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1.
Biochim Biophys Acta Mol Basis Dis ; 1870(1): 166885, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37714499

RESUMO

Perioperative hyperoxia therapy is of great significance to save the lives of patients, but little is known about the possible mechanisms that induce hyperoxia-induced acute lung injury (HALI) and the measures for clinical prevention and treatment. In this experiment, the models were established with a feeding chamber with automatic regulation of oxygen concentration. The results showed that with the increase in inhaled oxygen concentration and the prolongation of exposure time, the severity of lung injury also increases significantly, reaching the diagnostic indication of HALI after 48 h of inhaling 95 % oxygen concentration. Subsequently, according to the dynamic changes of apoptosis in lung specimens, and the expression changes in Sig-1R-regulated ER stress pathway proteins (Sig-1R, GRP78, p-PERK, ATF6, IRE1, Caspase-12, ATF4, CHOP, Caspase-3 and p-JNK), it was confirmed that the Sig-1R-regulated ER stress signaling pathway was involved in the occurrence of HALI. To explore the preventive and therapeutic effects of routine clinical medication on HALI during the perioperative period, our research group selected dexmedetomidine (Dex) with lung protection. The experimental results revealed that Dex partially reversed the changes in the expression levels of Sig-1R-regulated ER stress pathway proteins. These results preliminarily confirmed that Dex may inhibit apoptosis induced by high oxygen concentration through the Sig-1R-regulated ER stress signaling pathway, thus playing a protective role in HALI.


Assuntos
Lesão Pulmonar Aguda , Dexmedetomidina , Hiperóxia , Humanos , Dexmedetomidina/farmacologia , Dexmedetomidina/uso terapêutico , Hiperóxia/complicações , Estresse do Retículo Endoplasmático , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/prevenção & controle , Oxigênio , Receptor Sigma-1
2.
J Agric Food Chem ; 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37909421

RESUMO

Dietary restriction of l-methionine, an essential amino acid, exerts potent antitumor effects on l-methionine-dependent cancers. However, dietary restriction of l-methionine has not been practical for human therapy because of the problem with the administration of l-methionine concentration in foods. Here, a thermophilic methionine γ-lyase (MGL), that catalyzes the cleavage of the C-S bond in l-methionine to produce α-ketobutyric acid, methanethiol, and ammonia was engineered from human cystathionine γ-lyase and almost completely depleted l-methionine at 65 °C, a temperature that accelerates the volatilization of methanethiol and its oxidation products. The high efficiency of l-methionine lysis may be attributed to the cooperative fluctuation and moderate the structural rigidity of 4 monomers in the thermophilic MGL, which facilitates l-methionine access to the entrance of the active site. Experimental diets treated with thermophilic MGL markedly inhibited prostate tumor growth in mice, and in parallel, the in vivo concentrations of l-methionine, its transformation product l-cysteine, and the oxidative stress indicator malondialdehyde significantly decreased. These findings provide a technology for the depletion of l-methionine in foods with an engineered thermophilic MGL, which efficiently inhibits tumor growth in mice.

3.
RSC Adv ; 13(7): 4729-4745, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36760302

RESUMO

Photocatalytic oxidation (PCO) based on semiconductors offers a sustainable and promising way for environmental remediation. However, the photocatalytic performance currently suffers from weak light-harvesting ability, rapid charge combination and a lack of accessible reactive sites. Ultrathin two-dimensional (2D) materials are ideal candidates to overcome these problems and become hotpots in the research fields. Herein, we demonstrate an ultrathin (<4 nm thick) Na-doped BiOCl nanosheets with {001} facets (Na-BOC-001) fabricated via a facile bottom-up approach. Because of the synergistic effect of highly exposed active facets and optimal Na doping on the electronic and crystal structure, the Na-BOC-001 showed an upshifted conduction band (CB) with stronger reduction potential for O2 activation, more defective surface for enhanced O2 adsorption, as well as the highest visible-light driven charge separation and transfer ability. Compared with the bulk counterparts (BOC-010 and BOC-001), the largest amount of active species and the best photocatalytic performance for the tetracycline hydrochloride (TC) degradation were achieved for the Na-BOC-001 under visible-light irradiation, even though it had slightly weaker visible-light absorption ability. Moreover, the effect of the Na doping and crystal facet on the possible pathways for TC degradation was investigated. This work offers a feasible and economic strategy for the construction of highly efficient ultrathin 2D materials.

4.
Dev Cell ; 57(7): 901-913.e4, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35413238

RESUMO

The switch from mitosis to meiosis ensures the successive formation of gametes. However, it remains unclear how meiotic initiation occurs within the context of chromatin. Recent studies have shown that zinc finger HIT-type containing 1 (Znhit1), a subunit of the SRCAP chromatin remodeling complex, plays essential roles in modulating the chromatin structure. Herein, we report that the germline-conditional deletion of Znhit1 in male mice specifically blocks meiotic initiation. We show that Znhit1 is required for meiotic prophase events, including synapsis, DNA double-strand break formation, and meiotic DNA replication. Mechanistically, Znhit1 controls the histone variant H2A.Z deposition, which facilitates the expression of meiotic genes, such as Meiosin, but not the expression of Stra8. Interestingly, Znhit1 deficiency disrupts the transcription bubbles of meiotic genes. Thus, our findings identify the essential role of Znhit1-dependent H2A.Z deposition in allowing activation of meiotic gene expression, thereby controlling the initiation of meiosis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Transporte , Células Germinativas , Meiose , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Cromatina , Expressão Gênica , Células Germinativas/metabolismo , Histonas/metabolismo , Masculino , Meiose/genética , Camundongos
5.
Front Cell Dev Biol ; 9: 666303, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34631693

RESUMO

The WNT signaling pathway plays a crucial role in oviduct/fallopian development. However, the specific physiological processes regulated by the WNT pathway in the fallopian/oviduct function remain obscure. Benefiting from the Lgr4 knockout mouse model, we report the regulation of oviduct epithelial secretion by LGR4. Specifically, the loss of Lgr4 altered the mouse oviduct size and weight, severely reduced the number of oviductal epithelial cells, and ultimately impaired the epithelial secretion. These alterations were mediated by a failure of CTNNB1 protein accumulation in the oviductal epithelial cytoplasm, by the modulation of WNT pathways, and subsequently by a profound change of the gene expression profile of epithelial cells. In addition, selective activation of the WNT pathway triggered the expression of steroidogenic genes, like Cyp11a1 and 3ß-Hsd1, through the activation of the transcriptional factor NR5A2 in an oviduct primary cell culture system. As demonstrated, the LGR4 protein modulates a WNT-NR5A2 signaling cascade facilitating epithelial secretory cell maturation and steroidogenesis to safeguard oviduct development and function in mice.

6.
J Coll Physicians Surg Pak ; 31(9): 1051-1056, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34500520

RESUMO

OBJECTIVE: To investigate the expression of chromobox 2 (CBX2) in colorectal adenoma (CRA) and colorectal cancer (CRC), and analyse its correlation with various clinicopathological parameters. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Pathology Department, Huashan Hospital, Fudan University, from December 2019 to December 2020. METHODOLOGY: The mRNA level of CBX2 in colorectal mucosa, CRA and CRC was evaluated in gene expression profiling interactive analysis (GEPIA) and gene expression omnibus (GEO) dataset, then verified by quantitative real-time PCR (qRT-PCR). CBX2 expression by immunohistochemistry was determined in 122 samples, then its correlation was analysed with various clinicopathological parameters. Diagnostic value of CBX2 was estimated by the receiver operating characteristic curve (ROC). Prognostic value of CBX2 mRNA expression was evaluated via the Kaplan-Meier method in GEPIA. RESULTS: CBX2 expression rate in CRC (89.8%) was greater than adenoma (37.74%) and mucosa (20%). CBX2 protein levels were highest in adenocarcinoma and lowest in mucosa with intermediate level in adenoma. The area under curve (AUC) of CBX2 was 0.810 and 0.734, respectively, in distinguishing CRA from mucosa and CRC from CRA. CBX2 hyperexpression was not significantly correlated with clinicopathological variables, either in CRA or CRC. Kaplan-Meier survival analysis revealed that CBX2 mRNA hyperexpression was not associated with overall survival (OS) of CRC. Although the disease-free survival (DFS) of high CBX2 patients was shorter than those with low expression, but no obvious significance was found in colon adenocarcinoma (COAD, p=0.052) and rectal adenocarcinoma (READ, p=0.097). CONCLUSION: CBX2 expression progressively increased in the sequence of mucosa-adenoma-carcinoma, which may be used as a diagnostic biomarker and therapeutic target for CRA and CRC. Key Words: CBX2, Colorectal adenoma, Colorectal cancer, Biomarker.


Assuntos
Adenocarcinoma , Adenoma , Carcinoma , Neoplasias Colorretais , Complexo Repressor Polycomb 1/genética , Adenocarcinoma/genética , Adenoma/genética , Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Humanos , Mucosa , Prognóstico
7.
J Clin Lab Anal ; 35(10): e23961, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34477243

RESUMO

BACKGROUND: Colorectal adenoma (CRA) is a classical premalignant lesion, with high incidence and mainly coexisting with hyperplastic polyp (HPP). Hence, this study aimed to distinguish CRA from HPP by molecular expression profiling and advance the prevention of CRA and its malignance. METHODS: CRA and paired HPP biopsies were collected by endoscopy. Through RNA-sequencing (RNA-seq), the differentially expressed genes (DEGs) were obtained. Functional enrichment analysis was performed based on the DEGs. The STRING database and Cytoscape were used to construct the protein-protein interaction (PPI) network and perform module analysis. Hub genes were validated by real-time quantitative PCR (RT-qPCR) and immunohistochemistry. The ROC curve was drawn to establish the specificity of the hub genes. RESULTS: 485 significant DEGs were identified including 133 up-regulated and 352 down-regulated. The top 10 up-regulated genes were DLX5, MMP10, TAC1, ACAN, TAS2R38, WNT2, PHYHIPL, DKK4, DUSP27, and ABCA12. The top 10 down-regulated genes were SFRP2, CHRDL1, KBTBD12, RERGL, DPP10, CLCA4, GREM2, TMIGD1, FEV, and OTOP3. Wnt signaling pathway and extracellular matrix (ECM) were up-regulated in CRA. Three hub genes including WNT2, WNT5A, and SFRP1 were filtered out via Cytoscape. Further RT-qPCR and immunohistochemistry confirmed that WNT2 was highly expressed in CRA. The area under the ROC curve (AUC) at 0.98 indicated the expression level of WNT2 as a candidate to differ CRA from HPP. CONCLUSION: Our study suggests Wnt signaling pathway and ECM are enriched in CRA, and WNT2 may be used as a novel biomarker for distinguishing CRA from HPP and preventing the malignance of CRA.


Assuntos
Neoplasias Colorretais , Proteína Wnt2 , Idoso , Pólipos do Colo/diagnóstico , Pólipos do Colo/genética , Pólipos do Colo/metabolismo , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Biologia Computacional , Diagnóstico Diferencial , Matriz Extracelular/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mapas de Interação de Proteínas/genética , Transcriptoma/genética , Via de Sinalização Wnt/genética , Proteína Wnt2/genética , Proteína Wnt2/metabolismo
8.
J Mater Chem B ; 9(26): 5195-5220, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34128039

RESUMO

Bioimaging and biosensing have garnered interest in early cancer diagnosis due to the ability of gaining in-depth insights into cellular functions and providing a wide range of diagnostic parameters. Emerging 2D materials of multielement MXenes and monoelement black phosphorous nanosheets (BPNSs) with unique intrinsic physicochemical properties such as a tunable bandgap and layer-dependent fluorescence, high carrier mobility and transport anisotropy, efficient fluorescence quenching capability, desirable light absorption and thermoelastic properties, and excellent biocompatibility and biosafety properties provide promising nano-platforms for bioimaging and biosensing applications. In view of the growing attention on the rising stars of the post-graphene age in the progress of bioimaging and biosensing, and their common feature characteristics as well as complementarity for constructing complexes, the main objective of this review is to reveal the recent advances in the design of MXene or BPNS based nanoplatforms in the field of bioimaging and biosensing. The preparation and surface functionalization methods, biosafety, and other important aspects of bioimaging and biosensing applications of MXenes and BPNSs have been assessed systematically, along with highlighting the main challenges in further biomedical application. The review not only focuses on the advancements in 2D materials for use in bioimaging and biosensing but also assesses the possibility of their future potential in bioapplications.


Assuntos
Materiais Biocompatíveis/química , Técnicas Biossensoriais , Nanoestruturas/química , Imagem Óptica , Fósforo/química , Teste de Materiais
9.
Front Pharmacol ; 12: 609693, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995012

RESUMO

Berberine (BBR) has a neuroprotective effect against ischemic stroke, but its specific protective mechanism has not been clearly elaborated. This study explored the effect of BBR on the canopy FGF signaling regulator 2 (CNPY2) signaling pathway in the ischemic penumbra of rats. The model of cerebral ischemia-reperfusion injury (CIRI) was established by the thread embolization method, and BBR was gastrically perfused for 48 h or 24 h before operation and 6 h after operation. The rats were randomly divided into four groups: the Sham group, BBR group, CIRI group, and CIRI + BBR group. After 2 h of ischemia, followed by 24 h of reperfusion, we confirmed the neurologic dysfunction and apoptosis induced by CIRI in rats (p < 0.05). In the ischemic penumbra, the expression levels of CNPY2-regulated endoplasmic reticulum stress-induced apoptosis proteins (CNPY2, glucose-regulated protein 78 (GRP78), double-stranded RNA-activated protein kinase-like ER kinase (PERK), C/EBP homologous protein (CHOP), and Caspase-3) were significantly increased, but these levels were decreased after BBR treatment (p < 0.05). To further verify the inhibitory effect of BBR on CIRI-induced neuronal apoptosis, we added an endoplasmic reticulum-specific agonist and a PERK inhibitor to the treatment. BBR was shown to significantly inhibit the expression of apoptotic proteins induced by endoplasmic reticulum stress agonist, while the PERK inhibitor partially reversed the ability of BBR to inhibit apoptotic protein (p < 0.05). These results confirm that berberine may inhibit CIRI-induced neuronal apoptosis by downregulating the CNPY2 signaling pathway, thereby exerting a neuroprotective effect.

10.
Mucosal Immunol ; 14(4): 873-886, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33785873

RESUMO

Intestinal exocrine secretory lineages, including goblet cells and Paneth cells, provide vital innate host defense to pathogens. However, how these cells are specified and maintained to ensure intestinal barrier function remains poorly defined. Here we show that endoplasmic reticulum membrane protein complex subunit 3 (Emc3) is essential for differentiation and function of exocrine secretory lineages. Deletion of Emc3 in intestinal epithelium decreases mucus production by goblet cells and Paneth cell population, along with gut microbial dysbiosis, which result in spontaneous inflammation and increased susceptibility to DSS-induced colitis. Moreover, Emc3 deletion impairs stem cell niche function of Paneth cells, thus resulting in intestinal organoid culture failure. Mechanistically, Emc3 deficiency leads to increased endoplasmic reticulum (ER) stress. Mitigating ER stress with tauroursodeoxycholate acid alleviates secretory dysfunction and restores organoid formation. Our study identifies a dominant role of Emc3 in maintaining intestinal mucosal homeostasis.


Assuntos
Homeostase , Mucosa Intestinal/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Via Secretória , Animais , Colite/etiologia , Colite/metabolismo , Colite/patologia , Suscetibilidade a Doenças , Células Caliciformes/metabolismo , Masculino , Camundongos , Celulas de Paneth/metabolismo , Permeabilidade
11.
Adv Sci (Weinh) ; 8(4): 2002465, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33643789

RESUMO

A metal-complex-modified graphitic carbon nitride (g-C3N4) bulk heterostructure is presented here as a promising alternative to high-cost noble metals as artificial photocatalysts. Theoretical and experimental studies of the spectral and physicochemical properties of three structurally similar molecules Fo-D, Pt-D, and Pt-P confirm that the Pt(II) acetylide group effectively expands the electron delocalization and adjusts the molecular orbital levels to form a relatively narrow bandgap. Using these molecules, the donor-acceptor assemblies Fo-D@CN, Pt-D@CN, and Pt-P@CN are formed with g-C3N4. Among these assemblies, the Pt(II) acetylide-based composite materials Pt-D@CN and Pt-P@CN with bulk heterojunction morphologies and extremely low Pt weight ratios of 0.19% and 0.24%, respectively, exhibit the fastest charge transfer and best light-harvesting efficiencies. Among the tested assemblies, 10 mg Pt-P@CN without any Pt metal additives exhibits a significantly improved photocatalytic H2 generation rate of 1.38 µmol h-1 under simulated sunlight irradiation (AM1.5G, filter), which is sixfold higher than that of the pristine g-C3N4.

12.
Theranostics ; 11(5): 2137-2148, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33500716

RESUMO

Aggregation induced emission (AIE)-active bright two-photon fluorescent probes with second near-infrared (NIR-II) light excitability can be used for efficient brain bioimaging studies, wherein the fabrication of water-dispersible nanoparticles by encapsulating the hydrophobic probes with amphiphilic polymer holds the key to ensuring biocompatibility and in vivo adaptability. However, barely any study has evaluated the structural requirements that can substantially affect the water-dispersible nanoparticle formation ability of an organic AIE-active dye with amphiphilic polymers. The present study systematically assessed the structural dependency of a well-known acrylonitrile based AIE system/fluorogenic core upon the formation of water-dispersible nanoparticles and elucidated how the structural modifications can impact the in vivo two-photon imaging. Methods: A total of four acrylonitrile-based aggregation induced emission (AIE)-active two-photon (TP) fluorescent probes (AIETP, AIETP C1, AIETP C2 and AIETP C3) have been judiciously designed and synthesized with structural variations to realize how the structural alterations could substantially influence the water-dispersible nanoparticle formation ability (with amphiphilic polymers) and photo-stability to impact the in vivo imaging. Results: It has been found that the incorporation of the phenyl-thiazole unit in AIETP, AIETP C2 and AIETP C3 facilitated the formation of water-dispersible nanoparticles (NPs) with amphiphilic polymers (Pluronic F127) whereas the presence of only phenyl moiety instead in AIETP C1 could not meet the suitable condition to form the NPs with good aqueous dispersibility. Rationally designed AIETP NPs that exhibited higher brightness, improved photostability and good two-photon absorption cross section was successfully employed for in vivo brain vasculature imaging. Conclusions: Robust noninvasive 2D and 3D two-photon (NIR-II light, 1040 nm) brain vasculature imaging with beneficial attributes such as outstanding penetration depth (800 µm) and exceptional spatial resolution (1.92 µm), were achieved by utilizing AIETP NPs in this study.


Assuntos
Encéfalo/irrigação sanguínea , Corantes Fluorescentes/química , Nanopartículas/química , Imagem Óptica/métodos , Fótons , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Apoptose , Encéfalo/patologia , Proliferação de Células , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Poloxâmero/química , Polímeros/química
13.
Anal Chem ; 93(4): 2596-2602, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33464055

RESUMO

Mitochondria are highly dynamic organelles with interconnected tubule structures that are sensitive to environmental stress and light illumination. Super-resolution optical imaging of mitochondrial dynamics is of significance for understanding such biological events. Direct stochastic optical reconstruction microscopy has the advantages of a high spatial resolution, low phototoxicity in live-cell imaging, and the capacity to incorporate smart fluorescent probes. However, dSTORM imaging in live cells is challenging because of the requirement for an imaging buffer and a low temporal resolution. In this work, we achieved dSTORM imaging of mitochondrial dynamics in live cells with a disulfide-substituted Cy5 probe without using any toxic imaging buffer. Under the illumination of very low laser power, the probe exhibited spontaneous photoblinking triggered by disulfide-bond reduction in mitochondria of live cells. The obtained thiol attacked nearby carbon to form a six-membered ring and the reversible opening/closing of the ring produced spontaneous photoblinking behavior. With this new STORM strategy, we achieved observation of mitochondrial dynamics for more than 3 min, which provides a promising tool for further studies of mitochondria with an ultrafine structure.


Assuntos
Dissulfetos/química , Corantes Fluorescentes/química , Mitocôndrias/fisiologia , Nanotecnologia/métodos , Análise de Célula Única/métodos , Células HeLa , Humanos , Imagem Molecular , Estrutura Molecular , Processos Fotoquímicos
14.
Molecules ; 25(3)2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32013190

RESUMO

Two probes, AIE-1 and AIE-2, were synthesized to investigate the effect of substitutional functional group on aggregation (aggregation-caused quenching (ACQ) or aggregation-induced emission (AIE)) and intramolecular charge transfer (ICT) behavior as well as on the cell imaging aspect. The yellow-color non-substituted probe AIE-1 showed weak charge-transfer absorption and an emission band at 377 nm and 432 nm, whereas the yellowish-orange color substituted probe AIE-2 showed a strong charge-transfer absorption and an emission band at 424 nm and 477 nm in THF solvent. The UV-Vis studies of AIE-1 and AIE-2 in THF and THF with different water fractions showed huge absorption changes in AIE-2 with high water fractions due to its strong aggregation behavior, but no such noticeable absorption changes were observed for AIE-1. Interestingly, the fluorescence intensity of AIE-1 at 432 nm gradually decreased with increasing water fractions and became almost non-emissive at 90% water. However, the monomer-type emission of AIE-2 at 477 nm was shifted to 584 nm with a 6-fold increase in fluorescence intensity in THF-H2O (1:9, v/v) solvent mixtures due to the restriction of intramolecular rotation on aggregation in high water fractions. This result indicates that the probe AIE-1 shows ACQ and probe AIE-2 shows AIE behaviors in THF-H2O solvent mixtures. Furthermore, the emission spectra of AIE-1 and AIE-2 were carried out in different solvent and with different concentrations to see the solvent- or concentration-dependent aggregation behavior. Scanning electron microscope (SEM) and dynamic light scattering (DLS) experiments were also conducted to assess the morphology and particle size of two probes before and after aggregation. Both of the probes, AIE-1 and AIE-2, showed less toxicity on HeLa cells and were suitable for cell imaging studies. Density functional theory (DFT) calculation was also carried out to confirm the ICT process from an electron-rich indole moiety to an electron-deficient cyano-phenyl ring of AIE-1 or AIE-2.


Assuntos
Fluorescência , Corantes Fluorescentes/química , Acetonitrilas/química , Aldeídos/química , Sobrevivência Celular/efeitos dos fármacos , Citotoxinas/química , Diagnóstico por Imagem , Elétrons , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HeLa , Humanos , Microscopia Eletroquímica de Varredura , Processos Fotoquímicos , Espalhamento de Radiação , Solventes , Espectrometria de Fluorescência
15.
Front Optoelectron ; 13(4): 318-326, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36641564

RESUMO

As a new method of cell-cell communication, tunneling nanotubes (TNTs) play important roles in cell-cell signaling and mass exchanges. However, a lack of powerful tools to visualize dynamic TNTs with high temporal/spatial resolution restricts the exploration of their formation and cleavage, hindering the complete understanding of its mechanism. Herein, we present the first example of using stochastic optical reconstruction microscopy (STORM) to observe the tube-like structures of TNTs linking live cells with an easily prepared fluorescent dye. Because of this new imaging microscopy, the cleavage process of TNTs was observed with a high spatial resolution.

16.
Anal Chem ; 92(1): 1541-1548, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31760749

RESUMO

A versatile twisted-intramolecular-charge-transfer (TICT)-based near-infrared (NIR) fluorescent probe (L) has been judiciously designed and synthesized that could be utilized for potential cancer diagnosis and to track lymph node(s) in mice through distinct emission signals. Essentially, the probe rendered the capability to preferentially recognize the cancer cells over the noncancer cells by polarity-guided lipid droplet specific differential bioimaging (in green emission channel) studies. The probe also exhibited selective turn-on fluorescence response toward HSA/BSA in physiological media (aqueous PBS buffer; pH 7.4) at far-red/NIR regions, because of the 1:1 chelation between the probe and HSA/BSA. Therefore, the fluorescent probe was then maneuvered to track the draining lymphatic system and sentinel lymph node in tumor mice model by fluorescence imaging (NIR/deep-red channel), wherein the accumulated albumin protein in the draining tumor lymphatic system facilitated the in situ formation of the fluorescent albumin-L complex.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Corantes Fluorescentes/química , Linfonodos/diagnóstico por imagem , Sistema Linfático/diagnóstico por imagem , Imagem Óptica , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Corantes Fluorescentes/síntese química , Camundongos , Estrutura Molecular
17.
Exp Ther Med ; 18(2): 1299-1308, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31316621

RESUMO

The present study aimed to investigate the antispasmodic effect of higenamine on cold-induced cutaneous vasoconstriction and the underlying molecular mechanisms. A cold-induced cutaneous vasoconstriction rat model was established and different doses of higenamine were delivered by intravenous injection. The changes of cutaneous regional blood flow (RBF) between groups were analyzed. In vitro, the proliferation of human dermal microvascular endothelial cells was measured by MTT. The NO concentration was detected by a nitrate reductase assay. Flow cytometry was applied to measure reactive oxygen species (ROS) levels. The protein expression levels were detected by western blotting. The results demonstrated that in the model group, RBF declined compared with the normal control group, but was reversed by treatment with higenamine. The expression of endothelial nitric oxide synthase (eNOS), phosphorylated (p)-eNOS, protein kinase B (Akt1), p-Akt1, AMP-activated protein kinase (AMPK) α1 and p-AMPKα1 was upregulated by hypothermic treatment but was reversed by higenamine treatment. Treatment with higenamine significantly reduced the level of intracellular α2C-adrenoreceptor (AR) compared with the hypothermia group (P<0.05). Furthermore, the expression of twinfilin-1 (PTK9) was downregulated in the higenamine and positive control groups compared with the hypothermia group (P<0.05). Compared with the hypothermia group, the levels of ROS and α2C-AR (intracellular & membrane) were decreased in higenamine and the positive control group (P<0.05 and P<0.01, respectively). This study, to the best of our knowledge, is the first to assess the effects of higenamine on cold-induced vasoconstriction in vivo and its molecular mechanisms on the PI3K/Akt, AMPK/eNOS/nitric oxide, ROS/α2C-AR and PTK9 signaling pathways under hypothermia conditions. Higenamine may be a good therapeutic option for Raynaud's phenomenon (RP) and cold-induced vasoconstriction.

18.
Biomaterials ; 211: 25-47, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31078050

RESUMO

Lysosomes, an important organelle of eukaryotic cells, are covered with the cell membrane and contain an array of degradative enzymes. The disrupt in lysosomal functions may lead to the development of severe diseases. In nanotechnology, nanomaterials working mechanism and its biomedical output are highly dependent on the lysosomes as it plays a crucial role in intracellular transport. Several nanomaterials specifically designed for lysosome-related actions are highly advantageous in trafficking and delivering the loaded imaging/therapeutic agents. But for other applications, especially gene-based therapeutic delivery into the sub-organelles such as mitochondria and nucleus, lysosomal related degradation could be an obstacle to achieve a maximal therapeutic index. In order to understand the relationship between lysosomes and designed nanomaterials for kind of desired application in biomedical research, complete knowledge of their various designing strategies, size dependent or ligand supportive cellular uptake mechanisms, trafficking, and localizations in eukaryotic cells is highly desired. In this review, we intended to discuss various nanomaterial types that have been applied in biomedical applications based on lysosomal internalization and escape from endo/lysosomes and explored their related advantages/disadvantages. Additionally, we also deliberated nanomaterials direct translocation mechanism, their autophagic accumulation and the underlying mechanism to induced autophagy. Finally, some challenges and critical issues in current research from clinical application perspective has also been addressed. Great understanding of these factors will help in understanding and facilitating the development of safe and effective lysosomal related nanomaterial-based imaging/therapeutic systems for future applications.


Assuntos
Lisossomos/metabolismo , Nanomedicina/métodos , Nanoestruturas/uso terapêutico , Animais , Autofagia , Sistemas de Liberação de Medicamentos/métodos , Endocitose , Humanos , Nanoestruturas/química , Nanotecnologia/métodos
19.
Materials (Basel) ; 12(8)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31018561

RESUMO

Glass fiber reinforced polyolefin composite materials have many advantages regarding their performance and have been widely used in many fields. However, there are few reports on the simultaneously bidirectional self-enhancement of glass fiber reinforced polyethylene/polypropylene composite pipe. To self-reinforce the pipe's circular and axial properties simultaneously, short glass fiber reinforced high-density polyethylene/polypropylene (SGF/HDPE/PP) pipes were extruded using a shearing-drawing two-dimensional compound stress field pipe-extrusion device. The effects of the rotating speed of the rotating shear sleeve on the orientation, heat behavior, microstructure, and tensile strength of the pipe were investigated in this paper. The microstructure was observed using scanning electron microscopy (SEM), and the crystal diffraction was analyzed using a polycrystalline X-ray diffractometer (WAXD), the heat behavior was measured using a differential scanning calorimeter (DSC), and the tensile strength was tested using a universal electronic tensile testing machine. The results showed that the shear induction effect induced by the shear rotating promoted the formation of the oriented structure of the crystal plate and SGFs along the circular and axial directions of the pipe simultaneously. Furthermore, it increased the crystallinity of the system, and self-improved the pipe's circular and axial tensile strength at the same time.

20.
J Cell Sci ; 131(10)2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29700203

RESUMO

Heparan sulfate proteoglycans (HSPGs) have been shown to regulate various developmental processes. However, the function of heparan sulfate (HS) during the development of mammalian stomach has not been characterized yet. Here, we investigate the role of epithelial HS in embryonic stomach by examining mice deficient in the glycosyltransferase gene Ext1 We show that HS exhibits a specific and dynamic expression pattern in mouse embryonic stomach. Depletion of the epithelial HS leads to stomach hypoplasia, with phenotypic differences in the gastric mucosa between the forestomach and hindstomach. In the posterior stomach, HS depletion disrupts glandular stomach patterning and cytodifferentiation via attenuation of Fgf signaling activity. Inhibition of Fgf signaling in vitro recapitulates the patterning defect. Ligand and carbohydrate engagement assay (LACE) reveals a diminished assembly of Fgf10 and Fgfr2b in the mutant. In the anterior stomach, loss of epithelial HS leads to stratification and differentiation defects of the multilayered squamous epithelium, along with reduced Hh and Bmp signaling activity. Our data demonstrate that epithelial HS plays multiple roles in regulating mammalian stomach morphogenesis in a regional-specific manner.


Assuntos
Epitélio/metabolismo , Heparitina Sulfato/metabolismo , Estômago/embriologia , Animais , Epitélio/embriologia , Feminino , Fator 10 de Crescimento de Fibroblastos/genética , Fator 10 de Crescimento de Fibroblastos/metabolismo , Mucosa Gástrica/metabolismo , Masculino , Camundongos , Camundongos Knockout , Morfogênese , N-Acetilglucosaminiltransferases/genética , N-Acetilglucosaminiltransferases/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo
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