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1.
Mol Cell ; 77(2): 368-383.e7, 2020 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-31677973

RESUMO

Interphase chromatin is hierarchically organized into higher-order architectures that are essential for gene functions, yet the biomolecules that regulate these 3D architectures remain poorly understood. Here, we show that scaffold attachment factor B (SAFB), a nuclear matrix (NM)-associated protein with RNA-binding functions, modulates chromatin condensation and stabilizes heterochromatin foci in mouse cells. SAFB interacts via its R/G-rich region with heterochromatin-associated repeat transcripts such as major satellite RNAs, which promote the phase separation driven by SAFB. Depletion of SAFB leads to changes in 3D genome organization, including an increase in interchromosomal interactions adjacent to pericentromeric heterochromatin and a decrease in genomic compartmentalization, which could result from the decondensation of pericentromeric heterochromatin. Collectively, we reveal the integrated roles of NM-associated proteins and repeat RNAs in the 3D organization of heterochromatin, which may shed light on the molecular mechanisms of nuclear architecture organization.


Assuntos
Heterocromatina/genética , Proteínas de Ligação à Região de Interação com a Matriz/genética , Proteínas Associadas à Matriz Nuclear/genética , RNA Satélite/genética , Receptores de Estrogênio/genética , Animais , Linhagem Celular , Cromatina/genética , Genoma/genética , Humanos , Camundongos
2.
EMBO Rep ; 24(8): e57550, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37381832

RESUMO

Long interspersed nuclear elements (LINEs) play essential roles in shaping chromatin states, while the factors that cooperate with LINEs and their roles in higher-order chromatin organization remain poorly understood. Here, we show that MATR3, a nuclear matrix protein, interplays with antisense LINE1 (AS L1) RNAs to form a meshwork via phase separation, providing a dynamic platform for chromatin spatial organization. MATR3 and AS L1 RNAs affect the nuclear localization of each other. After MATR3 depletion, the chromatin, particularly H3K27me3-modified chromatin, redistributes in the cell nuclei. Topologically associating domains (TADs) that highly transcribe MATR3-associated AS L1 RNAs show decreased intra-TAD interactions in both AML12 and ES cells. MATR3 depletion increases the accessibility of H3K27me3 domains adjacent to MATR3-associated AS L1, without affecting H3K27me3 modifications. Furthermore, amyotrophic lateral sclerosis (ALS)-associated MATR3 mutants alter biophysical features of the MATR3-AS L1 RNA meshwork and cause an abnormal H3K27me3 staining. Collectively, we reveal a role of the meshwork formed by MATR3 and AS L1 RNAs in gathering chromatin in the nucleus.


Assuntos
Esclerose Lateral Amiotrófica , RNA Antissenso , Humanos , Histonas/genética , Esclerose Lateral Amiotrófica/genética , Cromatina/genética , Núcleo Celular/genética , Núcleo Celular/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas Associadas à Matriz Nuclear/genética , Proteínas Associadas à Matriz Nuclear/metabolismo
3.
Cereb Cortex ; 34(3)2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38511722

RESUMO

Neurovascular decoupling plays a significant role in dysfunction following an ischemic stroke. This study aimed to explore the effect of low- and high-frequency repetitive transcranial magnetic stimulation on neurovascular remodeling after ischemic stroke. To achieve this goal, we compared functional hyperemia, cerebral blood flow regulatory factors, and neurochemical transmitters in the peri-infract cortex 21 days after a photothrombotic stroke. Our findings revealed that low- and high-frequency repetitive transcranial magnetic stimulation increased the real-time cerebral blood flow in healthy mice and improved neurobehavioral outcomes after stroke. Furthermore, high-frequency (5-Hz) repetitive transcranial magnetic stimulation revealed stronger functional hyperemia recovery and increased the levels of post-synaptic density 95, neuronal nitric oxide synthase, phosphorylated-endothelial nitric oxide synthase, and vascular endothelial growth factor in the peri-infract cortex compared with low-frequency (1-Hz) repetitive transcranial magnetic stimulation. The magnetic resonance spectroscopy data showed that low- and high-frequency repetitive transcranial magnetic stimulation reduced neuronal injury and maintained excitation/inhibition balance. However, 5-Hz repetitive transcranial magnetic stimulation showed more significant regulation of excitatory and inhibitory neurotransmitters after stroke than 1-Hz repetitive transcranial magnetic stimulation. These results indicated that high-frequency repetitive transcranial magnetic stimulation could more effectively promote neurovascular remodeling after stroke, and specific repetitive transcranial magnetic stimulation frequencies might be used to selectively regulate the neurovascular unit.


Assuntos
Hiperemia , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Camundongos , Estimulação Magnética Transcraniana/métodos , Fator A de Crescimento do Endotélio Vascular , Resultado do Tratamento
4.
Anal Chem ; 96(18): 7030-7037, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38656919

RESUMO

Intracellular cancer-related biomarker imaging strategy has been used for specific identification of cancer cells, which was of great importance to accurate cancer clinical diagnosis and prognosis studies. Localized DNA circuits with improved sensitivity showed great potential for intracellular biomarkers imaging. However, the ability of localized DNA circuits to specifically image cancer cells is limited by off-site signal leakage associated with a single-biomarker sensing strategy. Herein, we integrated the endogenous enzyme-powered strategy with logic-responsive and localized signal amplifying capability to construct a self-assembled endogenously AND logic DNA nanomachine (EDN) for highly specific cancer cell imaging. When the EDN encountered a cancer cell, the overexpressed DNA repairing enzyme apurinic/apyrimidinic endonuclease 1 (APE1) and miR-21 could synergistically activate a DNA circuit via cascaded localized toehold-mediated strand displacement (TMSD) reactions, resulting in amplified fluorescence resonance energy transfer (FRET) signal. In this strategy, both endogenous APE1 and miR-21, served as two "keys" to activate the AND logic operation in cancer cells to reduce off-tumor signal leakage. Such a multiplied molecular recognition/activation nanomachine as a powerful toolbox realized specific capture and reliable imaging of biomolecules in living cancer cells.


Assuntos
DNA Liase (Sítios Apurínicos ou Apirimidínicos) , DNA , Transferência Ressonante de Energia de Fluorescência , MicroRNAs , Humanos , MicroRNAs/análise , MicroRNAs/metabolismo , DNA/química , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Neoplasias/diagnóstico por imagem , Imagem Óptica
5.
Biochem Biophys Res Commun ; 711: 149934, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38626621

RESUMO

C-terminally encoded peptides (CEPs) are peptide hormones that function as mobile signals coordinating crucial developmental programs in plants. Previous studies have revealed that CEPs exert negative regulation on root development through interaction with CEP receptors (CEPRs), CEP DOWNSTREAMs (CEPDs), the cytokinin receptor ARABIDOPSIS HISTIDINE KINASE (AHKs) and the transcriptional repressor Auxin/Indole-3-Acetic Acid (AUX/IAA). However, the precise molecular mechanisms underlying CEPs-mediated regulation of root development via auxin and cytokinin signaling pathways still necessitate further detailed investigation. In this study, we examined prior research and elucidated the underlying molecular mechanisms. The results showed that both synthetic AtCEPs and overexpression of AtCEP5 markedly supressed primary root elongation and lateral root (LR) formation in Arabidopsis. Molecular biology and genetics elucidated how CEPs inhibit root growth by suppressing auxin signaling while promoting cytokinin signaling. In summary, this study elucidated the inhibitory effects of AtCEPs on Arabidopsis root growth and provided insights into their potential molecular mechanisms, thus enhancing our comprehension of CEP-mediated regulation of plant growth and development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Citocininas , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Raízes de Plantas , Transdução de Sinais , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Arabidopsis/genética , Citocininas/metabolismo , Ácidos Indolacéticos/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Reguladores de Crescimento de Plantas/metabolismo , Hormônios Peptídicos/metabolismo , Hormônios Peptídicos/genética
6.
Phys Rev Lett ; 132(11): 117401, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38563954

RESUMO

When studying interacting systems, computing their statistical properties is a fundamental problem in various fields such as physics, applied mathematics, and machine learning. However, this task can be quite challenging due to the exponential growth of the state space as the system size increases. Many standard methods have significant weaknesses. For instance, message-passing algorithms can be inaccurate and even fail to converge due to short loops, while tensor network methods can have exponential computational complexity in large graphs due to long loops. In this Letter, we propose a new method called "tensor network message passing." This approach allows us to compute local observables like marginal probabilities and correlations by combining the strengths of tensor networks in contracting small subgraphs with many short loops and the strengths of message-passing methods in globally sparse graphs, thus addressing the crucial weaknesses of both approaches. Our algorithm is exact for systems that are globally treelike and locally dense-connected when the dense local graphs have a limited tree width. We have conducted numerical experiments on synthetic and real-world graphs to compute magnetizations of Ising models and spin glasses, and have demonstrated the superiority of our approach over standard belief propagation and the recently proposed loopy message-passing algorithm. In addition, we discuss the potential applications of our method in inference problems in networks, combinatorial optimization problems, and decoding problems in quantum error correction.

7.
Immunity ; 42(5): 953-964, 2015 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-25992864

RESUMO

Defining specific cellular and molecular mechanisms in most obesity-related diseases remains an important challenge. Here we report a serendipitous finding that consumption of a high-fat diet (HFD) greatly increased the occurrence of skin lesions in C57BL/6 mice. We demonstrated that HFD induced the accumulation of a specific type of CD11c(+) macrophages in skin preceding detectable lesions. These cells primed skin to induce IL-1ß and IL-18 signaling, which further promoted the cytokines IFN-γ- and IL-17-mediated skin inflammation. Mechanistically, epidermal fatty acid binding protein (E-FABP) was significantly upregulated in skin of obese mice, which coupled lipid droplet formation and NLRP3 inflammasome activation. Deficiency of E-FABP in obese mice decreased recruitment of CD11c(+) macrophages in skin tissues, reduced production of IL-1ß and IL-18, and consequently dampened activation of effector T cells. Furthermore, E-FABP-deficient mice are completely resistant to HFD-induced skin lesions. Collectively, E-FABP represents a molecular sensor triggering HFD-induced skin inflammation.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Proteínas de Ligação a Ácido Graxo/metabolismo , Inflamação/etiologia , Proteínas de Neoplasias/metabolismo , Dermatopatias/imunologia , Animais , Citocinas/metabolismo , Proteínas de Ligação a Ácido Graxo/deficiência , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/imunologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Neoplasias/deficiência , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/imunologia , Dermatopatias/genética , Linfócitos T/imunologia
8.
Purinergic Signal ; 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38642324

RESUMO

In clinical practice, depression and anxiety frequently coexist, and they are both comorbid with somatic diseases. The P2X7R is an adenosine 5'-triphosphate (ATP)-gated non-selective cation channel that is widely expressed in immune-related cells. Under conditions of stress, chronic pain, and comorbid chronic physical illness, P2X7R activation in glial cells leads to neuroinflammation. This could contribute to the development of anxiety and depression-related emotional disturbances. Previous studies have shown that the P2X7 receptor (P2X7R) plays an important role in the pathogenesis of both anxiety and depression. Thus, the P2X7R may play a role in the comorbidity of anxiety and depression. Positron emission tomography can be used to assess the degree and location of neuroinflammation by monitoring functional and expression-related changes in P2X7R, which can facilitate clinical diagnoses and guide the treatment of patients with anxiety and depression. Moreover, single nucleotide polymorphisms (SNPs) in the P2X7R gene are associated with susceptibility to different types of psychiatric disorders. Thus, evaluating the SNPs of the P2X7R gene could enable personalized mood disorder diagnoses and treatments. If the P2X7R were set as a therapeutic target, selective P2X7R antagonists may modulate P2X7R function, thereby altering the balance of intra- and extra-cellular ATP. This could have therapeutic implications for treating anxiety and depression, as well as for pain management. According to in vitro and in vivo studies, the P2X7R plays an important role in anxiety and depression. In this review, we consider the potential of the P2X7R as a therapeutic target for comorbid anxiety and depression, and discuss the potential diagnostic and therapeutic value of this receptor.

9.
Appl Microbiol Biotechnol ; 108(1): 330, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730049

RESUMO

A more optimized culture medium used in vitro to mimic the bacterial composition of original oral flora as similar as possible remains difficult at present, and the goal of this study is to develop a novel oral biofilm medium to restore the original oral microbiome. Firstly, we conducted a systematic literature review by searching PubMed and summarized the current reported culture media in vitro. Seven culture media were found. We used mixed saliva as the origin of oral species to compare the effects of the above media in culturing oral multispecies biofilms. Results indicated that among the seven media brain heart infusion containing 1% sucrose (BHIs) medium, PG medium, artificial saliva (AS) medium, and SHI medium could obviously gain large oral biofilm in vitro. The nutrients contained in different culture media may be suitable for the growth of different oral bacteria; therefore, we optimized several novel media accordingly. Notably, results of crystal violet staining showed that the biofilm cultured in our modified artificial saliva (MAS) medium had the highest amount of biofilm biomass. 16S rRNA gene sequencing showed that the operational taxonomic units (OTUs) and Shannon index of biofilm cultured in MAS medium were also the highest among all the tested media. More importantly, the 16S rRNA gene sequencing analysis indicated that the biofilm cultured in MAS medium was closer to the original saliva species. Besides, biofilm cultured by MAS was denser and produced more exopolysaccharides. MAS supported stable biofilm formation on different substrata. In conclusion, this study demonstrated a novel MAS medium that could culture oral biofilm in vitro closer to the original oral microbiome, showing a good application prospect. KEY POINTS: • We compare the effects of different media in culturing oral biofilms • A novel modified artificial saliva (MAS) medium was obtained in our study • The MAS medium could culture biofilm that was closer to oral microbiome.


Assuntos
Bactérias , Biofilmes , Meios de Cultura , Microbiota , Boca , RNA Ribossômico 16S , Saliva , Biofilmes/crescimento & desenvolvimento , Meios de Cultura/química , Boca/microbiologia , Humanos , RNA Ribossômico 16S/genética , Saliva/microbiologia , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , Saliva Artificial
10.
BMC Neurosci ; 24(1): 63, 2023 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057703

RESUMO

BACKGROUND: Ischemic stroke is a serious disease leading to significant disability in humans worldwide. Increasing evidence suggests that some microRNAs (miRNAs) participate in the pathophysiology of ischemic stroke. A key role for MiR-212 has been found in neuronal function and synaptic plasticity. Ischemic stroke can be effectively treated with electroacupuncture (EA); however, there is a lack of understanding of the relevant mechanisms. In this study, we employed behavioral test and resting-state functional magnetic resonance imaging (rs-fMRI) to detect behavioral and brain function alterations in rats suffering from ischemic stroke. The efficacy of EA therapy and miR-212-5p's role in this process were also evaluated. METHODS AND RESULTS: Forty rats were randomly divided into the following groups: Sham, middle cerebral artery occlusion/reperfusion (MCAO/R), MCAO/R + EA, MCAO/R + EA + antagomir-negative control and MCAO/R + EA + antagomir-212-5p groups. Behavioral changes were assessed by Catwalk gait analysis prior to and after modeling. Rs-fMRI was performed at one week after EA treatment, amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were calculated to reveal neural activity. Furthermore, neuronal apoptosis in the ischemic penumbra was analyzed using a TUNEL assay. Treatment with EA significantly improved the performance of rats in the behavioral test. The motor and cognition-related brain regions showed decreased ALFF and ReHo following focal cerebral ischemia-reperfusion, and EA treatment could reactivate these brain regions. Moreover, EA treatment significantly decreased MCAO/R-induced cell death. However, the transfection of antagomir-212-5p attenuated the therapeutic effect of EA. CONCLUSIONS: In conclusion, the results suggested that EA improved the behavioral and imaging outcomes of ischemic stroke through miR-212-5p.


Assuntos
Isquemia Encefálica , Eletroacupuntura , AVC Isquêmico , MicroRNAs , Traumatismo por Reperfusão , Acidente Vascular Cerebral , Humanos , Ratos , Animais , Ratos Sprague-Dawley , Eletroacupuntura/métodos , Antagomirs , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/terapia , Isquemia Encefálica/metabolismo , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/terapia , MicroRNAs/metabolismo , Traumatismo por Reperfusão/terapia , Traumatismo por Reperfusão/metabolismo , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/metabolismo
11.
Cytokine ; 169: 156300, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37454542

RESUMO

BACKGROUND: Although osteoarthritis (OA) is one of the most prevalent joint disorders, effective biomarkers to diagnose OA are still unavailable. This study aimed to acquire some key synovial biomarkers (hub genes) and analyze their correlation with immune infiltration in OA. METHODS: Gene expression profiles and clinical characteristics of OA and healthy synovial samples were retrieved from the Gene Expression Omnibus (GEO) database. Hub genes for OA were mined based on a combination of weighted gene co-expression network analysis (WGCNA), the least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF) algorithms. A diagnostic nomogram model for OA prediction was developed based on the hub genes. Receiver operating characteristic curves (ROC) were performed to confirm the abnormal expression of hub genes in the experimemtal and validation datasets. qRT-PCR using patients' samples were conducted as well. In addition, the infiltration level of 28 immune cells in the expression profile and their relationship with hub genes were analyzed using single-sample GSEA (ssGSEA). RESULTS: 4 hub genes (ZBTB16, TNFSF11, SCRG1 and KDELR3) were obtained by WGCNA, lasso, SVM-RFE, RF algorithms as potential biomarkers for OA. The immune infiltration analyses revealed that hub genes were most correlated with regulatory T cell and natural killer cell. CONCLUSION: A machine learning model to diagnose OA based on ZBTB16, TNFSF11, SCRG1 and KDELR3 using synovial tissue was constructed, providing theoretical foundation and guideline for diagnostic and treatment targets in OA.


Assuntos
Osteoartrite , Humanos , Osteoartrite/diagnóstico , Osteoartrite/genética , Biologia Computacional , Bases de Dados Factuais , Perfilação da Expressão Gênica , Aprendizado de Máquina
12.
Appl Opt ; 62(3): 654-664, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36821269

RESUMO

A quadriwave lateral shearing interferometry (QWLSI) is proposed based on double birefringent crystals of a beam displacer (DBCs-BD). The DBCs-BD is formed by adopting two birefringent crystals of a polarization beam displacer (PBD), which can generate the lateral shearing interference waves of four beams of overlapped replicas in the DBCs-BD orthogonal directions. When the replica waves are overlapped incident to the analyzer, and the direction of the transmission axis is set as 45° or 135°, the QWLSI's polarization interferogram can be obtained. The high-precision phase can be obtained by simple spectrum denoising and performing the Fourier transform of the resulting interferogram. We deduce the principle of QWLSI in detail, and the wavefront distribution can be achieved by the phase calculation. The experiment shows that the DBCs-BD-QWLSI exhibits feasibility and high precision.

13.
Proc Natl Acad Sci U S A ; 117(38): 23499-23509, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32907946

RESUMO

Understanding the molecular basis of male sterility and developing practical male-sterility systems are essential for heterosis utilization and commercial hybrid seed production in crops. Here, we report molecular regulation by genic male-sterility gene maize male sterility 7 (ZmMs7) and its application for developing a dominant male-sterility system in multiple species. ZmMs7 is specifically expressed in maize anthers, encodes a plant homeodomain (PHD) finger protein that functions as a transcriptional activator, and plays a key role in tapetal development and pollen exine formation. ZmMs7 can interact with maize nuclear factor Y (NF-Y) subunits to form ZmMs7-NF-YA6-YB2-YC9/12/15 protein complexes that activate target genes by directly binding to CCAAT box in their promoter regions. Premature expression of ZmMs7 in maize by an anther-specific promoter p5126 results in dominant and complete male sterility but normal vegetative growth and female fertility. Early expression of ZmMs7 downstream genes induced by prematurely expressed ZmMs7 leads to abnormal tapetal development and pollen exine formation in p5126-ZmMs7 maize lines. The p5126-ZmMs7 transgenic rice and Arabidopsis plants display similar dominant male sterility. Meanwhile, the mCherry gene coupled with p5126-ZmMs7 facilitates the sorting of dominant sterility seeds based on fluorescent selection. In addition, both the ms7-6007 recessive male-sterility line and p5126-ZmMs7M dominant male-sterility line are highly stable under different genetic germplasms and thus applicable for hybrid maize breeding. Together, our work provides insight into the mechanisms of anther and pollen development and a promising technology for hybrid seed production in crops.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Regiões Promotoras Genéticas/genética , Zea mays/genética , Arabidopsis/genética , Produtos Agrícolas , Oryza/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Pólen/genética , Zea mays/crescimento & desenvolvimento
14.
J Environ Manage ; 348: 119184, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37832291

RESUMO

Grazing and climate change both contribute to diversity loss and productivity fluctuations. Sensitive climate conditions and long-term grazing activities have a profound influence on community change, particularly in high-altitude mountain grassland ecosystems. However, knowledge about the role of long-term continuous grazing management on diversity, productivity and the regulation mechanisms in fragile grassland ecosystems is still rudimentary. We conducted a long-term grazing experiment on an alpine typical steppe in the Qilian Mountains to assess effects of grazing intensity on soil, diversity, productivity and the regulation mechanisms. Plants and soil were sampled along grazing gradients at different distances from the pasture entrance (0, 0.3, 0.6, 0.9, 1.2 and 1.5 km) under the non-growing (WP) and the growing season grazing pasture (SAP). The results revealed that community diversity and biomass did not change significantly on a time scale, while the concentration of soil organic carbon and total phosphorus increased significantly. Heavy grazing (0-0.3 km) decreased community diversity and biomass. Grazing increased soil chemical properties in heavy grazed areas of WP, while the opposite was recorded in SAP. Soil chemical properties explained the largest variances in community diversity and community biomass. The prediction model indicates that grazing in WP mainly affects community diversity through soil chemical properties, and promotes a positive correlation between community diversity and community biomass; in SAP, the direct effect of grazing gradients on community diversity and biomass is the main pathway, but not eliminating the single positive relationship between diversity and biomass, which means that diversity can still be used as a potential resource to promote productivity improvement. Therefore, we should focus on the regulation of soil chemical properties in WP, such as the health and quality of soil, strengthening its ability to store water, sequester carbon and increase nutrients; focus on the management of livestock in SAP, including providing fertilizer and sowing to increase diversity and production in heavily grazed regions and reducing grazing pressure through regional rotational grazing. Ultimately, we call for strengthening the stability and sustainability of ecosystems through targeted and active human intervention in ecologically sensitive areas to cope with future grazing pressures and climate disturbances.


Assuntos
Ecossistema , Pradaria , Humanos , Solo/química , Carbono , Biomassa
15.
Sheng Li Xue Bao ; 75(3): 317-327, 2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37340641

RESUMO

The present study aimed to investigate the protective effect of S-propargyl-cysteine (SPRC) on atherosclerosis progression in mice. A mouse model of vulnerable atherosclerotic plaque was created in ApoE-/- mice by carotid artery tandem stenosis (TS) combined with a Western diet. Macrophotography, lipid profiles, and inflammatory markers were measured to evaluate the antiatherosclerotic effects of SPRC compared to atorvastatin as a control. Histopathological analysis was performed to assess the plaque stability. To explore the protective mechanism of SPRC, human umbilical vein endothelial cells (HUVECs) were cultured in vitro and challenged with oxidized low-density lipoprotein (ox-LDL). Cell viability was determined with a Cell Counting Kit-8 (CCK-8). Endothelial nitric oxide synthase (eNOS) phosphorylation and mRNA expression were detected by Western blot and RT-qPCR respectively. The results showed that the lesion area quantified by en face photographs of the aortic arch and carotid artery was significantly less, plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were reduced, plaque collagen content was increased and matrix metalloproteinase-9 (MMP-9) was decreased in 80 mg/kg per day SPRC-treated mice compared with model mice. These findings support the role of SPRC in plaque stabilization. In vitro studies revealed that 100 µmol/L SPRC increased the cell viability and the phosphorylation level of eNOS after ox-LDL challenge. These results suggest that SPRC delays the progression of atherosclerosis and enhances plaque stability. The protective effect may be at least partially related to the increased phosphorylation of eNOS in endothelial cells.


Assuntos
Aterosclerose , Placa Aterosclerótica , Animais , Humanos , Camundongos , Colesterol/metabolismo , Cisteína/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Lipoproteínas LDL/farmacologia , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/metabolismo , Fosforilação , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia
16.
Neuroimage ; 261: 119514, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35901916

RESUMO

We leveraged a novel index of diffusion MRI to investigate the relationships among cortical free water, macro-organizations and gene expression in healthy adults. Few research has been conducted to investigate the role of free water in the healthy adults due to it can easily be affected also by aging diseases. High quality data of 350 subjects from Human Connectome Project were used in our study. Cortical free water was estimated by using a bi-tensor model. The free water was high in the limbic, insular and somatosensory cortex, while being lower in motor and association cortex. The negative correlation between the free water and cortical thickness has been consistently identified in almost all the cortical regions. Negative correlation between the cortical free water and structural covariance (rho=-0.38, pspin=0.005) revealed the free water was sensitive to cortical heterogeneity. Using human gene expression dataset, we found the gene expression pattern of the relationship between the free water and cortical thickness spatially coupled with primary gradient of structural covariance network (rho=0.40, pspin=0.004). Our findings indicated the free water was sensitive to the cortical cellular status. The relationship between free water and macroscale organization also reflected hierarchal structures of cerebral cortex.


Assuntos
Conectoma , Água , Adolescente , Adulto , Córtex Cerebral/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética
17.
Small ; 18(47): e2203431, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36180405

RESUMO

Mesenchymal stem cell (MSC) therapy via intravenous transplantation exhibits great potential for brain tissue regeneration, but still faces thorny clinical translation challenges as the unknown dynamic fate leads to the contentious therapeutic mechanism and the poor MSC viability in harsh lesions limits therapeutic efficiency. Here, a vitality-enhanced dual-modal tracking system is designed to improve engraftment efficiency and is utilized to noninvasively explore the fate of intravenous transplanted human umbilical cord-derived MSCs during long-term treatment of ischemic stroke. Such a system is obtained by bioorthogonally conjugating magnetic resonance imaging (MRI) contrast and near-infrared fluorescence (NIRF) imaging nanoparticles to metabolic glycoengineered MSCs with a lipoic acid-containing extracellular antioxidative protective layer. The dynamic fates of MSCs in multi-dimensional space-time evolution are digitally detailed for up to 28 days using MRI and NIRF imaging equipment, and the protective layer greatly shields MSCs from reactive oxygen spices (ROS) degradation, enhances MSC survival, and engraftment efficiency. Additionally, it is observed that the bioengineered MSCs exhibit dynamic intelligent responses corresponding to microenvironment remodeling and exert enhanced therapeutic effects. This dual-modal tracking system enables long-term tracking of MSCs while improving their viability at the lesion sites, which may serve as a valuable tool for expediting the clinical translation of MSC therapy.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Acidente Vascular Cerebral , Humanos , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/metabolismo , Cordão Umbilical , Imageamento por Ressonância Magnética/métodos , Meios de Contraste/metabolismo , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia
18.
Opt Express ; 30(19): 34297-34313, 2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36242445

RESUMO

In a simultaneous phase-shifted lateral shearing interferometry, a division of focal plane polarization camera is generally used as the phase-shifting device. However, acquiring simultaneous phase-shift interferograms in a single frame suffers from a lack of spatial resolution, significantly affecting the phase reconstruction accuracy. A polarization redundant sub-region interpolation (PRSI) method is proposed to solve this problem. This interpolation method distinguishes smooth regions from stripe fringe regions by calculating the polarization redundancy error of the synchronous phase shift interferogram. After sub-regional processing, resolution reconstruction is performed in the smoothed area using a fast convolutional bilinear interpolation method. In the streak detail region, the resolution reconstruction is performed based on the strength of the correlation between the orthogonal and non-orthogonal polarization channels crossing the streak region. The PRSI method can quickly reconstruct the lost pixels and accurately recover the stripe detail information. Experiment results show that the proposed interpolation method outperforms the existing dominant methods in terms of visual reconstruction effect and quantitative index of phase reconstruction.

19.
Nanomedicine ; 33: 102348, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33321215

RESUMO

Atherosclerosis can lead to most cardiovascular diseases. Although some biomimetic nanomaterials coated by macrophage membranes have been reported in previous studies of atherosclerosis, to our knowledge, no studies regarding the detection of early lesions of atherosclerosis (foam cells) using such a strategy have yet been reported. In the present study, Fe3O4 biomimetic nanoparticles coated with a macrophage membrane (Fe3O4@M) were prepared to investigate the imaging effect on the early lesions of atherosclerosis (foam cells). The results showed that the Fe3O4@M particles are spheres with average diameters of approximately 300 nm. T1 and T2 relaxation values showed that the ratio of r2 to r1 was 26.09. The protein content accounted for approximately 27% of the total weight in Fe3O4@M, and Fe3O4@M nanoparticles exhibited high biosafety. Further testing showed that Fe3O4@M effectively targets early atherosclerotic lesions by the specific recognition of integrin α4ß1 to VCAM-1. Taken together, Fe3O4@M is a promising contrast agent for the diagnosis of early stage atherosclerosis.


Assuntos
Materiais Biomiméticos/química , Meios de Contraste/química , Nanopartículas de Magnetita/química , Animais , Aterosclerose , Permeabilidade da Membrana Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Macrófagos/química , Macrófagos/metabolismo , Imageamento por Ressonância Magnética , Camundongos , Células RAW 264.7 , Propriedades de Superfície , Molécula 1 de Adesão de Célula Vascular/metabolismo
20.
J Cell Mol Med ; 24(20): 11703-11717, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32864857

RESUMO

Pituitary stalk interruption syndrome (PSIS) is a type of congenital malformation of the anterior pituitary, which leads to isolated growth hormone deficiency or multiple hypothalamic-pituitary deficiencies. Many genetic factors have been explored, but they only account for a minority of the genetic aetiology. To identify novel PSIS pathogenic genes, we conducted whole-exome sequencing with 59 sporadic PSIS patients, followed by filtering gene panels involved in pituitary development, holoprosencephaly and midline abnormality. A total of 81 heterozygous variants, distributed among 59 genes, were identified in 50 patients, with 31 patients carrying polygenic variants. Fourteen of the 59 pathogenic genes clustered to the Hedgehog pathway. Of them, PTCH1 and PTCH2, inhibitors of Hedgehog signalling, showed the most frequent heterozygous mutations (22%, seven missense and one frameshift mutations were identified in 13 patients). Moreover, five novel heterozygous null variants in genes including PTCH2 (p.S391fs, combined with p.L104P), Hedgehog acyltransferase (p.R280X, de novo), MAPK3 (p.H50fs), EGR4 (p.G22fs, combined with LHX4 p.S263N) and SPG11 (p.Q1624X), which lead to truncated proteins, were identified. In conclusion, genetic mutations in the Hedgehog signalling pathway might underlie the complex polygenic background of PSIS, and the findings of our study could extend the understanding of PSIS pathogenic genes.


Assuntos
Sequenciamento do Exoma , Estudos de Associação Genética , Predisposição Genética para Doença , Doenças da Hipófise/genética , Adolescente , Adulto , Sequência de Aminoácidos , Sequência de Bases , Família , Feminino , Mutação da Fase de Leitura/genética , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Doenças da Hipófise/diagnóstico , Adulto Jovem
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