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1.
bioRxiv ; 2024 Apr 04.
Article de Anglais | MEDLINE | ID: mdl-38617314

RÉSUMÉ

How genetic lesions drive cell transformation and whether they can be circumvented without compromising function of non-transformed cells are enduring questions in oncology. Here we show that in mature T cells-in which physiologic clonal proliferation is a cardinal feature- constitutive MYC transcription and Tsc1 loss in mice modeled aggressive human malignancy by reinforcing each other's oncogenic programs. This cooperation was supported by MYC-induced large neutral amino acid transporter chaperone SLC3A2 and dietary leucine, which in synergy with Tsc1 deletion overstimulated mTORC1 to promote mitochondrial fitness and MYC protein overexpression in a positive feedback circuit. A low leucine diet was therapeutic even in late-stage disease but did not hinder T cell immunity to infectious challenge, nor impede T cell transformation driven by constitutive nutrient mTORC1 signaling via Depdc5 loss. Thus, mTORC1 signaling hypersensitivity to leucine as an onco-nutrient enables an onco-circuit, decoupling pathologic from physiologic utilization of nutrient acquisition pathways.

2.
IEEE Robot Autom Lett ; 9(3): 2104-2111, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38313832

RÉSUMÉ

Lower-limb wearable robots designed to assist people in everyday activities must reliably recover from any momentary confusion about what the user is doing. Such confusion might arise from momentary sensor failure, collision with an obstacle, losing track of gait due to an out-of-distribution stride, etc. Systems that infer a user's walking condition from angle measurements using Bayesian filters (e.g., extended Kalman filters) have been shown to accurately track gait across a range of activities. However, due to the fundamental problem structure and assumptions of Bayesian filter implementations, such estimators risk becoming 'lost' with little hope of a quick recovery. In this paper, we 1) introduce a Monte Carlo-based metric to quantify the robustness of pattern-tracking gait estimators, 2) propose strategies for improving tracking robustness, and 3) systematically evaluate them against this new metric using a publicly available gait biomechanics dataset. Our results, aggregating 2,700 trials of simulated walking of 10 able-bodied subjects under random perturbations, suggest that drastic improvements in robustness (from 8.9% to 99%) are possible using relatively simple modifications to the estimation process without noticeably degrading estimator accuracy.

3.
Immunity ; 56(11): 2555-2569.e5, 2023 Nov 14.
Article de Anglais | MEDLINE | ID: mdl-37967531

RÉSUMÉ

Tumors develop by invoking a supportive environment characterized by aberrant angiogenesis and infiltration of tumor-associated macrophages (TAMs). In a transgenic model of breast cancer, we found that TAMs localized to the tumor parenchyma and were smaller than mammary tissue macrophages. TAMs had low activity of the metabolic regulator mammalian/mechanistic target of rapamycin complex 1 (mTORC1), and depletion of negative regulator of mTORC1 signaling, tuberous sclerosis complex 1 (TSC1), in TAMs inhibited tumor growth in a manner independent of adaptive lymphocytes. Whereas wild-type TAMs exhibited inflammatory and angiogenic gene expression profiles, TSC1-deficient TAMs had a pro-resolving phenotype. TSC1-deficient TAMs relocated to a perivascular niche, depleted protein C receptor (PROCR)-expressing endovascular endothelial progenitor cells, and rectified the hyperpermeable blood vasculature, causing tumor tissue hypoxia and cancer cell death. TSC1-deficient TAMs were metabolically active and effectively eliminated PROCR-expressing endothelial cells in cell competition experiments. Thus, TAMs exhibit a TSC1-dependent mTORC1-low state, and increasing mTORC1 signaling promotes a pro-resolving state that suppresses tumor growth, defining an innate immune tumor suppression pathway that may be exploited for cancer immunotherapy.


Sujet(s)
Progéniteurs endothéliaux , Protéines suppresseurs de tumeurs , Animaux , Humains , Sérine-thréonine kinases TOR/métabolisme , Protéine-1 du complexe de la sclérose tubéreuse/génétique , Macrophages associés aux tumeurs/métabolisme , Progéniteurs endothéliaux/métabolisme , Récepteur endothélial de la protéine C , Complexe-1 cible mécanistique de la rapamycine , Néovascularisation pathologique , Mammifères
4.
J Biomed Opt ; 28(9): 096005, 2023 09.
Article de Anglais | MEDLINE | ID: mdl-37720189

RÉSUMÉ

Significance: An integrated cellular-resolution optical coherence tomography (OCT) module with near-infrared Raman spectroscopy was developed on the discrimination of various skin cancer cells and normal cells. Micron-level three-dimensional (3D) spatial resolution and the spectroscopic capability on chemical component determination can be obtained simultaneously. Aim: We experimentally verified the effectiveness of morphology, intensity, and spectroscopy features for discriminating skin cells. Approach: Both spatial and spectroscopic features were employed for the discrimination of five types of skin cells, including keratinocytes (HaCaT), the cell line of squamous cell carcinoma (A431), the cell line of basal cell carcinoma (BCC-1/KMC), primary melanocytes, and the cell line of melanoma (A375). The cell volume, compactness, surface roughness, average intensity, and internal intensity standard deviation were extracted from the 3D OCT images. After removing the fluorescence components from the acquired Raman spectra, the entire spectra (600 to 2100 cm-1) were used. Results: An accuracy of 85% in classifying five types of skin cells was achieved. The cellular-resolution OCT images effectively differentiate cancer and normal cells, whereas Raman spectroscopy can distinguish the cancer cells with nearly 100% accuracy. Conclusions: Among the OCT image features, cell surface roughness, internal average intensity, and standard deviation of internal intensity distribution effectively differentiate the cancerous and normal cells. The three features also worked well in sorting the keratinocyte and melanocyte. Using the full Raman spectra, the melanoma and keratinocyte-based cell carcinoma cancer cells can be discriminated effectively.


Sujet(s)
Carcinome basocellulaire , Mélanome , Tumeurs cutanées , Humains , Tomographie par cohérence optique , Analyse spectrale Raman , Tumeurs cutanées/imagerie diagnostique , Carcinome basocellulaire/imagerie diagnostique , Mélanome/imagerie diagnostique , Apprentissage machine
5.
Chem Commun (Camb) ; 59(71): 10660-10663, 2023 Aug 31.
Article de Anglais | MEDLINE | ID: mdl-37581279

RÉSUMÉ

Piperic acid derivatives were found to affect the islet amyloid polypeptide (IAPP) aggregation process. Structure-activity relationship studies revealed that PAD-13 was an efficient molecular modulator to accelerate IAPP fibril formation by promoting primary and secondary nucleation and reducing its antimicrobial activity.


Sujet(s)
Anti-infectieux , Polypeptide amyloïde des ilots , Polypeptide amyloïde des ilots/pharmacologie , Polypeptide amyloïde des ilots/composition chimique , Amyloïde/composition chimique , Acides gras insaturés , Anti-infectieux/pharmacologie
6.
J Appl Crystallogr ; 56(Pt 4): 988-993, 2023 Aug 01.
Article de Anglais | MEDLINE | ID: mdl-37555211

RÉSUMÉ

Liposome development is of great interest owing to increasing requirements for efficient drug carriers. The structural features and thermal stability of such liposomes are crucial in drug transport and delivery. Reported here are the results of the structural characterization of PEGylated liposomes via small- and wide-angle X-ray scattering and an asymmetric flow field-flow fractionation (AF4) system coupled with differential refractive-index detection, multi-angle light scattering (MALS) and dynamic light scattering. This integrated analysis of the exemplar PEGylated liposome formed from hydrogenated soy phosphatid-yl-choline (HSPC) with the addition of cholesterol reveals an average hydro-dynamic radius (R h) of 52 nm with 10% polydispersity, a comparable radius of gyration (R g) and a major liposome particle mass of 118 kDa. The local bilayer structure of the liposome is found to have asymmetric electronic density profiles in the inner and outer leaflets, sandwiched by two PEGylated outer layers ca 5 nm thick. Cholesterol was found to effectively intervene in lipid chain packing, resulting in the thickening of the liposome bilayer, an increase in the area per lipid and an increase in liposome size, especially in the fluid phase of the liposome. These cholesterol effects show signs of saturation at cholesterol concentrations above ca 1:5 cholesterol:lipid molar ratio.

7.
Nature ; 619(7970): 616-623, 2023 Jul.
Article de Anglais | MEDLINE | ID: mdl-37380769

RÉSUMÉ

In metazoan organisms, cell competition acts as a quality control mechanism to eliminate unfit cells in favour of their more robust neighbours1,2. This mechanism has the potential to be maladapted, promoting the selection of aggressive cancer cells3-6. Tumours are metabolically active and are populated by stroma cells7,8, but how environmental factors affect cancer cell competition remains largely unknown. Here we show that tumour-associated macrophages (TAMs) can be dietarily or genetically reprogrammed to outcompete MYC-overexpressing cancer cells. In a mouse model of breast cancer, MYC overexpression resulted in an mTORC1-dependent 'winner' cancer cell state. A low-protein diet inhibited mTORC1 signalling in cancer cells and reduced tumour growth, owing unexpectedly to activation of the transcription factors TFEB and TFE3 and mTORC1 in TAMs. Diet-derived cytosolic amino acids are sensed by Rag GTPases through the GTPase-activating proteins GATOR1 and FLCN to control Rag GTPase effectors including TFEB and TFE39-14. Depletion of GATOR1 in TAMs suppressed the activation of TFEB, TFE3 and mTORC1 under the low-protein diet condition, causing accelerated tumour growth; conversely, depletion of FLCN or Rag GTPases in TAMs activated TFEB, TFE3 and mTORC1 under the normal protein diet condition, causing decelerated tumour growth. Furthermore, mTORC1 hyperactivation in TAMs and cancer cells and their competitive fitness were dependent on the endolysosomal engulfment regulator PIKfyve. Thus, noncanonical engulfment-mediated Rag GTPase-independent mTORC1 signalling in TAMs controls competition between TAMs and cancer cells, which defines a novel innate immune tumour suppression pathway that could be targeted for cancer therapy.


Sujet(s)
Compétition intercellulaire , Techniques de reprogrammation cellulaire , Immunité innée , Tumeurs , Macrophages associés aux tumeurs , Animaux , Souris , Acides aminés/métabolisme , Facteurs de transcription à motifs basiques hélice-boucle-hélice et à glissière à leucines/métabolisme , Compétition intercellulaire/génétique , Compétition intercellulaire/immunologie , Protéines alimentaires/pharmacologie , Modèles animaux de maladie humaine , dGTPases/métabolisme , Lysosomes/métabolisme , Complexe-1 cible mécanistique de la rapamycine/métabolisme , Tumeurs/génétique , Tumeurs/immunologie , Tumeurs/métabolisme , Tumeurs/anatomopathologie , Protéines proto-oncogènes c-myc/génétique , Protéines proto-oncogènes c-myc/métabolisme , Macrophages associés aux tumeurs/immunologie , Macrophages associés aux tumeurs/métabolisme
8.
J Am Chem Soc ; 145(23): 12459-12464, 2023 Jun 14.
Article de Anglais | MEDLINE | ID: mdl-37255463

RÉSUMÉ

The cis/trans stereochemistry of repeating alkenes in polymers provides a powerful handle to modulate the thermal and mechanical properties of these soft materials, but synthetic methods to precisely dictate this parameter remain scarce. We report herein a cis-selective acyclic diene metathesis (ADMET) polymerization of readily available α,ω-diene monomers with high functional group tolerance. Identification of a highly stereoselective cyclometalated Ru catalyst allowed the synthesis of a broad array of polymers with cis contents up to 99%. This platform was leveraged to study the impact of the cis geometry on the thermal and mechanical properties of polyalkenamers, including an ABA triblock copolymer synthesized via extension of a cis-rich telechelic polyoctenamer with d,l-lactide. These results suggest that cis-selective ADMET affords an efficient strategy to tune the properties of a variety of polymers.

9.
Nat Chem ; 15(1): 14-20, 2023 01.
Article de Anglais | MEDLINE | ID: mdl-36280767

RÉSUMÉ

The cis/trans geometry of olefins is known to dramatically influence the thermal and mechanical properties of polyalkenamers. Yet, polymerization methods that efficiently control this parameter are scarce. Here we report the development of a stereoretentive acyclic diene metathesis polymerization that uses the reactivity of dithiolate Ru carbenes combined with cis monomers. These Ru catalysts exhibit exquisite retention of the cis geometry and tolerate many polar functional groups, enabling the synthesis of all-cis polyesters, polycarbonates, polyethers and polysulfites. The stereoretentive acyclic diene metathesis polymerization is also characterized by low catalyst loadings and tolerance towards trans impurities in the monomer batch, which should facilitate large-scale implementation. Modulation of the reaction temperature and time leads to an erosion of stereoretention, permitting a stereocontrolled synthesis of polyalkenamers with predictable cis:trans ratios. The impact of the stereochemistry of the repeating alkenes on the thermal properties is clearly demonstrated through differential scanning calorimetry and thermogravimetric analysis.


Sujet(s)
Alcènes , Polyènes , Polymérisation , Alcènes/composition chimique , Température , Catalyse
10.
PLoS One ; 17(10): e0275450, 2022.
Article de Anglais | MEDLINE | ID: mdl-36194586

RÉSUMÉ

OBJECTIVE: This study investigated how peripheral axonal excitability changes in ischemic stroke patients with hemiparesis or hemiplegia, reflecting the plasticity of motor axons due to corticospinal tract alterations along the poststroke stage. METHODS: Each subject received a clinical evaluation, nerve conduction study, and nerve excitability test. Nerve excitability tests were performed on motor median nerves in paretic and non-paretic limbs in the acute stage of stroke. Control nerve excitability test data were obtained from age-matched control subjects. Some patients underwent excitability examinations several times in subacute or chronic stages. RESULTS: A total of thirty patients with acute ischemic stroke were enrolled. Eight patients were excluded due to severe entrapment neuropathy in the median nerve. The threshold current for 50% compound muscle action potential (CMAP) was higher in paretic limbs than in control subjects. Furthermore, in the cohort with severe patients (muscle power ≤ 3/5 in affected hands), increased threshold current for 50% CMAP and reduced subexcitability were noted in affected limbs than in unaffected limbs. In addition, in the subsequent study of those severe patients, threshold electrotonus increased in the hyperpolarization direction: TEh (100-109 ms), and the minimum I/V slope decreased. The above findings suggest the less excitable and less accommodation in lower motor axons in the paretic limb caused by ischemic stroke. CONCLUSION: Upper motor neuron injury after stroke can alter nerve excitability in lower motor neurons, and the changes are more obvious in severely paretic limbs. The accommodative changes of axons progress from the subacute to the chronic stage after stroke. Further investigation is necessary to explore the downstream effects of an upper motor neuron insult in the peripheral nerve system.


Sujet(s)
Accident vasculaire cérébral ischémique , Accident vasculaire cérébral , Potentiels d'action , Axones/physiologie , Humains , Nerf médian/physiologie , Plasticité neuronale , Accident vasculaire cérébral/complications
11.
J Phys Chem A ; 126(41): 7548-7556, 2022 Oct 20.
Article de Anglais | MEDLINE | ID: mdl-36217924

RÉSUMÉ

Machine learning predictions of molecular thermochemistry, such as formation enthalpy, have been limited for large and complicated species because of the lack of available training data. Such predictions would be important in the prediction of reaction thermodynamics and the construction of kinetic models. Herein, we introduce a graph-based deep learning approach that can separately learn the enthalpy contribution of each atom in its local environment with the effect of the overall molecular structure taken into account. Because this approach follows the additivity scheme of increment theory, it can be generalized to larger and more complicated species not present in the training data. By training the model on molecules with up to 11 heavy atoms, it can predict the formation enthalpy of testing molecules with up to 42 heavy atoms with a mean absolute error of 2 kcal/mol, which is less than half of the error of the conventional increment theory. We expect that this approach will also enable rapid prediction of other extensive properties of large molecules that are difficult to derive from experiments or ab initio calculation.

12.
Materials (Basel) ; 15(7)2022 Mar 22.
Article de Anglais | MEDLINE | ID: mdl-35407685

RÉSUMÉ

In this study, a negative replica layer of leaf surface microstructures was used to cover the top surfaces of semitransparent thin-film luminescent solar concentrators (LSCs) to enhance the concentrators' performance. With low reflection on the air-glass interface of the glass plate in a thin-film LSC, a negative replica layer enables the scattering of incident sunlight and increases the path of light transmitted into the LSC and the thin phosphor layer at the bottom surface of the LSC. The incident sunlight is therefore more likely to interact with the phosphor particles in the thin-film phosphor layer, thereby enhancing the performance of the LSC. In this study, semitransparent thin-film LSCs with different inorganic phosphors were examined. The experimental results revealed that the optical collection efficiency of semitransparent thin-film LSCs covered with negative replica layers of leaf surface microstructures was higher than that of the semitransparent thin-film LSCs without negative replica layers. Furthermore, the LSCs with negative replica layers with high haze ratios exhibited high optical collection efficiency. Integrating negative replica layers of leaf surface microstructures as semitransparent layers in thin-film LSCs may optimize the application of LSCs in building-integrated photovoltaics (BIPVs).

13.
J Biophotonics ; 15(1): e202100249, 2022 01.
Article de Anglais | MEDLINE | ID: mdl-34662510

RÉSUMÉ

With homemade active crystalline fibers, we generated bright and broadband light sources for full-field optical coherence tomography, offering deep penetration into skin tissues with cellular resolution at a high frame rate. Extraction of backscattered spectra from the tissue has potential applications in biomedicine. The hysteresis nonlinearity of the piezoelectric transducer actuating the Mirau interferometer has been greatly reduced by a feedforward compensation approach. The linearized hysteresis response enables us to extract depth-dependent spectra accurately. To validate, the complex dispersion of a fused silica plate was characterized with 2% error. Further validation on an in vitro setting, the backscattered spectra from indocyanine green pigment and nonpigmented microspheres were obtained and verified. For in vivo skin measurement, the backscattered spectra show depth-dependent spectral shift and bandwidth variation due to the complex skin anatomy and pigment absorption. Such a high-speed spectra acquisition of in vivo deep tissue backscattering could lead to disease diagnosis in clinical settings.


Sujet(s)
Peau , Tomographie par cohérence optique , Humains , Peau/imagerie diagnostique
14.
Trends Cancer ; 7(11): 1010-1019, 2021 11.
Article de Anglais | MEDLINE | ID: mdl-34305041

RÉSUMÉ

Investigation of cancer as a cell-level disease has led to the development of cancer cell-directed therapies including cytotoxic T lymphocyte (CTL)-based immunotherapy; yet, many patients are refractory to these modalities of cancer treatment and acquired resistance frequently occurs. Of note, cancer environment controls the manifestation of cancerous cell phenotype. Helper T (Th) cells orchestrate immune defense responses targeting cancer cells as well as the tumor microenvironment. Recent studies have shown that in addition to interferon (IFN)-γ-producing Th1 cells, interleukin (IL)-4-producing Th2 cells function as potent anticancer effectors in part by promoting tumor stroma reconfiguration and tumor tissue repair. Such Th cell-mediated tissue-level immunity may be harnessed for novel modalities of cancer environment immunotherapy.


Sujet(s)
Tumeurs , Lymphocytes auxiliaires Th1 , Humains , Tumeurs/thérapie , Lymphocytes T cytotoxiques , Lymphocytes T auxiliaires , Lymphocytes auxiliaires Th2 , Microenvironnement tumoral
15.
Cancer Metab ; 9(1): 12, 2021 Mar 24.
Article de Anglais | MEDLINE | ID: mdl-33762003

RÉSUMÉ

BACKGROUND: Fructose is an abundant source of carbon and energy for cells to use for metabolism, but only certain cell types use fructose to proliferate. Tumor cells that acquire the ability to metabolize fructose have a fitness advantage over their neighboring cells, but the proteins that mediate fructose metabolism in this context are unknown. Here, we investigated the determinants of fructose-mediated cell proliferation. METHODS: Live cell imaging and crystal violet assays were used to characterize the ability of several cell lines (RKO, H508, HepG2, Huh7, HEK293T (293T), A172, U118-MG, U87, MCF-7, MDA-MB-468, PC3, DLD1 HCT116, and 22RV1) to proliferate in fructose (i.e., the fructolytic ability). Fructose metabolism gene expression was determined by RT-qPCR and western blot for each cell line. A positive selection approach was used to "train" non-fructolytic PC3 cells to utilize fructose for proliferation. RNA-seq was performed on parental and trained PC3 cells to find key transcripts associated with fructolytic ability. A CRISPR-cas9 plasmid containing KHK-specific sgRNA was transfected in 293T cells to generate KHK-/- cells. Lentiviral transduction was used to overexpress empty vector, KHK, or GLUT5 in cells. Metabolic profiling was done with seahorse metabolic flux analysis as well as LC/MS metabolomics. Cell Titer Glo was used to determine cell sensitivity to 2-deoxyglucose in media containing either fructose or glucose. RESULTS: We found that neither the tissue of origin nor expression level of any single gene related to fructose catabolism determine the fructolytic ability. However, cells cultured chronically in fructose can develop fructolytic ability. SLC2A5, encoding the fructose transporter, GLUT5, was specifically upregulated in these cells. Overexpression of GLUT5 in non-fructolytic cells enabled growth in fructose-containing media across cells of different origins. GLUT5 permitted fructose to flux through glycolysis using hexokinase (HK) and not ketohexokinase (KHK). CONCLUSIONS: We show that GLUT5 is a robust and generalizable driver of fructose-dependent cell proliferation. This indicates that fructose uptake is the limiting factor for fructose-mediated cell proliferation. We further demonstrate that cellular proliferation with fructose is independent of KHK.

16.
Biomaterials ; 272: 120765, 2021 05.
Article de Anglais | MEDLINE | ID: mdl-33780686

RÉSUMÉ

Ischemic stroke, and the consequent brain cell death, is a common cause of death and disability worldwide. Current treatments that primarily aim to relieve symptoms are relatively inefficient in achieving brain tissue regeneration and functional recovery, and thus novel therapeutic options are urgently needed. Although cell-based therapies have shown promise for treating the infarcted brain, a recurring challenge is the inadequate retention and engraftment of transplanted cells at the target tissue, thereby limiting the ultimate therapeutic efficacy. Here, we show that transplantation of preassembled three-dimensional (3D) spheroids of mesenchymal stem cells (MSCs) and vascular endothelial cells (ECs) results in significantly improved cell retention and survival compared with conventional mixed-cell suspensions. The transplanted 3D spheroids exhibit notable neuroprotective, proneurogenic, proangiogenic and anti-scarring potential as evidenced by clear extracellular matrix structure formation and paracrine factor expression and secretion; this ultimately results in increased structural and motor function recovery in the brain of an ischemic stroke mouse model. Therefore, transplantation of MSCs and ECs using the 3D cell spheroid configuration not only reduces cell loss during cell harvesting/administration but also enhances the resultant therapeutic benefit, thus providing important proof-of-concept for future clinical translation.


Sujet(s)
Lésions encéphaliques , Encéphalopathie ischémique , Accident vasculaire cérébral ischémique , Transplantation de cellules souches mésenchymateuses , Accident vasculaire cérébral , Animaux , Encéphalopathie ischémique/thérapie , Cellules endothéliales , Souris , Sphéroïdes de cellules , Accident vasculaire cérébral/thérapie
17.
Nanomaterials (Basel) ; 11(2)2021 Feb 07.
Article de Anglais | MEDLINE | ID: mdl-33562217

RÉSUMÉ

A FePt(B, Ag, C) granular film was formed from post-annealed B4C(1.0 nm)/FePt(Ag, C) layers at a substrate temperature of 470 °C for 2 min. The 6 nm thick FePt(B, Ag, C) film demonstrates high perpendicular magnetic anisotropy (Ku = 2.83 × 107 erg/cm3 at 100 K) and out-of-plane coercivity (Hc = 38.0 kOe at 100 K). The Ku and out-of-plane Hc are respectively increased from 38% and 46% between 350 K and 50 K. The sample with a thickness of 8 nm also shows a similar trend for magnetic properties; however, the tiny magnetization kink which may come from rare Fe-B or disordered FePt grains was observed in the easy axis loop. The intrinsic (ΔHint = 12.6 kOe) and extrinsic switching field distribution (ΔHext = 1.62 kOe) were characterized by major and minor loops to correlate the microstructural grains. The coupled FePt grains grown on a single MgTiON grain were observed in a high-resolution transmission electron microstructure (HRTEM) image. This small intergranular exchange coupling was defined by estimating the magnetic cluster size (46.6 nm) from ΔHext and the average grains size (28.2 nm) from TEM images. The temperature dependence of coercivity was fitted to further understand the magnetization reversal process. The lower microstructural parameter was evidenced in the imperfect grain morphology.

18.
Oncogene ; 39(37): 5950-5963, 2020 09.
Article de Anglais | MEDLINE | ID: mdl-32778768

RÉSUMÉ

TMPRSS2 is an important membrane-anchored serine protease involved in human prostate cancer progression and metastasis. A serine protease physiologically often comes together with a cognate inhibitor for execution of proteolytically biologic function; however, TMPRSS2's cognate inhibitor is still elusive. To identify the cognate inhibitor of TMPRSS2, in this study, we applied co-immunoprecipitation and LC/MS/MS analysis and isolated hepatocyte growth factor activator inhibitors (HAIs) to be potential inhibitor candidates for TMPRSS2. Moreover, the recombinant HAI-2 proteins exhibited a better inhibitory effect on TMPRSS2 proteolytic activity than HAI-1, and recombinant HAI-2 proteins had a high affinity to form a complex with TMPRSS2. The immunofluorescence images further showed that TMPRSS2 was co-localized to HAI-2. Both KD1 and KD2 domain of HAI-2 showed comparable inhibitory effects on TMPRSS2 proteolytic activity. In addition, HAI-2 overexpression could suppress the induction effect of TMPRSS2 on pro-HGF activation, extracellular matrix degradation and prostate cancer cell invasion. We further determined that the expression levels of TMPRSS2 were inversely correlated with HAI-2 levels during prostate cancer progression. In orthotopic xenograft animal model, TMPRSS2 overexpression promoted prostate cancer metastasis, and HAI-2 overexpression efficiently blocked TMPRSS2-induced metastasis. In summary, the results together indicate that HAI-2 can function as a cognate inhibitor for TMPRSS2 in human prostate cancer cells and may serve as a potential factor to suppress TMPRSS2-mediated malignancy.


Sujet(s)
Glycoprotéines membranaires/métabolisme , Tumeurs de la prostate/métabolisme , Tumeurs de la prostate/anatomopathologie , Serine endopeptidases/métabolisme , Animaux , Protéines de transport/métabolisme , Lignée cellulaire tumorale , Modèles animaux de maladie humaine , Hétérogreffes , Humains , Mâle , Glycoprotéines membranaires/composition chimique , Invasion tumorale , Tumeurs de la prostate/étiologie , Liaison aux protéines , Motifs et domaines d'intéraction protéique , Cartographie d'interactions entre protéines , Protéines sécrétoires inhibitrices de protéinases/métabolisme , Protéolyse
19.
J Am Chem Soc ; 142(28): 11983-11987, 2020 07 15.
Article de Anglais | MEDLINE | ID: mdl-32588629

RÉSUMÉ

Poly(p-phenylenevinylene)s (PPVs), a staple of the conductive polymer family, consist of alternating alkene and phenyl groups in conjugation. The physical properties of this organic material are intimately linked to the cis/trans configuration of the alkene groups. While many synthetic methods afford PPVs with all-trans stereochemistry, very few deliver the all-cis congeners. We report herein a synthesis of all-cis PPVs with living characteristics via stereoretentive ring-opening metathesis polymerization (ROMP). Exquisite catalyst control allows for the preparation of homopolymers or diblock copolymers with perfect stereoselectivity, narrow dispersities, and predictable average molar masses. All-cis PPVs can then serve as light-responsive polymers through clean photoisomerization of the stilbenoid units.

20.
Am J Otolaryngol ; 40(1): 22-29, 2019.
Article de Anglais | MEDLINE | ID: mdl-30249374

RÉSUMÉ

PURPOSE: The efficacy of postoperative oral corticosteroids on surgical outcomes in chronic rhinosinusitis with nasal polyps (CRSwNP) patients following endoscopic sinus surgery (ESS) remains controversial. This study evaluated the potential benefits of postoperative oral corticosteroids on surgical outcomes in CRSwNP patients and investigated the differential effects on eosinophilic CRSwNP (ECRSwNP) and noneosinophilic CRSwNP (NECRSwNP). MATERIALS AND METHODS: Patients with bilateral CRSwNP who underwent ESS were enrolled and randomized to receive either oral prednisolone (30 mg/day) or placebo for 2 weeks after surgery. Visual analog scale (VAS) and Sino-Nasal Outcome Test 22 (SNOT-22) scores were chosen as the subjective outcomes, evaluated at preoperative baseline and 1, 3, and 6 months postoperatively. Lund-Kennedy Endoscopic Scores (LKESs) were used as the objective outcome, evaluated at preoperative baseline and at 2 weeks and 2, 3, and 6 months postoperatively. RESULTS: In total, 100 patients with bilateral CRSwNP were enrolled, of whom only 82 completed the 6-month follow-up. The subjective outcomes showed no significant difference at each follow-up points. Of the objective outcomes, the corticosteroid group reporting a trend of improvement in LKESs at 6 months postoperatively (p = 0.05). After stratification by tissue eosinophils, only patients with NECRSwNP (<10 eosinophils/HPF) demonstrated a significant improvement in LKESs at 3 months postoperatively (p = 0.03). CONCLUSIONS: Postoperative oral corticosteroids did not provide additional improvements in VAS and SNOT-22 scores; nevertheless, a trend of LKES improvement was noted at 6 months postoperatively. After stratification by tissue eosinophils, this effect was significant only among NECRSwNP patients at 3 months follow-up.


Sujet(s)
Éosinophilie/thérapie , Glucocorticoïdes/administration et posologie , Polypes du nez/thérapie , Prednisolone/administration et posologie , Rhinite/thérapie , Sinusite/thérapie , Administration par voie orale , Adulte , Maladie chronique , Endoscopie , Éosinophilie/complications , Femelle , Humains , Mâle , Adulte d'âge moyen , Polypes du nez/étiologie , Soins postopératoires , Rhinite/étiologie , Sinusite/étiologie , Résultat thérapeutique
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