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1.
Methods Mol Biol ; 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34505270

RESUMO

Bioreactors can offer an advanced platform to provide conditions that mimic the native microenvironment, which can also provide stretching environment for mechanobiology research. Tendon-derived stem cells (TDSCs) are a type of mechanosensitive and multipotent cells, which behave differently in diverse mechanical stretching environments. We have proved the in vitro three-dimensional (3D) mechanical stimulation could closely mimic the stretching environment in vivo. Thus, here we describe applying a customized bioreactor to provide 3D force for mechanical stimulation on TDSC in vitro.

2.
Food Res Int ; 147: 110546, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399523

RESUMO

A sulfated polysaccharide (PHP1) produced by the marine red alga Porphyra haitanensis was structurally characterized, and its effect on rat fecal microbiota fermentations and short chain fatty acids production were investigated. PHP1 was mainly composed of galactose and the main linkage types were identified as â†’ 3)G4Sß(1 â†’ 3)G(1 â†’ 6)G4Sα(1 â†’ 4)LA(1 â†’ 6)G4Sα(1→. The surface morphology of dried PHP1 films appears to be related to its chemical structure. PHP1 promoted the growth of both propionic acid-producing bacteria and propionic acid production, as well as influencing the composition and abundance of beneficial microbiota species in rats, which may be related to its high level of sulfation. The molecular weight of PHP1 decreased significantly after fermentation, which may result from hydrolysis of the galactan (with α- and ß-linkages between galactose residues) by α- or ß-galactosidase secreted by the microbiota. These results provided new insights into the structure-activity relationships between P. haitanensis polysaccharide and its regulation of microbiota in vivo.


Assuntos
Microbioma Gastrointestinal , Porphyra , Rodófitas , Animais , Fermentação , Polissacarídeos , Ratos
3.
Theranostics ; 11(16): 7640-7657, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335955

RESUMO

Background: Since primary prostate cancer (PCa) can advance to the life-threatening metastatic PCa, exploring the molecular mechanisms underlying PCa metastasis is crucial for developing the novel targeted preventive strategies for decreasing the mortality of PCa. RNA N6-methyladenosine (m6A) is an emerging regulatory mechanism for gene expression and its specific roles in PCa progression remains elusive. Methods: Western blotting, quantitative real-time PCR and immunohistochemical analyses were used to detect target gene expression in PCa cells in vitro and prostate tissues from patients. RNA immunoprecipitation was conducted to analyze the specific binding of mRNA to the target protein. Migration and invasion assays were used to assess the migratory capacities of cancer cells. The correlation between target gene expression and survival rate of PCa patients was analyzed based the TCGA database. Results: We found that total RNA N6-methyladenosine (m6A) modification levels were markedly upregulated in human PCa tissues due to increased expression of methyltransferase like 3 (METTL3). Further studies revealed that the migratory and invasive capacities of PCa cells were markedly suppressed upon METTL3 knockdown. Mechanistically, METTL3 mediates m6A modification of USP4 mRNA at A2696, and m6A reader protein YTHDF2 binds to and induces degradation of USP4 mRNA by recruiting RNA-binding protein HNRNPD to the mRNA. Decrease of USP4 fails to remove the ubiquitin group from ELAVL1 protein, resulting in a reduction of ELAVL1 protein. Lastly, downregulation of ELAVL1 in turn increases ARHGDIA expression, promoting migration and invasion of PCa cells. Conclusions: Our findings highlight the role of METTL3 in modulating invasion and metastasis of PCa cells, providing insight into promising therapeutic strategies for hindering PCa progressing to deadly metastases.


Assuntos
Metiltransferases/genética , Neoplasias da Próstata/metabolismo , Adenosina/análogos & derivados , Adenosina/genética , Adenosina/metabolismo , Movimento Celular/genética , Proliferação de Células/genética , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/genética , Inativação Gênica/fisiologia , Humanos , Masculino , Metiltransferases/metabolismo , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/metabolismo , Proteases Específicas de Ubiquitina/genética
4.
Artigo em Inglês | MEDLINE | ID: mdl-34370665

RESUMO

Real-world video processing algorithms are often faced with the great challenges of processing the compressed videos instead of pristine videos. Despite the tremendous successes achieved in deep-learning based video super-resolution (SR), much less work has been dedicated to the SR of compressed videos. Herein, we propose a novel approach for compressed domain deep video SR by jointly leveraging the coding priors and deep priors. By exploiting the diverse and ready-made spatial and temporal coding priors (e.g., partition maps and motion vectors) extracted directly from the video bitstream in an effortless way, the video SR in the compressed domain allows us to accurately reconstruct the high resolution video with high flexibility and substantially economized computational complexity. More specifically, to incorporate the spatial coding prior, the Guided Spatial Feature Transform (GSFT) layer is proposed to modulate features of the prior with the guidance of the video information, making the prior features more fine-grained and content-adaptive. To incorporate the temporal coding prior, a guided soft alignment scheme is designed to generate local attention off-sets to compensate for decoded motion vectors. Our soft alignment scheme combines the merits of explicit and implicit motion modeling methods, rendering the alignment of features more effective for SR in terms of the computational complexity and robustness to inaccurate motion fields. Furthermore, to fully make use of the deep priors, the multi-scale fused features are generated from a scale-wise convolution reconstruction network for final SR video reconstruction. To promote the compressed domain video SR research, we build an extensive Compressed Videos with Coding Prior (CVCP) dataset, including compressed videos of diverse content and various coding priors extracted from the bitstream. Extensive experimental results show the effectiveness of coding priors in compressed domain video SR.

5.
Org Lett ; 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34355911

RESUMO

The reaction of o-benzofulvene with TfOH leads to intramolecular cyclization through novel C-C and C-N bond formation, resulting in the formation of 5H,10'H-spiro[benzo[k]phenanthridine-5,6'-dibenzopentalene]. This protocol provides a new molecular framework with reasonable to excellent yields and tolerates various electron-withdrawing/donating substituents. This method yields diastereoselectivity of up to >20:1. Furthermore, it is free of bases, oxidants, and metals and proceeds under mild reaction conditions, which are favorable for synthetic organic chemistry.

6.
Forensic Sci Int ; 326: 110917, 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34314986

RESUMO

The identification of new psychoactive substances (NPSs) is essential against drug abuse, especially for "new" drugs that are not regulated by international drug conventions. A suspicious powder seized by the officers of Taipei Customs Administration of Taiwan was sent to this laboratory for analysis by using gas chromatography-mass spectrometry (GCMS), liquid chromatography-high resolution mass spectrometry (LCHRMS), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR) with distortionless enhancement by polarization transfer (DEPT) at proton pulses of 45°, 90°, and 135°, two-dimensional correlation NMR measurements (2D_COSY), and heteronuclear single-quantum correlation NMR measurements (2D_HSQC). However, the structure of this "unknown" sample was difficult to identify. Alternatively, single-crystal X-ray crystallography was applied for structural determination after the crystallization of the compound in methanol. The structure was thus identified as N-(2,6-dimethylphenyl)-1-phenethylpiperidine-2-carboxamide (NDMPPPC), an analog of bupivacaine with similar pharmacological effects to those of cocaine, ketamine and morphine. The identification of NDMPPPC is in accordance with all mass fragments and NMR signal data, demonstrating that single-crystal X-ray diffraction can be used for structural determination, especially for complicated structures of "new" drugs or "unknown" samples. The seizure of NDMPPPC from smuggling indicates a great potential to become part of the next generation of NPSs.

7.
Front Immunol ; 12: 679839, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276668

RESUMO

Background: It is highly desirable to develop new strategies based on secretomics to more accurately selection of embryos with the highest developmental potential for transfer. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been reported to promote embryo development and pregnancy establishment. However, the predictive value of GM-CSF in single blastocyst selection remains unclear. This study is to determine the concentration of GM-CSF in human single-blastocyst conditioned medium (SBCM) and to evaluate its association with embryo quality and pregnancy outcome. Methods: The patients with ≤38 years of age receiving the first cycle of assisted reproductive therapy were included in this study. The patients who had <4 top-quality embryos formed by the fertilized two pronuclear zygotes on day 3 were excluded. A total of 126 SBCM samples (SBCMs) were included, of which blastocysts from 77 SBCMs were later transferred in subsequent frozen-thawed embryo transfer. The concentrations of GM-CSF were detected by single-molecule array (SIMOA) and analyzed for their possible association with embryo quality and pregnancy outcomes. The top-quality embryo (TQ), positive HCG (HP), clinical pregnancy (CP), and ongoing pregnancy (OP) rates were determined and compared between groups divided based on GM-CSF concentrations. Results: The detection rate of GM-CSF was found to be 50% in all SBCMs. There were significant differences in TQ rate, HP rate, CP rate and OP rate among high concentration group, medium concentration group and low concentration group. Both GM-CSF alone or GM-CSF combined with the morphological score (MS) had a greater AUC of ROC curve than that of MS alone to predict the pregnancy outcome, and GM-CSF combined with MS had the highest AUC. Conclusions: The concentration of GM-CSF in SBCM was detected at fg/ml levels, which was associated with embryo quality and pregnancy outcome. Collectively, GM-CSF may be used as a biomarker for prediction of pregnancy outcome and selection of embryos with high developmental potential for transfer in assisted reproductive technology (ART).

8.
Chem Commun (Camb) ; 57(53): 6542-6545, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34109342

RESUMO

A novel titanium(iii) phosphite with intriguing polymorphism and solid-state proton-coupled electron transfer (PCET) oxidation is presented. The polymorphs show structure-dependent PCET reactivity, interpretable by proton distribution in channels. Combined with subsequent photoreduction, the redox cycle initiated with TiIII can produce H2 and transform organics.

9.
J Sci Food Agric ; 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33997981

RESUMO

BACKGROUND: The separation and purification of Porphyra haitanensis polysaccharide (PHP), and the determination of changes in molecular weight (Mw) and antioxidant capacity after in vitro digestion, were undertaken. RESULTS: Analysis of two polysaccharide fractions (PHP0.5-1-UF and PHP1.0-1-UF) by various techniques showed that they were very pure sulfated polysaccharides without pigment or protein. PHP0.5-1-UF was filamentous or 'tape-like' sheets, whereas PHP1.0-1-UF had some filaments and large numbers of rounded aggregates. The Mw of PHP, PHP0.5-1-UF and PHP1.0-1-UF was 2.06 × 106 (±2.02%), 6.68 × 106 (±3.17%), and 1.14 × 106 (±3.44%) (g mol-1 ), respectively. After in vitro digestion, the Mw of PHP, PHP0.5-1-UF, and PHP1.0-1-UF decreased. Their antioxidant capacities were markedly higher than before digestion, especially PHP0.5-1-UF and its digestion products, which might be related to the reductions in Mw. CONCLUSION: These findings provide a greater understanding of the separation and purification of sulfated polysaccharides and the influence of digestion on biological activity. They also contribute to the practical application of sulfated polysaccharides in functional foods. © 2021 Society of Chemical Industry.

10.
Medicine (Baltimore) ; 100(20): e25994, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34011092

RESUMO

ABSTRACT: In precision oncology, immune check point blockade therapy has quickly emerged as novel strategy by its efficacy, where programmed death ligand 1 (PD-L1) expression is used as a clinically validated predictive biomarker of response for the therapy. Automating pathological image analysis and accelerating pathology evaluation is becoming an unmet need. Artificial Intelligence and deep learning tools in digital pathology have been studied in order to evaluate PD-L1 expression in PD-L1 immunohistochemistry image. We proposed a Dual-scale Categorization (DSC)-based deep learning method that employed 2 VGG16 neural networks, 1 network for 1 scale, to critically evaluate PD-L1 expression. The DSC-based deep learning method was tested in a cohort of 110 patients diagnosed as non-small cell lung cancer. This method showed a concordance of 88% with pathologist, which was higher than concordance of 83% of 1-scale categorization-based method. Our results show that the DSCbased method can empower the deep learning application in digital pathology and facilitate computer-aided diagnosis.


Assuntos
Antígeno B7-H1/análise , Biomarcadores Tumorais/análise , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Diagnóstico por Computador/métodos , Neoplasias Pulmonares/diagnóstico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Aprendizado Profundo , Regulação Neoplásica da Expressão Gênica , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Imuno-Histoquímica , Pulmão/imunologia , Pulmão/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Seleção de Pacientes , Medicina de Precisão/métodos
11.
Sci Adv ; 7(17)2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33893103

RESUMO

The delivery of therapeutics through the circulatory system is one of the least arduous and less invasive interventions; however, this approach is hampered by low vascular density or permeability. In this study, by exploiting the ability of monocytes to actively penetrate into diseased sites, we designed aptamer-based lipid nanovectors that actively bind onto the surface of monocytes and are released upon reaching the diseased sites. Our method was thoroughly assessed through treating two of the top causes of death in the world, cardiac ischemia-reperfusion injury and pancreatic ductal adenocarcinoma with or without liver metastasis, and showed a significant increase in survival and healing with no toxicity to the liver and kidneys in either case, indicating the success and ubiquity of our platform. We believe that this system provides a new therapeutic method, which can potentially be adapted to treat a myriad of diseases that involve monocyte recruitment in their pathophysiology.

12.
Adv Biol (Weinh) ; 5(1): e2000200, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33724730

RESUMO

The effect of the intracellular pH of macrophages after taking up biodegradable polymer nanoparticles (NPs) on immunomodulating functions has not been explored so far. Previous studies have demonstrated that biodegradable polyurethane (PU) NPs exhibit immunosuppressive activity. Yet, the intracellular mechanism is not clearly understood. In this study, a uniquely designed pH nanosensor is employed for tracking the intracellular pH value of macrophages to reveal the intracellular journey of PU NPs and to clarify the intracellular pH effect on the corresponding inflammatory response. First, fluorescent mesoporous silica nanoparticles (FRMSNs) is used to detect the pH change in macrophages after endo/phagocytosis of PU NPs. Second, PU is coated on the external surface of FRMSNs to examine the intracellular trafficking process of PU in the macrophages. The results show that the majority of PU-coated FRMSNs remain to stay at the cytosol-early endosome/phagosome regions. The intracellular pH value and other supporting results show that the immune response of PU NPs may be correlated to their internalization journey. The retardation in the degradation process of the PU NPs may intervene with the lysosome activity and repress the immunostimulatory effect, which contributes to the low immune response of PU NPs.

13.
J Mater Chem B ; 9(10): 2532-2546, 2021 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-33660730

RESUMO

Finding the right balance in mechanical properties and degradation rate of biodegradable materials for biomedical applications is challenging, not only at the time of implantation but also during biodegradation. For instance, high elongation at break and toughness with a mid-term degradation rate are required for tendon scaffold or suture application, which cannot be found in each alpha polyester individually. Here, we hypothesise that blending semi-crystalline poly(p-dioxanone) (PDO) and poly(lactide-co-caprolactone) (LCL) in a specific composition will enhance the toughness while also enabling tailored degradation times. Hence, blends of PDO and LCL (PDO/LCL) were prepared in varying concentrations and formed into films by solvent casting. We thoroughly characterised the chemical, thermal, morphological, and mechanical properties of the new blends before and during hydrolytic degradation. Cellular performance was determined by seeding mouse fibroblasts onto the samples and culturing for 72 hours, before using proliferation assays and confocal imaging. We found that an increase in LCL content causes a decrease in hydrolytic degradation rate, as indicated by induced crystallinity, surface and bulk erosions, and tensile properties. Interestingly, the noncytotoxic blend containing 30% PDO and 70% LCL (PDO3LCL7) resulted in small PDO droplets uniformly dispersed within the LCL matrix and demonstrated a tailored degradation rate and toughening behaviour with a notable strain-hardening effect reaching 320% elongation at break; over 3 times the elongation of neat LCL. In summary, this work highlights the potential of PDO3LCL7 as a biomaterial for biomedical applications like tendon tissue engineering or high-performance absorbable sutures.


Assuntos
Materiais Biocompatíveis/química , Dioxanos/química , Poliésteres/química , Polímeros/química , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/uso terapêutico , Linhagem Celular , Proliferação de Células , Fibroblastos/citologia , Fibroblastos/metabolismo , Congelamento , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Cinética , Ligamentos , Camundongos , Temperatura , Tendões , Resistência à Tração , Fatores de Tempo
14.
Plant Mol Biol ; 105(6): 585-599, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33651261

RESUMO

KEY MESSAGE: Total of 14 SNPs associated with overwintering-related traits and 75 selective regions were detected. Important candidate genes were identified and a possible network of cold-stress responses in woody plants was proposed. Local adaptation to low temperature is essential for woody plants to against changeable climate and safely survive the winter. To uncover the specific molecular mechanism of low temperature adaptation in woody plants, we sequenced 134 core individuals selected from 494 paper mulberry (Broussonetia papyrifera), which naturally distributed in different climate zones and latitudes. The population structure analysis, PCA analysis and neighbor-joining tree analysis indicated that the individuals were classified into three clusters, which showed forceful geographic distribution patterns because of the adaptation to local climate. Using two overwintering phenotypic data collected at high latitudes of 40°N and one bioclimatic variable, genome-phenotype and genome-environment associations, and genome-wide scans were performed. We detected 75 selective regions which possibly undergone temperature selection and identified 14 trait-associated SNPs that corresponded to 16 candidate genes (including LRR-RLK, PP2A, BCS1, etc.). Meanwhile, low temperature adaptation was also supported by other three trait-associated SNPs which exhibiting significant differences in overwintering traits between alleles within three geographic groups. To sum up, a possible network of cold signal perception and responses in woody plants were proposed, including important genes that have been confirmed in previous studies while others could be key potential candidates of woody plants. Overall, our results highlighted the specific and complex molecular mechanism of low temperature adaptation and overwintering of woody plants.


Assuntos
Adaptação Fisiológica/genética , Temperatura Baixa , Fenômenos Fisiológicos Vegetais , Plantas/genética , Alelos , Sequência de Bases , Clima , Estudo de Associação Genômica Ampla , Morus/genética , Morus/fisiologia , Fenótipo , Polimorfismo de Nucleotídeo Único , Temperatura
15.
Stem Cell Res Ther ; 12(1): 38, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413592

RESUMO

BACKGROUND: Botulinum toxin (Botox) injection is in widespread clinical use for the treatment of muscle spasms and tendinopathy but the mechanism of action is poorly understood. HYPOTHESIS: We hypothesised that the reduction of patellar-tendon mechanical-loading following intra-muscular injection of Botox results in tendon atrophy that is at least in part mediated by the induction of senescence of tendon-derived stem cells (TDSCs). STUDY DESIGN: Controlled laboratory study METHODS: A total of 36 mice were randomly divided into 2 groups (18 Botox-injected and 18 vehicle-only control). Mice were injected into the right vastus lateralis of quadriceps muscles either with Botox (to induce mechanical stress deprivation of the patellar tendon) or with normal saline as a control. At 2 weeks post-injection, animals were euthanized prior to tissues being harvested for either evaluation of tendon morphology or in vitro studies. TDSCs were isolated by cell-sorting prior to determination of viability, differentiation capacity or the presence of senescence markers, as well as assessing their response to mechanical loading in a bioreactor. Finally, to examine the mechanism of tendon atrophy in vitro, the PTEN/AKT-mediated cell senescence pathway was evaluated in TDSCs from both groups. RESULTS: Two weeks after Botox injection, patellar tendons displayed several atrophic features including tissue volume reduction, collagen fibre misalignment and increased degradation. A colony formation assay revealed a significantly reduced number of colony forming units of TDSCs in the Botox-injected group compared to controls. Multipotent differentiation capacities of TDSCs were also diminished after Botox injection. To examine if mechanically deprived TDSC are capable of forming tendon tissue, we used an isolated bioreactor system to culture tendon constructs using TDSC. These results showed that TDSCs from the Botox-treated group failed to restore tenogenic differentiation after appropriate mechanical loading. Examination of the signalling pathway revealed that injection of Botox into quadriceps muscles causes PTEN/AKT-mediated cell senescence of TDSCs. CONCLUSION: Intramuscular injection of Botox interferes with tendon homeostasis by inducing tendon atrophy and senescence of TDSCs. Botox injection may have long-term adverse consequences for the treatment of tendinopathy. CLINICAL RELEVANCE: Intramuscular Botox injection for tendinopathy or tendon injury could result in adverse effects in human tendons and evaluation of its long-term efficacy is warranted.


Assuntos
Toxinas Botulínicas , Animais , Atrofia/patologia , Toxinas Botulínicas/toxicidade , Diferenciação Celular , Injeções Intramusculares , Camundongos , Células-Tronco/patologia , Tendões
16.
J Clin Invest ; 131(1)2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33055419

RESUMO

Psoriasis is a chronic inflammatory skin disease characterized by inflammatory cell infiltration, as well as hyperproliferation of keratinocytes in skin lesions, and is considered a metabolic syndrome. We found that the expression of galectin-7 is reduced in skin lesions of patients with psoriasis. IL-17A and TNF-α, 2 cytokines intimately involved in the development of psoriatic lesions, suppressed galectin-7 expression in human primary keratinocytes (HEKn cells) and the immortalized human keratinocyte cell line HaCaT. A galectin-7 knockdown in these cells elevated the production of IL-6 and IL-8 and enhanced ERK signaling when the cells were stimulated with IL-17A. Galectin-7 attenuated IL-17A-induced production of inflammatory mediators by keratinocytes via the microRNA-146a/ERK pathway. Moreover, galectin-7-deficient mice showed enhanced epidermal hyperplasia and skin inflammation in response to intradermal IL-23 injection. We identified fluvastatin as an inducer of galectin-7 expression by connectivity map analysis, confirmed this effect in keratinocytes, and demonstrated that fluvastatin attenuated IL-6 and IL-8 production induced by IL-17A. Thus, we validate a role of galectin-7 in the pathogenesis of psoriasis, in both epidermal hyperplasia and keratinocyte-mediated inflammatory responses, and formulate a rationale for the use of statins in the treatment of psoriasis.

17.
Curr Opin Genet Dev ; 67: 77-83, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33383256

RESUMO

With a spatial resolution breaking the diffraction limit of light, superresolution imaging allows the visualization of detailed structures of organelles such as mitochondria, cytoskeleton, nucleus, and so on. With multi-dimensional imaging (x, y, z, t, λ), namely, multi-color 3D live imaging enables us fully understand the function of the cell. It is necessary to analyze structural changes or molecular interactions across a large volume in 3D with different labelled targets. To achieve this goal, scientists recently have expanded the original 2D superresolution microscopic tools into 3D imaging techniques. In this review, we will discuss recent development in superresolution microscopy for live imaging with minimal phototoxicity. We will focus our discussion on the cell nucleus where the genetic materials are stored and processed. Machine learning algorism will be introduced to improve the axial resolution of superresolution imaging.

18.
Biotechnol Biofuels ; 13: 170, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072185

RESUMO

Background: Newly formed polyploids may experience short-term adaptative changes in their genome that may enhance the resistance of plants to stress. Considering the increasingly serious effects of drought on biofuel plants, whole genome duplication (WGD) may be an efficient way to proceed with drought resistant breeding. However, the molecular mechanism of drought response before/after WGD remains largely unclear. Result: We found that autoploid switchgrass (Panicum virgatum L.) 8X Alamo had higher drought tolerance than its parent amphidiploid 4X Alamo using physiological tests. RNA and microRNA sequencing at different time points during drought were then conducted on 8X Alamo and 4X Alamo switchgrass. The specific differentially expressed transcripts (DETs) that related to drought stress (DS) in 8X Alamo were enriched in ribonucleoside and ribonucleotide binding, while the drought-related DETs in 4X Alamo were enriched in structural molecule activity. Ploidy-related DETs were primarily associated with signal transduction mechanisms. Weighted gene co-expression network analysis (WGCNA) detected three significant DS-related modules, and their DETs were primarily enriched in biosynthesis process and photosynthesis. A total of 26 differentially expressed microRNAs (DEmiRs) were detected, and among them, sbi-microRNA 399b was only expressed in 8X Alamo. The targets of microRNAs that were responded to polyploidization and drought stress all contained cytochrome P450 and superoxide dismutase genes. Conclusions: This study explored the drought response of 8X and 4X Alamo switchgrass on both physiological and transcriptional levels, and provided experimental and sequencing data basis for a short-term adaptability study and drought-resistant biofuel plant breeding.

19.
J Vis Exp ; (162)2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32804168

RESUMO

Tendinopathy is a common chronic tendon disease relating to inflammation and degeneration in an orthopaedic area. With high morbidity, limited self-repairing capacity and, most importantly, no definitive treatments, tendinopathy still influences patients' life quality negatively. Tendon-derived stem cells (TDSCs), as primary precursor cells of tendon cells, play an essential role in both the development of tendinopathy, and functional and structural restoration after tendinopathy. Thus, a method that can in vitro mimic the in vivo differentiation of TDSCs into tendon cells would be useful. Here, the present protocol describes a method based on a three-dimensional (3D) uniaxial stretching system to stimulate the TDSCs to differentiate into tendon-like tissues. There are seven stages of the present protocol: isolation of mice TDSCs, culture and expansion of mice TDSCs, preparation of stimulation culture medium for cell sheet formation, cell sheet formation by culturing in stimulation medium, preparation of 3D tendon stem cell construct, assembly of the uniaxial-stretching mechanical stimulation complex, and evaluation of the mechanical stimulated in vitro tendon-like tissue. The effectiveness was demonstrated by histology. The entire procedure takes less than 3 weeks. To promote extracellular matrix deposition, 4.4 mg/mL ascorbic acid was used in the stimulation culture medium. A separated chamber with a linear motor provides accurate mechanical loading and is portable and easily adjusted, which is applied for the bioreactor. The loading regime in the present protocol was 6% strain, 0.25 Hz, 8 h, followed by 16 h rest for 6 days. This protocol could mimic cell differentiation in the tendon, which is helpful for the investigation of the pathological process of tendinopathy. Moreover, the tendon-like tissue is potentially used to promote tendon healing in tendon injury as an engineered autologous graft. To sum up, the present protocol is simple, economic, reproducible and valid.


Assuntos
Reatores Biológicos , Diferenciação Celular , Células-Tronco/citologia , Tendões/citologia , Animais , Biomarcadores/metabolismo , Forma Celular , Meios de Cultura/farmacologia , Matriz Extracelular/metabolismo , Masculino , Camundongos Endogâmicos C57BL
20.
BMC Pregnancy Childbirth ; 20(1): 460, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32787803

RESUMO

BACKGROUND: Early rescue intracytoplasmic sperm injection (ICSI) has been used in clinic as appropriate currently. While the outcomes of children born after this method were not well assessed. The purpose of this study was to evaluate the effect of early rescue ICSI on women with primary infertility. METHODS: Fresh embryo transfer cycles after rescue (n = 214) and conventional (n = 546) ICSI were retrospectively evaluated from women with primary infertility who underwent their first assisted reproductive technology cycles at our center in 2012-2017. The conventional ICSI group was subdivided into ICSI-1 (semen suitable for in vitro fertilization, IVF) and ICSI-2 (poor semen quality) to minimize bias from differences in semen quality. Pregnancy, delivery and neonatal outcomes were compared between groups. RESULTS: There was a higher rate of polyspermy and a lower rate of top-quality embryos (TQE) on day 3 for oocytes subject to rescue ICSI compared with conventional ICSI. This reduced the total number of TQE and the number of TQE transferred in the rescue ICSI group. There was no significant difference between groups in clinical pregnancy, ongoing pregnancy, early miscarriage and live birth. For pregnant women, gestational age, route of delivery, risk of preterm birth and gestational diabetes mellitus were also comparable. Neonatal outcomes including sex ratio, birth weight, neonatal intensive care unit admission and birth defects were also similar after rescue and conventional ICSI. Moreover, no differences were observed with the different ICSI subgroups. CONCLUSIONS: For women with primary infertility who have a high risk of IVF fertilization failure (FF), rescue ICSI provides a safe and efficient alternative to minimize FF after initial IVF, but results in fewer TQE on day 3.


Assuntos
Infertilidade Feminina , Injeções de Esperma Intracitoplásmicas , Adulto , Transferência Embrionária , Feminino , Humanos , Gravidez , Resultado da Gravidez , Estudos Retrospectivos
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