profiling in heatmaps, and epigenomic signals in peak patterns. It also provides modules for batch annotation of genes, regions, and loci based on multi-layered omics data. Additionally, a series of convenient tools, including the UCSC Genome Browser, WashU Epigenome Browser, BLAT, BLAST, and LiftOver, were also integrated to facilitate search, visualization, and analysis of sequence features. CONCLUSION: Galbase grants new opportunities to research communities to undertake in-depth functional genomic studies on chicken. All features of Galbase make it a useful resource to identify genetic variations responsible for chicken complex traits. Galbase is publicly available at http://animal.nwsuaf.edu.cn/ChickenVar .


Assuntos
Galinhas , Genômica , Animais , Galinhas/genética , Bases de Dados Genéticas , Genoma , Sequências Reguladoras de Ácido Nucleico , Software
11.
Mol Carcinog ; 61(3): 334-345, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34818445

RESUMO

Current advancements in prostate cancer (PC) therapies have been successful in slowing PC progression and increasing life expectancy; however, there is still no curative treatment for advanced metastatic castration resistant PC (mCRPC). Most treatment options target the androgen receptor, to which many PCs eventually develop resistance. Thus, there is a dire need to identify and validate new molecular targets for treating PC. We found NUAK family kinase 2 (NUAK2) expression is elevated in PC and mCRPC versus normal tissue, and expression correlates with an increased risk of metastasis. Given this observation and because NUAK2, as a kinase, is actionable, we evaluated the potential of NUAK2 as a molecular target for PC. NUAK2 is a stress response kinase that also plays a role in activation of the YAP cotranscriptional oncogene. Combining pharmacological and genetic methods for modulating NUAK2, we found that targeting NUAK2 in vitro leads to reduction in proliferation, three-dimensional tumor spheroid growth, and matrigel invasion of PC cells. Differential gene expression analysis of PC cells treated NUAK2 small molecule inhibitor HTH-02-006 demonstrated that NUAK2 inhibition results in downregulation of E2F, EMT, and MYC hallmark gene sets after NUAK2 inhibition. In a syngeneic allograft model and in radical prostatectomy patient derived explants, NUAK2 inhibition slowed tumor growth and proliferation rates. Mechanistically, HTH-02-006 treatment led to inactivation of YAP and the downregulation of NUAK2 and MYC protein levels. Our results suggest that NUAK2 represents a novel actionable molecular target for PC that warrants further exploration.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Proteínas Serina-Treonina Quinases
12.
Biomed Eng Online ; 21(1): 55, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35941613

RESUMO

BACKGROUND: Refractive error detection is a significant factor in preventing the development of myopia. To improve the efficiency and accuracy of refractive error detection, a refractive error detection network (REDNet) is proposed that combines the advantages of a convolutional neural network (CNN) and a recurrent neural network (RNN). It not only extracts the features of each image, but also fully utilizes the sequential relationship between images. In this article, we develop a system to predict the spherical power, cylindrical power, and spherical equivalent in multiple eccentric photorefraction images. Approach First, images of the pupil area are extracted from multiple eccentric photorefraction images; then, the features of each pupil image are extracted using the REDNet convolution layers. Finally, the features are fused by the recurrent layers in REDNet to predict the spherical power, cylindrical power, and spherical equivalent. RESULTS: The results show that the mean absolute error (MAE) values of the spherical power, cylindrical power, and spherical equivalent can reach 0.1740 D (diopters), 0.0702 D, and 0.1835 D, respectively. SIGNIFICANCE: This method demonstrates a much higher accuracy than those of current state-of-the-art deep-learning methods. Moreover, it is effective and practical.


Assuntos
Aprendizado Profundo , Miopia , Erros de Refração , Humanos , Redes Neurais de Computação , Refração Ocular , Erros de Refração/diagnóstico
13.
Zhongguo Yi Liao Qi Xie Za Zhi ; 46(4): 377-381, 2022 Jul 30.
Artigo em Zh | MEDLINE | ID: mdl-35929150

RESUMO

In order to better assist doctors in the diagnosis of dry eye and improve the ability of ophthalmologists to recognize the condition of meibomian gland, a meibomian gland image segmentation and enhancement method based on Mobile-U-Net network was proposed. Firstly, Mobile-Net is used as the coding part of U-Net for down sampling, and then features are extracted and fused with the features in decoder to guide image segmentation. Secondly, the segmentation of meibomian gland region is enhanced to assist doctors to judge the condition. Thirdly, a large number of meibomian gland images are collected to train and verify the semantic segmentation network, and the clarity evaluation index is used to verify the meibomian gland enhancement effect. The experimental results show that the similarity coefficient of the proposed method is stable at 92.71%, and the image clarity index is better than the similar dry eye detection instruments on the market.


Assuntos
Aprendizado Profundo , Síndromes do Olho Seco , Diagnóstico por Imagem , Humanos , Processamento de Imagem Assistida por Computador , Glândulas Tarsais/diagnóstico por imagem
14.
Mol Biol Evol ; 37(7): 2099-2109, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32324877

RESUMO

Goats are one of the most widespread farmed animals across the world; however, their migration route to East Asia and local evolutionary history remain poorly understood. Here, we sequenced 27 ancient Chinese goat genomes dating from the Late Neolithic period to the Iron Age. We found close genetic affinities between ancient and modern Chinese goats, demonstrating their genetic continuity. We found that Chinese goats originated from the eastern regions around the Fertile Crescent, and we estimated that the ancestors of Chinese goats diverged from this population in the Chalcolithic period. Modern Chinese goats were divided into a northern and a southern group, coinciding with the most prominent climatic division in China, and two genes related to hair follicle development, FGF5 and EDA2R, were highly divergent between these populations. We identified a likely causal de novo deletion near FGF5 in northern Chinese goats that increased to high frequency over time, whereas EDA2R harbored standing variation dating to the Neolithic. Our findings add to our understanding of the genetic composition and local evolutionary process of Chinese goats.


Assuntos
Evolução Biológica , DNA Antigo/química , Genoma , Cabras/genética , Adaptação Biológica , Animais , China , Seleção Genética
15.
J Exp Biol ; 224(Pt 2)2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-33443047

RESUMO

We previously showed that different skeletal muscles in Daurian ground squirrels (Spermophilus dauricus) possess different antioxidant strategies during hibernation; however, the reason for these varied strategies remains unclear. To clarify this issue, we studied REDD1, FOXO4, PGC-1α, FOXO1 and atrogin-1 proteins to determine the potential cause of the different antioxidant strategies in Daurian ground squirrels during hibernation, and to clarify whether different strategies affect atrophy-related signals. Results showed that the soleus (SOL) muscle experienced intracellular hypoxia during interbout arousal, but no oxidative stress. This may be due to increased PGC-1α expression enhancing antioxidant capacity in the SOL under hypoxic conditions. Extensor digitorum longus (EDL) muscle showed no change in oxidative stress, hypoxia or antioxidant capacity during hibernation. The FOXO1 and PGC-1α results strongly suggested differentially regulated fuel metabolism in the SOL and EDL muscles during hibernation, i.e. enhanced lipid oxidation and maintained anaerobic glycolysis, respectively. Atrogin-1 expression did not increase during hibernation in either the SOL or EDL, indicating that protein synthesis was not inhibited by atrogin-1. Thus, our results suggest that different fuel regulation may be one mechanism related to antioxidant defense strategy formation in different kinds of skeletal muscle fibers of Daurian ground squirrels during hibernation.


Assuntos
Hibernação , Animais , Antioxidantes , Fibras Musculares Esqueléticas , Músculo Esquelético , Sciuridae
16.
Laterality ; 26(1-2): 201-212, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33616011

RESUMO

Behavioural laterality in nonhuman primates has been commonly studied in paired limb organs, and studies in unpaired organs such as tails are less common. The very limited investigations on tail laterality have focused on New World primates. We firstly investigated the lateral bias of tail wrapping in an Old World primate. From a wild group of one hundred of golden snub-nosed monkeys (Rhinopithecus roxellana), 14 adult monkeys, 7 males and 7 females, were chosen as focus animals. The data of tail wrapping in two different postures that were resting on the ground and climbing the tree trunk were collected and analyzed. The results demonstrated (1) that, when resting on the ground, the focus animals, 3 showed right-side tail-wrapping preference and 11 were ambipreferent; (2) that there was a population-level right tail-wrapping preference in climbing, and 9 of them showed right-side preference, 1 left-side preference and 4 were ambipreferent; (3) and that there were no significant sex differences on the direction and strength of tail wrapping laterality. These findings provide significant evidence for a difference of cerebral asymmetries in tail-wrapping control and would be valuable for further understanding the important function of tails in Old World primates.


Assuntos
Colobinae , Presbytini , Animais , Feminino , Lateralidade Funcional , Masculino , Postura
17.
J Exp Biol ; 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34005794

RESUMO

We previously showed that different skeletal muscles in Daurian ground squirrels (Spermophilus dauricus) possess different antioxidant strategies during hibernation; however, the reason for these varied strategies remains unclear. To clarify this issue, we studied REDD1, FOXO4, PGC-1α, FOXO1, and atrogin-1 proteins to determine the potential cause of the different antioxidant strategies in Daurian ground squirrels during hibernation, and to clarify whether different strategies affect atrophy-related signals. Results showed that the soleus (SOL) muscle experienced intracellular hypoxia during interbout arousal, but no oxidative stress. This may be due to increased PGC-1α expression enhancing antioxidant capacity in the SOL under hypoxic conditions. Extensor digitorum longus (EDL) muscle showed no change in oxidative stress, hypoxia, or antioxidant capacity during hibernation. The FOXO1 and PGC-1α results strongly suggested differentially regulated fuel metabolism in the SOL and EDL muscles during hibernation, i.e., enhanced lipid oxidation and maintained anaerobic glycolysis, respectively. Atrogin-1 expression did not increase during hibernation in either the SOL or EDL, indicating that protein synthesis was not inhibited by atrogin-1. Thus, our results suggest that different fuel regulation may be one mechanism related to antioxidant defense strategy formation in different kinds of skeletal muscle fibers of Daurian ground squirrels during hibernation.

18.
Angew Chem Int Ed Engl ; 59(52): 23791-23799, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-32949090

RESUMO

Non-metal-based single-atom catalysts (SACs) offer low cost, simple synthesis methods, and effective regulation for substrates. Herein, we developed a simplified pressurized gas-assisted process, and report the first non-metal single-atom phosphorus with atomic-level dispersion on unique single-crystal Mo2 C hexagonal nanosheet arrays with a (001) plane supported by carbon sheet (SAP-Mo2 C-CS). The SAP-Mo2 C-CS is structurally stable and shows exceptional electrocatalytic activity for the hydrogen evolution reaction (HER). A so-called high-active "window" based on the active sites of P atoms and their adjacent Mo atoms gives a ΔGH* close to zero for hydrogen evolution, which is the most ideal ΔGH* reported so far. Meanwhile, the moderate d-band center value of SAP-Mo2 C-CS can be also used as an ideal standard value to evaluate the HER performance in non-metal-based SACs.

19.
Angew Chem Int Ed Engl ; 58(49): 17709-17717, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31476103

RESUMO

Maximizing the activity of materials towards the alkaline hydrogen evolution reaction while maintaining their structural stability under realistic working conditions remains an area of active research. Herein, we report the first controllable surface modification of graphene(G)/V8 C7 heterostructures by nitrogen. Because the introduced N atoms couple electronically with V atoms, the V sites can reduce the energy barrier for water adsorption and dissociation. Investigation of the multi-regional synergistic catalysis on N-modified G/V8 C7 by experimental observations and density-functional-theory calculations reveals that the increase of electron density on the epitaxial graphene enable it to become favorable for H* adsorption and the subsequent reaction with another H2 O molecule. This work extends the range of surface-engineering approaches to optimize the intrinsic properties of materials and could be generalized to the surface modification of other transition-metal carbides.

20.
J Cell Physiol ; 233(11): 8711-8722, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29761850

RESUMO

As a typical hibernator, the Daurian ground squirrel (Spermophilus dauricus) spends considerable time in a state of reduced activity with prolonged fasting. Despite this, they experience little muscle atrophy and have thus become an interesting anti-disuse muscle atrophy model. The IKKß/NF-κB signaling pathway is significant to muscle atrophy due to the protein degradation resulting from the upregulation of the E3 ubiquitin ligase MuRF1. The current study showed that the IKKß/NF-κB signaling pathway and MuRF1 maintained relatively steady mRNA and protein expression levels, with little muscle atrophy observed in the soleus (slow-twitch, SOL) or extensor digitorum longus (fast-twitch, EDL) during hibernation (HIB); however, mRNA expression significantly increased in the SOL and EDL muscle during interbout arousal (IBA), as did the MuRF1 mRNA level in the SOL and MuRF1 protein level in the EDL. Interestingly, the expressions of p50 and MuRF1 significantly increased during HIB in the gastrocnemius (mixed muscle, GAS) and showed moderate atrophy, but dramatically decreased during IBA. Elevated IKKß and p50 mRNA and protein expression in the cardiac muscle (CM) during HIB did not accompany increased MuRF1 expression or muscle wasting. Importantly, almost all increased or decreased indicators in the tested tissues recovered to pre-hibernation levels after HIB. This is the first study to report on the unexpected regulation of the IKKß/NF-κB/MuRF1 pathway with remarkable muscle plasticity in Daurian ground squirrels during hibernation. Furthermore, we found that different types of muscles exhibited different strategies to cope with prolonged hibernation-induced disuse muscle atrophy.


Assuntos
Quinase I-kappa B/genética , Proteínas Musculares/genética , Músculo Esquelético/crescimento & desenvolvimento , Animais , Regulação da Expressão Gênica no Desenvolvimento , Músculo Esquelético/metabolismo , NF-kappa B/genética , Sciuridae/genética , Sciuridae/fisiologia
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