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1.
J Cell Sci ; 135(5)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34000034

RESUMO

Membrane phase separation to form micron-scale domains of lipids and proteins occurs in artificial membranes; however, a similar large-scale phase separation has not been reported in the plasma membrane of the living cells. We show here that a stable micron-scale protein-depleted region is generated in the plasma membrane of yeast mutants lacking phosphatidylserine at high temperatures. We named this region the 'void zone'. Transmembrane proteins and certain peripheral membrane proteins and phospholipids are excluded from the void zone. The void zone is rich in ergosterol, and requires ergosterol and sphingolipids for its formation. Such properties are also found in the cholesterol-enriched domains of phase-separated artificial membranes, but the void zone is a novel membrane domain that requires energy and various cellular functions for its formation. The formation of the void zone indicates that the plasma membrane in living cells has the potential to undergo phase separation with certain lipid compositions. We also found that void zones were frequently in contact with vacuoles, in which a membrane domain was also formed at the contact site.

2.
Nanoscale ; 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34019046

RESUMO

Correction for 'Discovery of intrinsic two-dimensional antiferromagnets from transition-metal borides' by Shiyao Wang et al., Nanoscale, 2021, 13, 8254-8263, DOI: 10.1039/D1NR01103K.

3.
J Phys Chem Lett ; : 4823-4832, 2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-33999633

RESUMO

An ab initio evolutionary search algorithm was combined with density functional theory (DFT) calculations to predict a series of 2-D BxNy (1 < x/y ≤ 2). Particularly, B5N3 and B7N5 monolayers have sufficiently low formation enthalpy and excellent dynamic stability that make them promising for synthesis in experiments. Electronic structure calculations reveal that B5N3 and B7N5 monolayers possess an indirect band gap of 1.99 eV and a direct band gap of 2.40 eV, respectively. The calculated absorption coefficients for B5N3 and B7N5 monolayers are significantly improved in the low end of the visible region compared with that of 2-D h-BN. Moreover, our calculations reveal that both B5N3 and B7N5 monolayers have high electron carrier mobilities. The narrow band gaps, high carrier mobilities, strong near-ultraviolet absorption, and high synthesis possibility of B5N3 and B7N5 monolayers render them promising new materials for application in novel electronics and environmentally benign solar energy conversion.

4.
Parasitol Res ; 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33830364

RESUMO

In the present study, we provided the first 18S rRNA gene sequence data of two Tripartiella species, Tripartiella macrosoma Basson and Van As, 1987 and Tripartiella obtusa Ergens and Lom, 1970, which were isolated from Tachysurus fulvidraco (Richardson, 1846) and Hemibarbus maculatus Bleeker, 1871 in Chongqing, China, respectively. Morphologically, both species fall within the morphometry range of the original descriptions and are very similar to the original populations in the overall appearance of the adhesive disc. Tripartiella macrosoma can be easily distinguished from the other Tripartiella species by possessing the denticle with a long strip and conspicuously inclined backward blade and a robust and short ray. Tripartiella obtusa is mainly characterized by a broad blade and a relatively long ray. Phylogenetically, T. macrosoma clustered with Trichodinella myakkae (Mueller, 1937) Raabe, 1950 and further with Trichodinella sp., which was sister to a group that includes four populations of Trichodinella epizootica (Raabe, 1950) Srámek-Husek, 1953; finally, they formed a small clade with T. obtusa. This result suggested that T. macrosoma had a closer relationship with Trichodinella spp. than with T. obtusa and T. obtusa diverged earlier than T. macrosoma and Trichodinella spp. By combining morphological and molecular data, the polyphyletic characteristics of Tripartiella and Trichodinella were further analyzed, and the results revealed that the validity of the genus Tripartiella is doubtful.

5.
Nanoscale ; 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33885686

RESUMO

Intrinsic two-dimensional (2D) magnets are promising materials for developing advanced spintronic devices. A few have already been synthesized from the exfoliation of van der Waals magnetic materials. In this work, by using ab initio calculations and Monte Carlo simulation, a series of 2D MBs (M = Cr, Mn or Fe; B = boron) are predicted possessing robust magnetism, sizeable magnetic anisotropy energy, and excellent structural stability. These 2D MBs can be respectively synthesized from non-van der Waals compounds with low separation energies such as Cr2AlB2, Mn2AlB2, and Fe2AlB2. 2D CrB is a ferromagnetic (FM) metal with a weak in-plane magnetic anisotropy energy of 23.6 µeV per atom. Metallic 2D MnB and FeB are Ising antiferromagnets with an out-of-plane magnetic easy axis and robust magnetic anisotropy energies up to 222.7 and 482.2 µeV per atom, respectively. By using Monte Carlo simulation, the critical temperatures of 2D CrB, MnB, and FeB were calculated to be 440 K, 300 K, and 320 K, respectively. Our study found that the super-exchange interaction plays the dominant role in determining the long-range magnetic ordering of 2D MBs. Moreover, most functionalized 2D MBTs (T = O, OH or F) are predicted to have AFM ground states. Alternating transition metals or functional groups can significantly modulate the magnetic ground state and critical temperature of 2D MBTs. This study suggests that the 2D MBs and MBTs are promising metallic 2D magnets for spintronic applications.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33808565

RESUMO

This research focused on the psychological impact of an epidemic. We conducted a cross-sectional survey and two empirical experiments to examine how an epidemic would influence unethical behaviors and how the effect differs in people of different subjective socioeconomic statuses. These studies consistently demonstrated that subjective socioeconomic status moderates the relationship between an epidemic and unethical behaviors. Specifically, the perceived severity of an epidemic positively predicts the unethical behaviors of people with a high socioeconomic status, but it does not predict the unethical behaviors of people with a low socioeconomic status. These findings elucidate the effects of epidemics and bring theoretical and practical implications.


Assuntos
Epidemias , Classe Social , Estudos Transversais , Humanos
7.
Pers Soc Psychol Bull ; : 146167220974496, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33272111

RESUMO

We conducted six studies to test our hypotheses that ostracism disrupts self-continuity and that self-affirmation counters ostracism's negative influence on self-continuity. Participants who experienced more ostracism in their daily lives (Study 1), imagined being ostracized (Studies 2 and 5), recalled a past ostracism experience (Studies 3 and 6), and were ostracized in a ball-tossing game (Study 4) reported lower levels of self-continuity than their counterparts. Moreover, neither violations of expectation nor negativity of the experience was sufficient in decreasing self-continuity (Study 5). Finally, self-affirmation weakened the negative effect of ostracism on self-continuity (Study 6). Taken together, our findings provide converging causal evidence for our hypotheses and provide novel insights for the literature on how daily interpersonal interactions influence individuals' sense of an enduring self. In addition, the moderation of self-affirmation reported in our research indicates an effective approach to diminishing the negative influence of ostracism.

8.
J Pediatr Orthop B ; 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33165213

RESUMO

Our study aimed to compare the clinical and radiographic outcomes of transitional distal tibia fractures treated with K-wire fixation versus screw fixation after open reduction. A retrospective study was performed on all displaced transitional distal tibia fractures that underwent operative fixation. Following open reduction, surgical fixation was performed using either percutaneously inserted 2.0 mm K-wires, or 4.0 mm partially-threaded cannulated cancellous screws. Clinical and radiographic outcomes between the two groups were assessed using the modified Weber score. Other outcome measures assessed were surgical time, casting duration, follow-up duration and duration before return-to-sports. We recruited 49 patients with transitional distal tibia fractures requiring open reduction and surgical fixation. There were 18 patients in the K-wiring group (KWG), and 31 patients in the screw fixation group (SFG). All patients in both groups had excellent clinical and radiographic outcome based on the modified Weber's scoring, full radiological healing, and no residual displacement upon final follow up. The KWG had significantly shorter surgical time (41.0 min versus 75.1 min, P < 0.0001) and shorter follow-up duration needed before discharge (5.4 months versus 8.7 months, P = 0.024). However, they required a longer post-operative casting duration (7.3 weeks versus 5.3 weeks, P = 0.006). No significant difference was found for the duration before return to sports between both groups. Complications were few in this study group. Superficial pin site infection was noted in one patient in the KWG, and valgus deformity of the ankle was noted in one patient in the SFG. In our study, surgical treatment of transitional distal tibia fractures demonstrated equally excellent outcomes when treated by open reduction with either K-wire or cannulated screw fixation. Level of evidence: III.

9.
BMJ Open ; 10(11): e036809, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177132

RESUMO

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease characterised by a fibrotic histological pattern found in usual interstitial pneumonia. Its causes, pathogenesis, clinical phenotype and molecular mechanisms are poorly defined. Large-scale, multicentre studies are warranted to better understand IPF as a disease in China, its associated risk factors, clinical characteristics, diagnosis, disease progression and treatment. METHODS AND ANALYSIS: The Idiopathic Pulmonary Fibrosis Registry China Study (PORTRAY) is a prospective, multicentre registry study of patients with IPF in China. Eight hundred patients will be enrolled over a 36-month period and followed for at least 3 years to generate a comprehensive database on baseline characteristics and various follow-up parameters including patient-reported outcomes. Biological specimens will also be collected from patients to develop a library of blood, bronchoalveolar lavage fluid and lung biopsy samples, to support future research. As of 15 December 2019, 204 patients from 19 large medical centres with relatively high IPF diagnosis and treatment rates had been enrolled. Patient characteristics will be presented using descriptive statistics. The Kaplan-Meier method will be used for survival analyses. Repeated measures will be used to compare longitudinal changes in lung function, imaging and laboratory tests. Results following analysis have been projected to be available by July 2025. ETHICS AND DISSEMINATION: The study protocol was reviewed and approved by the Institutional Review Board from all the study sites currently recruiting patients. Study results will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03666234.

10.
Sensors (Basel) ; 20(20)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33081178

RESUMO

Sediment and flow depth monitoring in sewers is important for informing flow models and for predicting and mitigating against sewer blockage formation and surcharge. In this study, a novel sensor based on conductance measurement has been developed and tested under a laboratory environment and validated by a finite-element model. The relative conductance is measured between pairs of adjacent electrodes to provide a conductance profile along the sensor length. A piecewise linear relationship between conductance and electrode length was derived and the interface positions between sediment, water, and air can be determined from the profile. The results demonstrated that the root mean square error of the model and the measured interface level are within 1.4% and 2.6% of sensor's measurement range. An error distribution of interface height shows that all anticipated errors are within the resolution of the electrode length increments. Furthermore, it was found that the conductivity of the measured medium is proportional to the gradient of the linear relationship of conductance and electrode length. It could therefore prove a valuable new tool for the accurate quantification of sediment and flow levels in sewer conduits, coastal environments, drainage systems for transport networks, and other industrial or academic applications.

11.
BMC Pulm Med ; 20(1): 183, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600302

RESUMO

BACKGROUND: Identification of pathologic features is helpful for the management of nonresolving acute respiratory distress syndrome (ARDS). Transbronchial lung cryobiopsy (TBLC) is a novel biopsy technique that may have comparable utility to surgical biopsy. The aim of this study was to assess the value of TBLC in patients with nonresolving ARDS. METHODS: All patients with nonresolving ARDS who underwent TBLC from January 2019 to August 2019 in a tertiary medical ICU were included. In addition, a literature search of TBLC for ARDS was performed by searching PubMed, EMBASE, ATS/ERS/APSR meeting abstracts, ClinicalTrials.gov , and Google Scholar. Data on complications, histologic diagnosis, management changes, and outcomes were analysed. RESULTS: Five patients (three women and two men) underwent TBLC. None of the patients developed pneumothorax, although two patients developed massive bleeding, which was controlled by continuous occlusion using bronchial blockers. There were no procedure-related deaths. Diffuse alveolar damage (DAD) and alternative histologic patterns were found in two and three patients, respectively, resulting in management changes in all cases. The literature search yielded four studies, which together with the present study comprised data from 25 cases in which TBLC was used in nonresolving ARDS. The summary diagnostic yield was 92% (23/25). Only 44% (11/25) of cases were proven to be DAD. TBLC contributed to management changes in 80% of patients (20/25). Procedure-related complications consisted of pneumothorax (16%, 4/25), significant bleeding (12%, 3/25), and persistent air leaks (8%, 2/25). There were no procedure-related deaths. The follow-up survival rate was 61.9% (13/21). CONCLUSIONS: The complications of TBLC in selected patients with nonresolving ARDS may be acceptable. The procedure may have a high diagnostic yield and can lead to a re-evaluation of the diagnosis as well as changes in patient management. Further investigations with larger sample sizes are required.

12.
Phys Chem Chem Phys ; 22(20): 11731-11739, 2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32409802

RESUMO

Two-dimensional (2-D) antiferromagnetic (AFM) materials have shown promise over their ferromagnetic (FM) counterparts for developing advanced spintronic devices; however, they have been rarely found with high Néel temperatures to date. Here, by employing first-principles calculations and Monte Carlo simulations, we demonstrate that the family of 2-D iron oxyhalides monolayers, FeOX (X = F, Cl, Br, I), are magnetic Mott insulators with their AFM ground state possessing relatively high Néel temperatures. The structural stabilities of the FeOX monolayers are proved using a set of phonon, molecular dynamics, and elastic constant calculations. The calculated Néel temperature of the FeOCl monolayer is close to that of FeOCl bulk because of the weak van der Waals interaction between the layers. More importantly, the predicted Néel temperatures of FeOX (X = F, Cl, Br, I) monolayers can be increased by biaxial compression strain. The Néel temperature of the strained FeOF and FeOI monolayers can approach 200 K, which suggests that they can be robust antiferromagnets with relatively high Néel temperatures compared with other available 2-D magnets. Our calculations show that both the in-plane and the inter-plane magnetic interactions affect the AFM coupling between Fe atoms in FeOX monolayers. The easy axis of the 2-D FeOX is found to be along the in-plane direction. The FeOX monolayers may provide an excellent platform for building novel spintronic devices at the nanoscale.

13.
J Immunol Res ; 2020: 4092472, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32455139

RESUMO

Background: The drug resistance and the immune suppression in the tumor microenvironment are important factors affecting tumor progression. Reversing drug resistance and changing tumor suppression microenvironment are ideal ways to inhibit tumor progression. Objective: The aim of the study is to verify antitumor immune response of probiotics in patients with colorectal carcinoma and to explore its mechanism. Methods: To detect the tumor samples of 122 patients with colorectal carcinoma after surgery, analyze the effect of probiotics on enhancing tumor-infiltrating CD8+T cells to inhibit colorectal carcinoma, and further verify the mechanism of probiotics on enhancing the antitumor immune response of CD8+T cells through animal experiments. Results: The results of immunohistochemistry showed that the proportion of CD8+T cells in the patients treated with probiotics before surgery was increased significantly than that in other patients (P = 0.033). The results of flow cytometry also showed that the proportion of CD8+T cells in the probiotics group was higher than that in the nonprobiotics group (P = 0.029). Kaplan-Meier survival estimates also showed that the CD8+T cells, TNM stage, pathology grade, lymphatic metastasis, and probiotic treatment were significantly associated with the progression-free survival (PFS) (χ 2 = 9.684, P = 0.002 for CD8+T cells; χ 2 = 5.878, P = 0.015 for TNM stage; χ 2 = 7.398, P = 0.004 for pathology grade; χ 2 = 8.847, P = 0.003 for Lymphatic metastasis; and χ 2 = 4.622, P = 0.032 for the group (group A was treated with probiotics before surgery; group B was not treated with probiotics)). The experimental results in mice showed that probiotics could inhibit tumor growth and increase the proportion of CD8+T cells in mice; the difference was statistically significant (P = 0.037). It was also found that probiotic feeding could upregulate the expression of T-cell immunoglobulin mucin receptor 1(TIM-1) in CD8+T cells of mice and also found that probiotic feeding could downregulate the expression of programmed cell death protein 1 (PD-1) in CD8+T cells of mice, compared with the nonfeeding group; the difference was statistically significant (P = 0.045 for TIM-1 and P = 0.02 for PD-1, respectively). In order to further understand the functional status of CD8+T cells, we analyzed interferon-gamma (IFN-γ)+ T cells and tumor necrosis factor-α (TNF-α)+CD8+T cells by flow cytometry. The results showed that the proportion of IFN-γ + T cells and TNF-α +CD8+T cells significantly increased after probiotic treatment, compared with the nonprobiotic treatment group; the difference was statistically significant (P = 0.040 for IFN-γ + T cells and P = 0.014 for TNF-α +CD8+T, respectively). Conclusions: Probiotics can enhance the antitumor immune response of CD8+T cells. It can play a synergistic antitumor role. On the one hand, its mechanism is through regulating intestinal flora, and on the other hand, through regulating the antitumor immune function of CD8+T cells.

14.
Medicine (Baltimore) ; 99(14): e19420, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32243362

RESUMO

The aim of this study is to evaluate the predictive value of carbohydrate antigen125 (CA125) and carcino embryonic antigen (CEA) expression and its guiding role of choosing chemotherapy regimen in post-operation patients with colorectal carcinoma.The clinical data of all patients, including laboratory data and pathological data, were collected from the electronic medical records. Kaplan-Meier Log rank test, COX regression model and subgroup analyses were employed to assess the correlation between the expression of CA125 and CEA in patients with colorectal carcinoma and the survival, and the effect on chemotherapy efficacy.Kaplan-Meier showed that CA125 expression is negatively related to the progression-free survival (PFS) of the post-operative patients, Median PFS was 1140 days in the patients with high expression, and Median PFS was 1387 days in the patients with low expression (χ = 4.715, P = .030); CEA expression is also negatively associated with the PFS of the post-operative patients, Median PFS was 1197 days in the patients with high expression, and Median PFS was 1424 days in the patients with low expression (χ = 4.992, P = .025). Subgroup analysis also showed that the patients with normal CA125 and CEA had better prognosis, median PFS was 1505 days, and the patients with CA125 and (or) CEA high expression had poor prognosis and median PFS was 1162 days (χ = 13.346, P = .001), and found that there was no statistical difference in patients with oxaliplatin plus capecitabine (XELOX) and oxaliplatin, 5-fluorouracil and Calcium folinate (FOLFOX) chemotherapy in patients with CA125 and CEA low expression. However, in these patients with CA125 or (and) CEA high expression, the median PFS of patients treated with XELOX was 1082 days, and the median PFS of patients treated with FOLFOX chemotherapy was 1335 (χ = 4.547, P = .033).Expression of CA125 and CEA associated with the survival of patients, and have some guiding significance for chemotherapy in patients with colorectal cancer after operation; Compared with XELOX, FOLFOX chemotherapy is more effective for CA125 or (and) CEA high expression patients with colorectal carcinoma.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno Ca-125/sangue , Antígeno Carcinoembrionário/sangue , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Adulto , Idoso , Biomarcadores Tumorais , Capecitabina , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Feminino , Fluoruracila , Humanos , Estimativa de Kaplan-Meier , Leucovorina , Masculino , Pessoa de Meia-Idade , Compostos Organoplatínicos , Oxaloacetatos , Prognóstico
15.
Am J Transl Res ; 12(3): 940-949, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32269725

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a devastating disease, which is characterized by the progressive deterioration in lung function. In the pathogenesis of IPF, insulin-like growth factor-1 (IGF-1) has been found to be heavily involved. Metformin, a commonly used oral antidiabetic agent, is known to inhibit IGF-1 by the reversal of hyperinsulinemia. In this study, we evaluated the effects of metformin in pulmonary fibrosis in C57/BL6J mice, and further understand the role of IGF-1 signaling pathway involving in this process. Pulmonary fibrosis was induced experimentally in these mice by the intratracheal injection of bleomycin (BLM). Metformin was given orally the day before or 14 days after bleomycin injection, while pirfenidone was used as the positive control. Our study showed that intratracheal injection of bleomycin induced pulmonary fibrosis in mice, with observed elevation in collagen, fibronectin and α-SMA level, characterized by the enhanced IGF-1 and PI3K expression. Metformin was able to inhibit these effects significantly, and its antifibrotic effect had no marked difference with pirfenidone. Our results show that metformin attenuates bleomycin-induced pulmonary fibrosis via IGF-1 pathway.

16.
Small ; 16(16): e2000596, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32162833

RESUMO

Research on transition metal dichalcogenides (TMDs) has been accelerated by the development of large-scale synthesis based on chemical vapor deposition (CVD) growth. However, in most cases, CVD-grown TMDs are composed of randomly oriented grains, and thus contain many distorted grain boundaries (GBs), which seriously degrade their electrical and photoelectrical properties. Here, the epitaxial growth of highly aligned MoS2 grains is reported on a twofold symmetry a-plane sapphire substrate. The obtained MoS2 grains have an unusual rectangle shape with perfect orientation alignment along the [1-100] crystallographic direction of a-plane sapphire. It is found that the growth temperature plays a key role in its orientation alignment and morphology evolution, and high temperature is beneficial to the initial MoS2 seeds rotate to the favorable orientation configurations. In addition, the photoluminescence quenching of the well-aligned MoS2 grains indicates a strong MoS2 -substrate interaction which induces the anisotropic growth of MoS2 , and thus brings the formation of rectangle shape grains. Moreover, the well-aligned MoS2 grains splice together without GB formation, and thus that has negligible effect on its electrical transport properties. The progress achieved in this work could promote the controlled synthesis of large-area TMDs single crystal film and the scalable fabrication of high-performance electronic devices.

17.
Lab Chip ; 20(6): 1058-1065, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32073018

RESUMO

We report a novel lensless on-chip microscopy platform based on near-field blind ptychographic modulation. In this platform, we place a thin diffuser in between the object and the image sensor for light wave modulation. By blindly scanning the unknown diffuser to different x-y positions, we acquire a sequence of modulated intensity images for quantitative object recovery. Different from previous ptychographic implementations, we employ a unit magnification configuration with a Fresnel number of ∼50 000, which is orders of magnitude higher than those of previous ptychographic setups. The unit magnification configuration allows us to have the entire sensor area, 6.4 mm by 4.6 mm, as the imaging field of view. The ultra-high Fresnel number enables us to directly recover the positional shift of the diffuser in the phase retrieval process, addressing the positioning accuracy issue plaguing regular ptychographic experiments. In our implementation, we use a low-cost, DIY scanning stage to perform blind diffuser modulation. Precise mechanical scanning that is critical in conventional ptychography experiments is no longer needed in our setup. We further employ an up-sampling phase retrieval scheme to bypass the resolution limit set by the imager pixel size and demonstrate a half-pitch resolution of 0.78 µm. We validate the imaging performance via in vitro cell cultures, transparent and stained tissue sections, and a thick biological sample. We show that the recovered quantitative phase map can be used to perform effective cell segmentation of a dense yeast culture. We also demonstrate 3D digital refocusing of the thick biological sample based on the recovered wavefront. The reported platform provides a cost-effective and turnkey solution for large field-of-view, high-resolution, and quantitative on-chip microscopy. It is adaptable for a wide range of point-of-care-, global-health-, and telemedicine-related applications.

18.
Chin Med J (Engl) ; (6): 679-686, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32068606

RESUMO

BACKGROUND: Fibroblast-like synoviocytes (FLSs), resident mesenchymal cells of synovial joints, play an important role in the pathogenesis of rheumatoid arthritis (RA). Dickkopf-1 (DKK-1) has been proposed to be a master regulator of bone remodeling in inflammatory arthritis. Here, potential impairation on the activity of FLSs derived from RA to small interfering RNAs (siRNAs) targeting DKK-1 was investigated. METHODS: siRNAs targeting DKK-1 were transfected into FLSs of patients with RA. Interleukin (IL)-1ß, IL-6, IL-8, matrix metalloproteinase (MMP) 2, MMP3, MMP9, transforming growth factor (TGF)-ß1, TGF-ß2 and monocyte chemoattractant protein (MCP)-1 levels in the cell culture supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Invasion assay and H incorporation assay were utilized to investigate the effects of siRNAs targeting DKK-1 on FLSs invasion and cell proliferation, respectively. Western blotting was performed to analyze the expression of nuclear factor (NF)-κB, interleukin-1 receptor-associated kinase (IRAK)1, extracellular regulated protein kinases (ERK)1, Jun N-terminal kinase (JNK) and ß-catenin in FLSs. RESULTS: DKK-1 targeting siRNAs inhibited the expression of DKK-1 in FLSs (P < 0.01). siRNAs induced a significant reduction of the levels of IL-6, IL-8, MMP2, MMP3 and MMP9 in FLSs compared to the control group (P < 0.05). DKK-1 targeting siRNAs inhibited the proliferation and invasion of FLSs (P < 0.05). Important molecules of pro-inflammatory signaling in FLSs, including IRAK1 and ERK1, were decreased by the inhibition of DKK-1 in FLSs. In contrast, ß-catenin, a pivotal downstream molecule of the Wnt signaling pathway was increased. CONCLUSIONS: By inhibiting DKK-1, we were able to inhibit the proliferation, invasion and pro-inflammatory cytokine secretion of FLSs derived from RA, which was mediated by the ERK or the IRAK-1 signaling pathway. These data indicate the application of DKK-1 silencing could be a potential therapeutic approach to RA.

19.
J Mol Cell Biol ; 12(7): 515-529, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31900494

RESUMO

After leaving the testis, mammalian sperm undergo a sequential maturation process in the epididymis followed by capacitation during their movement through the female reproductive tract. These phenotypic changes are associated with modification of protein phosphorylation and membrane remodeling, which is requisite for sperm to acquire forward motility and induce fertilization. However, the molecular mechanisms underlying sperm maturation and capacitation are still not fully understood. Herein, we show that PPP3R2, a testis-specific regulatory subunit of protein phosphatase 3 (an isoform of calcineurin in the testis), is essential for sperm maturation and capacitation. Knockout of Ppp3r2 in mice leads to male sterility due to sperm motility impairment and morphological defects. One very noteworthy change includes increases in sperm membrane stiffness. Moreover, PPP3R2 regulates sperm maturation and capacitation via (i) modulation of membrane diffusion barrier function at the annulus and (ii) facilitation of cholesterol efflux during sperm capacitation. Taken together, PPP3R2 plays a critical role in modulating cholesterol efflux and mediating the dynamic control of membrane remodeling during sperm maturation and capacitation.

20.
Mod Rheumatol ; : 1-11, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31859545

RESUMO

Background: Primary Sjögren's syndrome (SS) is a lymphoproliferative disease with a chronic autoimmune disorder characterized by mononuclear cell (MNC) infiltration of notably the lacrimal and salivary glands. As mesenchymal stem cells (MSCs) regulate series of immunological responses partially by regulating proportion of CD4+ T cells and inducing an immunosuppressive local milieu, umbilical cord MSCs (UC-MSCs) are being considered as a novel source for cell-based therapies against primary SS. This study aimed to investigate the feasibility of UC-MSCs in treatment of SS and to explore the possible mechanism(s) with the special emphasis on regulatory T cells (Tregs).Methods: Potent immunosuppressive effects of human UC-MSCs on SS were explored in vivo and in vitro. To study the effects of human UC-MSCs on the development and progression of SS, human UC-MSCs were administered before disease onset (preventive protocol) and after disease occurrence (therapeutic protocol) in non-obese diabetic (NOD) mice. In human study, the effect of human UC-MSCs on T cells from SS patients was studied.Results: In both protocols, the histopathology of submandibular and sublingual salivary glands showed decreased inflammatory infiltrates. In vitro, human UC-MSCs exhibited potent suppressive effects on responses of MNCs in NOD mice and T cells in SS patients. Such inhibitory effects were coupled with decreased production of proinflammtory cytokines interferon-γ, interleukin (IL)-6, tumor necrosis factor-α and increased production of IL-10 (n = 10, p < .01). The frequency of CD4+Foxp3+T cells in the spleen of NOD recipients was elevated (n = 6, p < .05).Conclusion: Human UC-MSCs are capable of inducing CD4+Foxp3+ T cells in both NOD mice and human in vitro. Human UC-MSCs effectively interfere with the autoimmune attack in the course of SS by inducing an in vivo state of T cell unresponsiveness and the upregulation of Tregs.

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