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1.
Biosci Rep ; 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31904090

RESUMO

Cilia and flagella are critical organelles with conserved internal structures and diverse developmental and physiological processes according to cell type. Although the core components of structures are shared with thousands of associated proteins involved in cilia or flagella formation, we hypothesized that some unknown proteins, such as outer dense fiber 2 (Odf2/Cenexin) perform distinct functions in these organells. In this study, we identified several uncharacterized proteins through mass spectrometry interactome analysis of Odf2/Cenexin proteins. We further examined the expression patterns and functions of a protein named cilia and flagella associated protein 58 (Cfap58) in cultured astrocytes and sperm flagella. The results of a combination of biochemical analyses and drug administration studies reveal that Cfap58 is a testis-enrichment protein that exhibits similar localization to Odf2/Cenexin proteins and is required for the elongation of the primary cilium and sperm midpiece via modulation of the Notch signaling pathway. However, the cell cycle related functions and localization of Odf2/Cenexin in the mother centriole were not altered in Cfap58 knockdown cells. These findings indicate that Cfap58 may be partially recruited by Odf2/Cenexin proteins and is indispensable for the cilia and flagellar assembly. These data provide us with a better understanding of ciliogenesis and flagellar elongation and may aid in identifying new targets for diseases caused by Notch-mediated ciliopathies and flagellar abnormalities.

2.
J Appl Gerontol ; : 733464819898316, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31904275

RESUMO

Background: Previous research has established the influence of acculturation and family cohesion on Chinese Americans' mental health and health behavior; however, the influence of acculturation and family cohesion on self-rated health among this population has not been examined. The purpose of this study is to examine the association between family cohesion, acculturation, and self-rated health among older Chinese Americans. Method: Data came from structured interviews with 385 Chinese Americans aged 55 and older living in a large metropolitan area in Southwest. We used logistic regression to examine the association between acculturation, family cohesion, and self-rated health. Results: Acculturation was positively associated with self-rated health only among those with medium (odds ratio [OR] = 2.27, p < .05) and high (OR = 1.93, p < .05) family cohesion, but not among those with low family cohesion. Discussion: Findings highlight the significance of involving family members and strengthening family support in the acculturation and supportive services provided to older Chinese Americans.

3.
Org Biomol Chem ; 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31894805

RESUMO

A metal-free K2S2O8-HFIP synergistically promoted double Friedel-Crafts alkylation between a glycine derivative and N-substituted aniline was developed to efficiently synthesize diarylmethane derivatives with high para-selectivity. The reaction proceeded smoothly in the absence of any metal and ligand, and exhibited a good tolerance of functional groups.

4.
PLoS One ; 14(12): e0226116, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31805143

RESUMO

The timing of both flowering and maturation determine crop adaptability and productivity. Soybean (Glycine max) is cultivated across a wide range of latitudes. The molecular-genetic mechanisms for flowering in soybean have been determined for photoperiodic responses to long days (LDs), but remain only partially determined for the delay of flowering under short-day conditions, an adaptive trait of cultivars grown in lower latitudes. Here, we characterized the late-flowering (LF) habit introduced from the Thai cultivar K3 into a photoperiod-insensitive genetic background under different photo-thermal conditions, and we analyzed the genetic basis using quantitative trait locus (QTL) mapping. The LF habit resulted from a basic difference in the floral induction activity and from the suppression of flowering, which was caused by red light-enriched LD lengths and higher temperatures, during which FLOWERING LOCUS T (FT) orthologs, FT2a and FT5a, were strongly down-regulated. QTL mapping using gene-specific markers for flowering genes E2, FT2a and FT5a and 829 single nucleotide polymorphisms obtained from restriction-site associated DNA sequencing detected three QTLs controlling the LF habit. Of these, a QTL harboring FT2a exhibited large and stable effects under all the conditions tested. A resequencing analysis detected a nonsynonymous substitution in exon 4 of FT2a from K3, which converted the glycine conserved in FT-like proteins to the aspartic acid conserved in TERMINAL FLOWER 1-like proteins (floral repressors), suggesting a functional depression in the FT2a protein from K3. The effects of the remaining two QTLs, likely corresponding to E2 and FT5a, were environment dependent. Thus, the LF habit from K3 may be caused by the functional depression of FT2a and the down-regulation of two FT genes by red light-enriched LD conditions and high temperatures.

5.
BMC Cardiovasc Disord ; 19(1): 287, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31830920

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) with right ventricle metastasis without inferior vena cava and right atrium involvement is very rare and the prognosis of HCC with RV metastasis is generally poor. The mass in the cardiac chamber may lead to lethal instability of hemodynamics, however, the initial symptom is probably non-specific, which means that diagnosis timely becomes even harder. CASE PRESENTATION: We present a 63-year-old male with isolated metastasis of HCC in the right ventricle which caused inflow obstruction. Moreover, we reviewed a series of studies of isolated metastasis of hepatocellular carcinoma between 1980 and 2018, and summarized the relative outcomes. CONCLUSIONS: Isolated metastasis of hepatocellular carcinoma in the right ventricle is extraordinarily rare. It may damage cardiac structure and broke hemodynamic balance. Multimodality imaging plays an important in accurate pre-operation assessment. Nowadays, palliative treatments could relieve fatal symptoms to some degree, however, standard treatment has not been well established.

6.
Reproduction ; 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31786538

RESUMO

Small extracellular vesicles (sEVs) are important mediators of cell-to-cell communication involved in successful establishment of a pregnancy. Human decidual stromal cells play a key role in regulating trophoblast invasion. Nevertheless, the regulatory functions of decidual stromal cells-derived sEVs in human trophoblast cells are still unclear. In this study, primary human decidual stromal cells were isolated and immortalized human endometrial stromal cell line (HESCs) were decidualised into human decidual stromal cells (HDSC) using hormonal cocktail containing Medroxy progesterone 17-acetate (MPA), estrogen and cAMP analog. HDSC-sEVs were isolated from both primary human decidual stromal cells and immortal HDSCs respectively, and identified by transmission electron microscopy and western blotting. EVs up-taken assay indicated that HDSC-sEVs could be up-taken by trophoblast cells. HDSC-sEVs could increase the invasiveness and the expression level of N-cadherin of trophoblast cells with elevated phosphorylation of SMAD2 and SMAD3 in the cells. Silencing of N-cadherin could block cell invasion induced by HDSC-sEVs, while knockdown of SMAD2 and SMAD3 could inhibit the up-regulation of N-cadherin in trophoblast cells. Taken together, our results suggested a regulatory effect of HDSC-sEVs in the invasion of trophoblast cells, and HDSC-sEVs may be important mediators of trophoblasts during embryo implantation and placentation.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31794839

RESUMO

PURPOSE: To compare long-term survival outcomes and sequelae between children and adult nasopharyngeal carcinoma (NPC) in the era of intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS: Data on 285 NPC patients aged ≤ 18 years old at diagnosis and treated with IMRT between January 2004 and November 2016 were retrospectively reviewed. Propensity score matching method was adopted to screen matched adult NPC patients at a ratio of 1:3. Survival outcomes and treatment-related toxicities between children and adult groups were compared. RESULTS: In total, 159 children and 477 adult NPC patients were included in this study. The 5-year overall survival (OS), distant metastasis-free survival (DMFS), locoregional relapse-free survival (LRRFS), and disease-free survival (DFS) between children and adult were 89.2% vs 83.6% (P = 0.144), 88.7% vs 83.5% (P = 0.124), 96.4% vs 89.1% (P = 0.013), and 86.5% vs 77.3% (P = 0.021), respectively. Subgroup analyses revealed that the young age was an independent prognostic factor of OS, DMFS and LRRFS in advanced N stage (N2-3) group, and DFS in advanced T stage (T3-4) group, N2-3 and stage III-IVA groups. The most common sequela was ototoxicity (68.9%) in children patients and xerostomia (70.8%) in adult patients. Adult survivors had a significantly higher incidence of grade 3-4 late toxicities in xerostomia (17.6% vs. 8.9%, P = 0.004), skin dystrophy (9.3% vs. 3.7%, P = 0.022), neck fibrosis (8.3% vs. 4.4%, P < 0.001) and radiation encephalopathy (0.8% vs. 0, P = 0.006). Children survivors were more likely to develop grade 3-4 growth retardation and endocrine insufficiency (3.0% vs. 0.3%, P = 0.014). CONCLUSIONS: Children NPC patients achieved significantly better survival outcomes but less late toxicities than adult patients. However, we should pay great attention to growth problems of children survivors.

8.
Onco Targets Ther ; 12: 9319-9327, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31807012

RESUMO

Objective: To explore the regulation of long-chain noncoding BANCR on cell invasion and migration of esophageal squamous carcinoma cells and related mechanisms. Method: The mRNA expression of BANCR in esophageal squamous carcinoma cells and esophageal squamous cells was detected by quantitative PCR . The relationship between the expression of BANCR and the survival rate of patients with esophageal squamous cell carcinoma (ESCC) was analyzed by Kaplan-Meier method. The BANCR pair was detected by Transwell invasion and scratch test. In ESCC cell lines, the cells had invasion and migration ability; Western blot was applied to detect the expression of proteins involved in the Wnt/ß-catenin signaling pathway. Results: BANCR revealed relatively high expression in esophageal squamous carcinoma cells, and the higher the expression of BANCR was, the lower the survival rate of patients with ESCC was. Inhibition of BANCR expression could effectively reduce the invasion and migration ability of esophageal squamous cell carcinoma. After silencing BANCR, the expression of wnt3a, survivin, ß-catenin and c-myc protein was downregulated compared with the negative control group (p<0.05). Conclusion: Long-chain noncoding BANCR was highly expressed in patients with ESCC and was negatively correlated with patients' survival time. It was of the capability to modulate the cell migration and invasion of ESCC cells through inducing Wnt/ß-catenin signaling pathway.

9.
Sci Rep ; 9(1): 19931, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31882717

RESUMO

In the present work, the biomass derived carbon decorated with humic acid (HC), was synthesized through impregnation method for the adsorption of phenol from water environment. Humic acids contain more oxygen-containing functional groups and hydrogen bonds, which promotes the binding between HC and phenol molecules. The results indicated that the adsorption performance of HC to phenol was better than that of commercial activated carbon. Moreover, in addition to physical absorption, the chemical reaction between carboxylic groups on the carbon surface and hydroxyl in phenol also played an important role during the process. The adsorption behavior of HC was described by equilibrium and kinetics parameters. Pseudo-second order model can describe the adsorption process well. Langmuir model was more suitable for the equilibrium adsorption data fitting, indicating that the adsorption mechanism of phenol on carbon surface tends to be monolayer adsorption. Considering practical application, UV254, chemical oxygen demand (COD) and ammonia from raw wastewater were selected as target contaminants and the corresponding adsorption experiments were carried out. The results displayed that HC exhibited excellent adsorption performance, especially for UV254, indicating that as-prepared carbon material had potential application for the control of certain organic pollutants in actual wastewater.

10.
Opt Express ; 27(23): 33757-33767, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31878437

RESUMO

A new method to control heat flux, called thermal surface transformation (TST), is introduced from transformation thermodynamics. Compared with transformation thermodynamics, TST has many advantage. First, there is no mathematical calculation during the whole process in TST (novel thermal devices can be designed graphically in a surface-to-surface way). Second, all thermal devices of various functions, shapes and sizes designed by TST only require one homogenous anisotropic thermal medium, i.e., thermal-null medium (TNM). With the help of the effective medium theory, TNM can be realized by layered copper and expanded polystyrene, whose performance on controlling heat flux by TST is verified by numerical simulations. Many examples are given, including thermal imaging devices, thermal unidirectional cloak, concentrator, rotator and thermal focusing devices.

11.
Biosci Rep ; 39(11)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31693733

RESUMO

The aim of the present study was to explore the role of long non-coding RNA (lncRNA) non-coding repressor of NFAT (NRON) in the atrial fibrosis and to explore whether its underlying mechanism was associated with macrophage polarization. Enzyme-linked immunosorbent assay (ELISA) analysis of pro-inflammatory cytokines revealed that NRON overexpression suppressed, whereas NRON silencing facilitated the angiotensin II (Ang II)-induced inflammatory response in primary cultured atrial myocytes. The chromatin immunoprecipitation (ChIP) results showed that nuclear factor of activated T cell 3 (NFATc3) was recruited to the promoter region of interleukin (IL) 12 (IL-12) in atrial myocytes. Further data showed that NRON overexpression suppressed, whereas NRON silencing further promoted the Ang II-induced NFATc3 nuclear transport and IL-12 expression in atrial myocytes. Moreover, RAW264.7 macrophages were incubated with the conditioned medium from the Ang II-treated atrial myocytes transfected with NRON and IL-12 overexpression vectors. IL-12 overexpression abrogated the NRON overexpression-mediated inhibition of RAW264.7 macrophage polarization to the M1-like phenotype. Additionally, mouse atrial fibroblasts were incubated with the culture medium from RAW264.7 macrophages treated as described above. IL-12 overexpression rescued the NRON overexpression-inhibited protein levels of fibrosis markers Collagen I/III in mouse atrial fibroblasts. Collectively, our data indicate that lncRNA NRON alleviates atrial fibrosis through suppression of M1 macrophages activated by atrial myocytes.

12.
Cell Death Dis ; 10(12): 892, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31767832

RESUMO

Type 1 diabetes (T1D) is characterized by the selective autoimmune destruction of the islet ß cells, and macrophages play a significant role in this process. Small ubiquitin-like modification (SUMOylation) is an important posttranslational modification involved in T1D pathogenesis, but its function in macrophages remains unexplored. We presently developed and used macrophage-specific ubiquitin-conjugating enzyme E2 (Ubc9) knockout (LyzM-Cre-Ubc9fl/fl, KO) mice to address the impact of SUMOylation on macrophage function in a T1D model. We observed that blocking Ubc9 in macrophages exacerbated multiple-low dose streptozotocin (MLD-STZ)-induced diabetes. Specifically, after STZ treatment, blood glucose levels were consistently elevated in the KO mice. The KO mice exhibited a higher diabetes incidence than WT controls (85% vs. 55%, P < 0.01) along with a higher insulitis severity. The loss of Ubc9 impaired macrophage energy metabolism and attenuated macrophage M2 program, thereby enhancing T cell activation. Pancreas-resident macrophages, rather than migrant macrophages, played a predominant role in MLD-STZ-induced diabetes. Mechanistically, Ubc9-mediated SUMOylation of interferon regulator factor 4 (IRF4) enhanced its nuclear localization and stability, thereby transcribing IL-4 and arginase 1 (Arg1) to promote the macrophage M2 program. Ubc9-mediated SUMOylation modulates T1D risk at least in part by regulating macrophage function. Modulation of disturbed SUMOylation process in macrophages, either through cell adoptive transfer or targeted drug-delivery, could help to establish a tolerant pancreatic microenvironment and promote inflammation resolution in early insulitis stage, thus hindering T1D progression.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31778296

RESUMO

Respiratory chain complexes convert energy by coupling electron flow to transmembrane proton translocation. Owing to a lack of atomic structures of cytochrome bc1 complex (Complex III) from thermophilic bacteria, little is known about the adaptations of this macromolecular machine to hyperthermophilic environments. In this study, we purified the cytochrome bc1 complex of Aquifex aeolicus, one of the most extreme thermophilic bacteria known, and determined its structure with and without an inhibitor at 3.3 Šresolution. Several residues unique for thermophilic bacteria were detected that provide additional stabilization for the structure. An extra transmembrane helix at the N-terminus of cyt. c1 was found to greatly enhance the interaction between cyt. b and cyt. c1 , and to bind a phospholipid molecule to stabilize the complex in the membrane. These results provide the structural basis for the hyperstability of the cytochrome bc1 complex in an extreme thermal environment.

14.
J Cell Mol Med ; 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31749326

RESUMO

Cardiomyocyte apoptosis is an important process occurred during cardiac ischaemia-reperfusion injury. Long non-coding RNAs (lncRNA) participate in the regulation of various cardiac diseases including ischaemic reperfusion (I/R) injury. In this study, we explored the potential role of lncRNA ACART (anti-cardiomyocyte apoptosis-related transcript) in cardiomyocyte injury and the underlying mechanism for the first time. We found that ACART was significantly down-regulated in cardiac tissue of mice subjected to I/R injury or cultured cardiomyocytes treated with hydrogen peroxide (H2 O2 ). Knockdown of ACART led to significant cardiomyocyte injury as indicated by reduced cell viability and increased apoptosis. In contrast, overexpression of ACART enhanced cell viability and reduced apoptosis of cardiomyocytes treated with H2 O2 . Meanwhile, ACART increased the expression of the B cell lymphoma 2 (Bcl-2) and suppressed the expression of Bcl-2-associated X (Bax) and cytochrome-C (Cyt-C). In addition, PPAR-γ was up-regulated by ACART and inhibition of PPAR-γ abolished the regulatory effects of ACART on cell apoptosis and the expression of Bcl-2, Bax and Cyt-C under H2 O2 treatment. However, the activation of PPAR-γ reversed the effects of ACART inhibition. The results demonstrate that ACART protects cardiomyocyte injury through modulating the expression of Bcl-2, Bax and Cyt-C, which is mediated by PPAR-γ activation. These findings provide a new understanding of the role of lncRNA ACART in regulation of cardiac I/R injury.

15.
Artigo em Inglês | MEDLINE | ID: mdl-31755119

RESUMO

OBJECTIVES: This study focused on perceived threat of Alzheimer's disease and related dementias (ADRD) in Chinese older adults and investigated its associations with their perceived stigma and knowledge of ADRD. METHODS: We examined Chinese older adults' perceived threat of ADRD and its associations with perceived stigma, knowledge of ADRD, family variables and health variables. Data for this cross-sectional study were collected by student interviewers in 2016. The participants (N = 754) were recruited from two urban communities in mainland China and their ages ranged from 60 to 89 (M = 69.54, SD = 7.35). RESULTS: Hierarchical regression analyses indicated that those who are younger, have more depressive symptoms and lower levels of family cohesion are more likely to worry about ADRD. More ADRD knowledge and higher levels of perceived stigma are significantly associated with perceived threat of ADRD. Community site moderated the relationship between stigma and perceived threat of ADRD. CONCLUSIONS: Intervention or service programs need to promote ADRD knowledge and awareness in a culturally sensitive way as well as address stigma and fear toward ADRD in the older population. Future studies are needed to incorporate more cultural and environmental factors to fully understand Chinese older adults' attitudes toward and literacy of ADRD.

16.
Int J Pharm ; : 118806, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31678519

RESUMO

Breast cancer is one of the most frequent malignancies in the female population. Recently, the development of medical products has been advanced for this disease; however, patients still suffer from the failure of current treatments and new therapeutic strategies are urgently required. In this study, due to the overexpression of the estrogen receptor (ER) in breast cancer and the ability of ER to specifically bind to its ligand estrone (ES), an ES-targeted PEGylated epirubicin (EPI) and paclitaxel (PTX) co-loaded liposomal nanoparticle (NP) (termed as ES-SSL-EPI/PTX) was developed. Physicochemical studies demonstrated that the ES-SSL-EPI/PTX had a nanoscaled particle size (~120 nm) and a neutral zeta potential (~-5 mV) and presented favorable stability in physiological media. In vitro, the ES-SSL-EPI/PTX showed a significantly higher cellular uptake in human breast cancer MCF-7 cells mainly via the receptor-ligand mediated pathway resulting in effective cytotoxic activity. In vivo targeting study, the accumulation of targeted liposomes in tumor was significantly improved. The systemic circulation time and biodistribution in main organs of EPI and PTX delivered by ES-SSL-Liposomes were increased. Consequently, the ES-SSL-EPI/PTX significantly suppressed tumor growth in the MCF-7-derived tumor-bearing mouse model without inducing toxicity. These results suggested that the ES-SSL-EPI/PTX was a promising formulation for co-delivery of chemotherapeutics in the treatment of breast cancer.

17.
ACS Omega ; 4(14): 16045-16051, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31592175

RESUMO

A ligand-promoted iridium-catalyzed transfer hydrogenation of terminal alkynes with ethanol and its application has been developed. Highly chemical selectivity control is achieved based on ligand regulation. 1,2-Bis(diphenylphosphino)ethane was found to be critical for the transfer hydrogenation of alkynes. The general applicability of this procedure is highlighted by the synthesis of 30 terminal alkenes with a good yield. In addition, we conducted drug effect studies of phenelzine using zebrafish as the vertebrate model. Phenelzine shows a significant effect on promoting vascular proliferation and inhibiting nerve growth. The results of these studies have an important reference value for promoting drug research in cerebrovascular diseases, epilepsy, mania, and psychosis.

18.
Sci China Life Sci ; 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31625022

RESUMO

Three-dimensional electron microscopy (3D-EM) has attracted considerable attention because of its ability to provide detailed information with respect to developmental analysis. However, large-scale high-resolution 3D reconstruction of biological samples remains challenging. Herein, we present a 3D view of a Picea wilsonii Mast. pollen grain with 100 nm axial and 38.57 nm lateral resolution using AutoCUTS-SEM (automatic collector of ultrathin sections-scanning electron microscopy). We established a library of 3,127 100 nm thick serial sections of pollen grains for preservation and observation, demonstrating that the protocol can be used to analyze large-volume samples. After obtaining the SEM images, we reconstructed an entire pollen grain comprising 734 serial sections. The images produced by 3D reconstruction clearly revealed the main components of the P. wilsonii pollen grain, i.e., two sacci and pollen corpus, tube cell, generative cell, and two degenerated prothallial cells, and their internal organization. In addition, we performed a quantitative analysis of the different pollen grain cells, including sacci, and found that there were 202 connections within a saccus SEM image. Thus, for the first time, this study provided a global 3D view of the entire pollen grain, which will be useful for analyzing pollen development and growth.

19.
Plant Cell ; 31(12): 2855-2867, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31628168

RESUMO

Actins are among the most abundant and conserved proteins in eukaryotic cells, where they form filamentous structures that perform vital roles in key cellular processes. Although large amounts of data on the biochemical activities, dynamic behaviors, and important cellular functions of plant actin filaments have accumulated, their structural basis remains elusive. Here, we report a 3.9 Å structure of the plant actin filament from Zea mays pollen (ZMPA) using cryo-electron microscopy. The structure shows a right-handed, double-stranded (two parallel strands) and staggered architecture that is stabilized by intra- and interstrand interactions. While the overall structure resembles that of other actin filaments, its DNase I binding loop bends farther outward, adopting an open conformation similar to that of the jasplakinolide- or beryllium fluoride (BeFx)-stabilized rabbit skeletal muscle actin (RSMA) filament. Single-molecule magnetic tweezers analysis revealed that the ZMPA filament can resist a greater stretching force than the RSMA filament. Overall, these data provide evidence that plant actin filaments have greater stability than animal actin filaments, which might be important to their role as tracks for long-distance vesicle and organelle transportation.plantcell;31/12/2855/FX1F1fx1.

20.
Am J Respir Cell Mol Biol ; 61(6): 765-775, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31596601

RESUMO

S-nitrosothiols (SNOs) are endogenous signaling molecules that have numerous beneficial effects on the airway via cyclic guanosine monophosphate-dependent and -independent processes. Healthy human airways contain SNOs, but SNO levels are lower in the airways of patients with cystic fibrosis (CF). In this study, we examined the interaction between SNOs and the molecular cochaperone C-terminus Hsc70 interacting protein (CHIP), which is an E3 ubiquitin ligase that targets improperly folded CF transmembrane conductance regulator (CFTR) for subsequent degradation. Both CFBE41o- cells expressing either wild-type or F508del-CFTR and primary human bronchial epithelial cells express CHIP. Confocal microscopy and IP studies showed the cellular colocalization of CFTR and CHIP, and showed that S-nitrosoglutathione inhibits the CHIP-CFTR interaction. SNOs significantly reduced both the expression and activity of CHIP, leading to higher levels of both the mature and immature forms of F508del-CFTR. In fact, SNO inhibition of the function and expression of CHIP not only improved the maturation of CFTR but also increased CFTR's stability at the cell membrane. S-nitrosoglutathione-treated cells also had more S-nitrosylated CHIP and less ubiquitinated CFTR than cells that were not treated, suggesting that the S-nitrosylation of CHIP prevents the ubiquitination of CFTR by inhibiting CHIP's E3 ubiquitin ligase function. Furthermore, the exogenous SNOs S-nitrosoglutathione diethyl ester and S-nitro-N-acetylcysteine increased the expression of CFTR at the cell surface. After CHIP knockdown with siRNA duplexes specific for CHIP, F508del-CFTR expression increased at the cell surface. We conclude that SNOs effectively reduce CHIP-mediated degradation of CFTR, resulting in increased F508del-CFTR expression on airway epithelial cell surfaces. Together, these findings indicate that S-nitrosylation of CHIP is a novel mechanism of CFTR correction, and we anticipate that these insights will allow different SNOs to be optimized as agents for CF therapy.

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