Cold atom microwave clock based on intracavity cooling in China space station.

Atomic clocks with higher frequency stability and accuracy than traditional space-borne atomic clocks are the cornerstone of long-term autonomous operation of space-time-frequency systems. We proposed a space cold atoms clock based on an intracavity cooling scheme, which captures cold atoms at the center of a microwave cavity and then executes in situ interactions between the cold atoms and microwaves. As a result of the microgravity environment in space, the cold atoms can interact with the microwaves for a longer time, which aids in realizing a high-precision atomic clock in space. This paper presents the overall design, operational characteristics, and reliability test results of the space atomic clock based on the intracavity cooling scheme designed for the operation onboard the China space station. In addition, the engineering prototype performance of the space cold atoms microwave clock is also presented. The ground test results for the clock show a fractional frequency stability of 1.1 × 10-12 τ-1/2 reaching 2.5 × 10-15 at 200,000 s, providing solid technical and data support for its future operation in orbit.

Controlling smoking: A smoking epidemic model with different smoking degrees in deterministic and stochastic environments.

Engaging in smoking not only leads to substantial health risks but also imposes considerable financial burdens. To deepen our understanding of the mechanisms behind smoking transmission and to address the tobacco epidemic, we examined a five-dimensional smoking epidemic model that accounts for different degrees of smoking under both deterministic and stochastic conditions. In the deterministic case, we determine the basic reproduction number, analyze the stability of equilibria with and without smoking, and investigate the existence of saddle-node bifurcation. Our analysis reveals that the basic reproduction number cannot completely determine the existence of smoking, and the model possesses bistability, indicating its dynamic is susceptible to interference from environmental noises. In the stochastic case, we establish sufficient conditions for the ergodic stationary distribution and the elimination of smokers by constructing appropriate Lyapunov functions. Numerical simulations suggest that the effects of inevitable random fluctuations in the natural environment on controlling the smoking epidemic may be beneficial, harmful, or negligible, which are closely related to the noise intensities, initial smoking population sizes, and the effective exposure rate of smoking transmission (ß). Given the uncontrollable nature of environmental random effects, effective smoking control strategies can be achieved by: (1) accurate monitoring of initial smoking population sizes, and (2) implementing effective measures to reduce ß. Therefore, it is both effective and feasible to implement a complete set of strong MPOWER measures to control smoking prevalence.

A COP1-GATA2 axis suppresses AR signaling and prostate cancer.

Androgen receptor (AR) signaling is crucial for driving prostate cancer (PCa), the most diagnosed and the second leading cause of death in male patients with cancer in the United States. Androgen deprivation therapy is initially effective in most instances of AR-positive advanced or metastatic PCa. However, patients inevitably develop lethal castration-resistant PCa (CRPC), which is also resistant to the next-generation AR signaling inhibitors. Most CRPCs maintain AR expression, and blocking AR signaling remains a main therapeutic approach. GATA2 is a pioneer transcription factor emerging as a key therapeutic target for PCa because it promotes AR expression and activation. While directly inhibiting GATA2 transcriptional activity remains challenging, enhancing GATA2 degradation is a plausible therapeutic strategy. How GATA2 protein stability is regulated in PCa remains unknown. Here, we show that constitutive photomorphogenesis protein 1 (COP1), an E3 ubiquitin ligase, drives GATA2 ubiquitination at K419/K424 for degradation. GATA2 lacks a conserved [D/E](x)xxVP[D/E] degron but uses alternate BR1/BR2 motifs to bind COP1. By promoting GATA2 degradation, COP1 inhibits AR expression and activation and represses PCa cell and xenograft growth and castration resistance. Accordingly, GATA2 overexpression or COP1 mutations that disrupt COP1-GATA2 binding block COP1 tumor-suppressing activities. We conclude that GATA2 is a major COP1 substrate in PCa and that COP1 promotion of GATA2 degradation is a direct mechanism for regulating AR expression and activation, PCa growth, and castration resistance.

Prevalence and risk factors of enteral nutrition intolerance in intensive care unit patients: a retrospective study.

BACKGROUND: Feeding intolerance (FI) among intensive care unit (ICU) patients undergoing early continuous enteral nutrition (EN) is related to poor outcomes. This study aimed to explore the prevalence and risk factors of FI in ICU patients. METHODS: We retrospectively enrolled 1057 patients who received early continuous EN via a nasogastric tube between January 2014 and August 2019. The prevalence of FI during the first 7 days of ICU stay was calculated, and the risk factors were investigated using multivariate logistic regression analysis. RESULTS: The prevalence of FI during the first 7 days of ICU stay was 10.95%. FI occurred in 159 of 1057 (15.04%) patients on ICU day 2, 114 of 977 (11.67%) patients on ICU day 3, and 86 of 715 (12.03%) patients on ICU day 7. Mechanical ventilation (MV) (odds ratio [OR]: 1.928, 95% confidence interval [CI]: 1.064-3.493, P  = 0.03) was an independent risk factor for FI defined by a gastric residual volume (GRV) of 200 mL and/or vomiting, and acute renal failure (OR: 3.445, 95% CI: 1.115-10.707, P  = 0.032) was an independent risk factor of FI defined by a GRV of 500 mL and/or vomiting. Continuous renal replacement therapy (CRRT) was an independent predictor regardless of the FI defined by a GRV of 200 mL (OR: 2.064, 95% CI: 1.233-3.456, P  = 0.006) or 500 mL (OR: 6.199, 95% CI: 2.108-18.228, P  = 0.001) in the ICU patients. CONCLUSIONS: FI occurs frequently in early ICU days, especially in patients receiving MV and CRRT. However, further investigation of a consensus definition of FI and risk factors is still warranted in future studies.

MAPK4 promotes triple negative breast cancer growth and reduces tumor sensitivity to PI3K blockade.

About 15-20% of breast cancer (BCa) is triple-negative BCa (TNBC), a devastating disease with limited therapeutic options. Aberrations in the PI3K/PTEN signaling pathway are common in TNBC. However, the therapeutic impact of PI3K inhibitors in TNBC has been limited and the mechanism(s) underlying this lack of efficacy remain elusive. Here, we demonstrate that a large subset of TNBC expresses significant levels of MAPK4, and this expression is critical for driving AKT activation independent of PI3K and promoting TNBC cell and xenograft growth. The ability of MAPK4 to bypass PI3K for AKT activation potentially provides a direct mechanism regulating tumor sensitivity to PI3K inhibition. Accordingly, repressing MAPK4 greatly sensitizes TNBC cells and xenografts to PI3K blockade. Altogether, we conclude that high MAPK4 expression defines a large subset or subtype of TNBC responsive to MAPK4 blockage. Targeting MAPK4 in this subset/subtype of TNBC both represses growth and sensitizes tumors to PI3K blockade.

Quality of life in ambulatory pulmonary arterial hypertension in connective tissue diseases and its relationship with risk stratification.

The Pulmonary Arterial Hypertension Symptoms and Impact Questionnaire (PAH-SYMPACT) is a PAH-specific patient-reported outcome scale assessing patients' quality of life from four aspects: cardiopulmonary symptoms, cardiovascular symptoms, physical impacts and cognitive/emotional impacts. This study aimed to validate the Chinese version of PAH-SYMPACT and explore its relationship with risk stratification in patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH). In addition, 75 patients with CTD-PAH confirmed by right heart catheterization were invited to complete questionnaires including PAH-SYMPACT, the 36-item Medical Outcomes Study Short Form Survey (SF-36) and EuroQol five dimensions questionnaire (EQ-5D). The demographic, clinical, laboratory and treatment data were collected. The endpoint was treatment goal achievement status in 6-12 months after completing the questionnaires, defined as an integrated outcome. Participants' mean age was 36.4 ± 11.9 years and the mean pulmonary arterial pressure was 38.9 ± 13.67 mmHg. The reliability of the PAH-SYMPACT domains ranged from 0.83 to 0.88. Results of factor analysis basically conformed the original PAH-SYMPACT. The treatment goal achievement (TGA) status in 6-12 months was significantly associated with physical impacts scores (odds ratio: 0.180, 95% confidence interval: 0.036-0.908, P=0.038). The Chinese version of PAH-SYMPACT is a reliable measurement to evaluate quality of life in CTD-PAH patients and is also a potential predictor of patient's condition change in routine clinical practice.

α7 Nicotinic Acetylcholine Receptor Agonist PNU-282987 Ameliorates Cognitive Impairment Induced by Chronic Intermittent Hypoxia.

PURPOSE: Cognitive impairment is an important complication of obstructive sleep apnea (OSA). Chronic intermittent hypoxia (CIH), the main pathophysiological characteristics of OSA, is closely related to cognitive dysfunction and may be mediated by alpha-7 nicotinic acetylcholine receptors (α7nAChR). This study investigated the effects and clarified the mechanisms of α7nAChR on the cognitive function of mice with CIH. METHODS: Thirty CD-1 mice were randomly divided into room air (RA), CIH-2 weeks (CIH2W), and CIH-4 weeks (CIH4W) groups. Cognitive function was evaluated by novel object recognition (NOR) and Morris water maze (MWM) tests after exposure. Then, 104 CD-1 mice were exposed to CIH for 4 weeks and randomly divided into four groups: CIH4W (control), with dimethyl sulfoxide (DMSO) (sham), with α7nAChR-specific agonist PNU-282987 (PNU), and with α7nAChR-specific inhibitor methyllycaconitine and PNU-282987 (MLA+PNU). In addition to the evaluation of cognitive function, apoptotic bodies in the hippocampus were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, changes in p-CREB and BDNF were detected by immunohistochemistry, while those of ERK1/2, CREB, PGC-1α, FNDC5, and BDNF were detected by Western blotting in the hippocampal tissues of the mice. RESULTS: Compared to the CIH2W and RA groups, the CIH4W group showed cognitive dysfunction in the NOR and MWM tests. The changes in cognitive dysfunction were alleviated by PNU-282987; furthermore, MLA pretreatment offset the effect. In hippocampal tissues, TUNEL assays showed decreased apoptotic cells, immunohistochemical staining showed increased expressions of p-CREB and BDNF. The expression levels of p-ERK1/2/t-ERK1/2, p-CREB/t-CREB, PGC-1α, FNDC5, and BDNF were increased after PNU-282987 injection. CONCLUSION: Four weeks of CIH caused cognitive dysfunction in mice. Activating α7nAChR might ameliorate this dysfunction by upregulating the ERK1/2/CREB signaling pathway; enhancing PGC-1α, FNDC5, and BDNF expression levels; and reducing cell apoptosis in the hippocampal tissue of mice.

MAPK4 promotes prostate cancer by concerted activation of androgen receptor and AKT.

Prostate cancer (PCa) is the second leading cause of cancer death in American men. Androgen receptor (AR) signaling is essential for PCa cell growth/survival and remains a key therapeutic target for lethal castration-resistant PCa (CRPC). GATA2 is a pioneer transcription factor crucial for inducing AR expression/activation. We recently reported that MAPK4, an atypical MAPK, promotes tumor progression via noncanonical activation of AKT. Here, we demonstrated that MAPK4 activated AR by enhancing GATA2 transcriptional expression and stabilizing GATA2 protein through repression of GATA2 ubiquitination/degradation. MAPK4 expression correlated with AR activation in human CRPC. Concerted activation of both GATA2/AR and AKT by MAPK4 promoted PCa cell proliferation, anchorage-independent growth, xenograft growth, and castration resistance. Conversely, knockdown of MAPK4 decreased activation of both AR and AKT and inhibited PCa cell and xenograft growth, including castration-resistant growth. Both GATA2/AR and AKT activation were necessary for MAPK4 tumor-promoting activity. Interestingly, combined overexpression of GATA2 plus a constitutively activated AKT was sufficient to drive PCa growth and castration resistance, shedding light on an alternative, MAPK4-independent tumor-promoting pathway in human PCa. We concluded that MAPK4 promotes PCa growth and castration resistance by cooperating parallel pathways of activating GATA2/AR and AKT and that MAPK4 is a novel therapeutic target in PCa, especially CRPC.

How Does Chronic Intermittent Hypoxia Influence Upper Airway Stability in Rats?

BACKGROUND: Obstructive sleep apnea (OSA) is characterized by repetitive episodes of upper airway collapse during sleep. The contraction of upper airway dilator muscles plays a crucial role in maintaining UA patency. Chronic intermittent hypoxia (CIH) is the most important pathophysiological process of OSA. Exposure to CIH induced not only the damage of dilator muscles but also the plasticity of the muscles. This study aimed to dynamically assess the influence of CIH on the upper airway. METHODS: The experiments were performed on 44 rats. They were randomly divided into a normoxia (NO) group (n=22) and CIH group (n=22). In each group (n=6, respectively), EMG, transcranial magnetic stimulation (TMS) response, and critical pressure (Pcrit) value were recorded on day 0 (the day before exposure), and the 7th, 14th, 21st, and 28th day of air/CIH exposure. For each group, 16 rats were used for transmission electron microscopy observations on day 0, and the 7th, 14th and 28th day of air/CIH exposure (n=4 for every time point). RESULTS: Compared to the NO group at the same point, the CIH group showed a damaged ultrastructure of genioglossus, increased activity of genioglossus corticomotor area, and increased Pcrit of the upper airway from the 7th to the 28th day of CIH. Increased EMG activity occurred at the 14th day of CIH and lasted for 2 weeks. CONCLUSION: The elevated genioglossus corticomotor excitability in response to the CIH could not counterbalance the damage effect of CIH on upper airway dilator muscles, which ultimately increased the collapsibility of the upper airway.

Hyperglycemia suppresses the regulatory effect of hypoxia-inducible factor-1α in pulmonary Aspergillus fumigatus infection.

Aspergillus fumigatus is one of the most common fungal infections involved in the pulmonary diseases. Hypoxia-inducible factor-1α (HIF-1α) is important for antifungal immunity. Diabetes is a risk factor of pulmonary A. fumigatus infection and could affect the expression of HIF-1α. The aim of this investigation was to evaluate the role of HIF-1α in pulmonary A. fumigatus infection in diabetes. In murine model, we found diabetic mice had aggravated pulmonary A. fumigatus infection and declined expression of HIF-1α following pulmonary A. fumigatus infection. And these changes could be corrected by dimethyloxalylglycine (DMOG), the agonist of HIF-1α. In cell experiment, after A. fumigatus stimulation, hyperglycemic state was with a decreased HIF-1α expression and increased NLRP3/IL-1ß signal pathway. The percentages of Th1 and Treg cells decreased, while percentages of Th2 and Th17 increased in hyperglycemic group. DMOG suppressed A. fumigatus-stimulated NLRP3 and IL-1ß expressions in hyperglycemic group and corrected Th and Treg cells differentiation. These regulatory effects of DMOG could be dampened by activating of NLRP3. These data indicated that hyperglycemia suppressed the regulatory effect of HIF-1α in pulmonary A. fumigatus infection, which can affect Th and Treg cells differentiation by regulating the NLRP3/IL-1ß signal pathway.

AHNAK Nucleoprotein 2 Performs a Promoting Role in the Proliferation and Migration of Uveal Melanoma Cells.

AHNAK nucleoprotein 2 (AHNAK2) is supposed to participate in calcium signaling and cytoarchitecture by directly interacting with some proteins. Recently, it was identified as a novel candidate oncogene in human tumors. The author's present study aimed to investigate the expression and biological function of AHNAK2 in uveal melanoma (UM). Based on microarray data of 63 UM patients that were downloaded from Gene Expression Omnibus database, the authors found that AHNAK2 expression is higher in UM primary tumor tissues from patients who developed metastases after enucleation than that in UM primary tumor tissues from patients without metastasis after enucleation. On the basis of the data obtained from The Cancer Genome Atlas database, they found that high AHNAK2 expression is closely associated with shorter overall survival time in UM patients. From quantitative reverse transcription polymerase chain reaction analyses, they revealed that the mRNA expression level of AHNAK2 was significantly upregulated in M17 and SP6.5 cell lines compared with that in D78. Functionally, knockdown of AHNAK2 using small interfering RNA in M17 and SP6.5 cells dramatically suppressed cell proliferation, migratory and invasive abilities, as well as inhibited the activation of phosphatidylinositol 3-kinase (PI3K) signaling pathway. Taken together, their results illustrated that AHNAK2 was upregulated in UM and plays a promoting role in the proliferation and migration of UM cells possibly via regulating PI3K signaling pathway.

Chlorhexidine gluconate transparent dressing does not decrease central line-associated bloodstream infection in critically ill patients: A randomized controlled trial.

BACKGROUND: Central line-associated blood stream infections are accompanied by increased mortality and health care costs. The application of different types of dressings in infection control has not been fully investigated to date. AIM: To assess the effects of two different dressing types on central line-associated bloodstream infections. METHODS: A randomized, nonblinded, controlled trial was conducted. Central lines were randomly allocated to intervention (chlorhexidine gluconate transparent dressing, n = 259) and control groups (standard dressing, n = 215). The central line-associated bloodstream infection rate was assessed. RESULTS: A statistically nonsignificant difference was noted in the overall central line-associated bloodstream infection rates between the two groups. The frequency of dressing changes in the patients with the chlorhexidine gluconate transparent dressing was significantly lower than that in the patients with a standard dressing. The predominant type of infectious microorganisms isolated from the central line-associated bloodstream infection episodes was Gram-negative bacteria (57.2%). Gram-positive bacteria and fungi were noted at lower percentages (28.5% and 14.3%, respectively). CONCLUSION: The use of a chlorhexidine gluconate transparent dressing does not decrease the central line-associated bloodstream infection rate, although it decreases the frequency of dressing changes so may save nursing time.

An integrated laser system for the cold atom clock.

We demonstrate an integrated laser system for the mobile integrating sphere cold atom clock. Three distributed Bragg reflector diode lasers (780 nm) with custom drive circuits are used for the cooling, repumping, pumping, and probe lights. Automatic frequency-locking and relocking of the laser are presented. All of the optical elements are integrated on two sides of an aluminum base plate. The mechanical structure is simulated and optimized to minimize the deformation of the base plate. We optimize, measure, and discuss the frequency and intensity noises of the laser system. The techniques and designs used in this laser system can also be used in other mobile platforms for quantum sensing experiments.

MAPK4 overexpression promotes tumor progression via noncanonical activation of AKT/mTOR signaling.

MAPK4 is an atypical MAPK. Currently, little is known about its physiological function and involvement in diseases, including cancer. A comprehensive analysis of 8887 gene expression profiles in The Cancer Genome Atlas (TCGA) revealed that MAPK4 overexpression correlates with decreased overall survival, with particularly marked survival effects in patients with lung adenocarcinoma, bladder cancer, low-grade glioma, and thyroid carcinoma. Interestingly, human tumor MAPK4 overexpression also correlated with phosphorylation of AKT, 4E-BP1, and p70S6K, independent of the loss of PTEN or mutation of PIK3CA. This led us to examine whether MAPK4 activates the key metabolic, prosurvival, and proliferative kinase AKT and mTORC1 signaling, independent of the canonical PI3K pathway. We found that MAPK4 activated AKT via a novel, concerted mechanism independent of PI3K. Mechanistically, MAPK4 directly bound and activated AKT by phosphorylation of the activation loop at threonine 308. It also activated mTORC2 to phosphorylate AKT at serine 473 for full activation. MAPK4 overexpression induced oncogenic outcomes, including transforming prostate epithelial cells into anchorage-independent growth, and MAPK4 knockdown inhibited cancer cell proliferation, anchorage-independent growth, and xenograft growth. We concluded that MAPK4 can promote cancer by activating the AKT/mTOR signaling pathway and that targeting MAPK4 may provide a novel therapeutic approach for cancer.

Retraction Note: Nuclear factor of activated T cells 5 maintained by Hotair suppression of miR-568 upregulates S100 calcium binding protein A4 to promote breast cancer metastasis.

The authors are retracting this article [1] after an investigation by the Ethics Committee of the Fourth Military Medical University (Xi'an, Shaanxi, China) of the following concerns that had been raised with respect to two of the figures.

A Versatile Tumor Gene Deletion System Reveals a Crucial Role for FGFR1 in Breast Cancer Metastasis.

RCAS avian viruses have been used to deliver oncogene expression and induce tumors in transgenic mice expressing the virus receptor TVA. Here we report the generation and characterization of a novel RCAS-Cre-IRES-PyMT (RCI-PyMT) virus designed to specifically knockout genes of interest in tumors generated in appropriate mutant mouse hosts. FGF receptor 1 (FGFR1) is a gene that is amplified in human breast cancer, but there have been no definitive studies on its function in mammary tumorigenesis, progression, and metastasis in vivo in spontaneous tumors in mice. We used the retroviral tumor knockout, or TuKO, strategy to delete fgfr1 in PyMT-induced mammary tumors in K19-tva/fgfr1loxP/loxP mice. The similarly injected control K19-tva mice developed mammary tumors exhibiting high metastasis to lung, making this an ideal model for breast cancer metastasis. The fgfr1 TuKO tumors showed significantly decreased primary tumor growth and, most importantly, greatly reduced metastasis to lung. In contrast to previous reports, FGFR1 action in this spontaneous mammary tumor model does not significantly induce epithelial-to-mesenchymal transition. Loss of FGFR1 does generate a gene signature that is reverse correlated with FGFR1 gene amplification and/or upregulation in human breast cancer. Our results suggest that FGFR1 signaling is a key pathway driving breast cancer lung metastasis and that targeting FGFR1 in breast cancer is an exciting approach to inhibit metastasis.

Nuclear factor of activated T cells 5 maintained by Hotair suppression of miR-568 upregulates S100 calcium binding protein A4 to promote breast cancer metastasis.

INTRODUCTION: The onset of distal metastasis, which underlies the high mortality of breast cancers, warrants substantial studies to depict its molecular basis. Nuclear factor of activated T cells 5 (NFAT5) is upregulated in various malignancies and is critically involved in migration and invasion of neoplastic cells. Nevertheless, the metastasis-related events potentiated by this transcriptional factor and the mechanism responsible for NFAT5 elevation in carcinoma cells remain to be fully elucidated. METHODS: The correlation of NFAT5 with breast cancer invasiveness was investigated in vitro and clinically. The genes transcriptionally activated by NFAT5 were probed and their roles in breast cancer progression were dissected. The upstream regulators of NFAT5 were studied with particular attempt to explore the involvement of non-coding RNAs, and the mechanism underlying the maintenance of NFAT5 expression was deciphered. RESULTS: In metastatic breast cancers, NFAT5 promotes epithelial-mesenchymal transition (EMT) and invasion of cells by switching on the expression of the calcium binding protein S100A4, and facilitates the angiogenesis of breast epithelial cells and thus the development of metastases by transcriptionally activating vascular endothelial growth factor C (VEGF-C). NFAT5 is directly targeted by miR-568, which is in turn suppressed by the long non-coding RNA, Hotair, via a documented in trans gene silencing pattern, that is recruitment of the polycomb complex (Polycomb Repressive Complex 2; PRC2) and LSD1, and consequently methylation of histone H3K27 and demethylation of H3K4 on the miR-568 loci. CONCLUSION: This study unravels a detailed role of NFAT5 in mediating metastatic signaling, and provides broad insights into the involvement of Hotair, in particular, by transcriptionally regulating the expression of microRNA(s), in the metastasis of breast cancers.

c-Myc-mediated epigenetic silencing of MicroRNA-101 contributes to dysregulation of multiple pathways in hepatocellular carcinoma.

UNLABELLED: The MYC oncogene is overexpressed in hepatocellular carcinoma (HCC) and has been associated with widespread microRNA (miRNA) repression; however, the underlying mechanisms are largely unknown. Here, we report that the c-Myc oncogenic transcription factor physically interacts with enhancer of zeste homolog 2 (EZH2), a core enzymatic unit of polycomb repressive complex 2 (PRC2). Furthermore, miR-101, an important tumor-suppressive miRNA in human hepatocarcinomas, is epigenetically repressed by PRC2 complex in a c-Myc-mediated manner. miR-101, in turn, inhibits the expression of two subunits of PRC2 (EZH2 and EED), thus creating a double-negative feedback loop that regulates the process of hepatocarcinogenesis. Restoration of miR-101 expression suppresses multiple malignant phenotypes of HCC cells by coordinate repression of a cohort of oncogenes, including STMN1, JUNB, and CXCR7, and further increases expression of endogenous miR-101 by inhibition of PRC2 activation. In addition, co-overexpression of c-Myc and EZH2 in HCC samples was closely associated with lower expression of miR-101 (P < 0.0001) and poorer prognosis of HCC patients (P < 0.01). CONCLUSIONS: c-Myc collaborates with EZH2-containing PRC2 complex in silencing tumor-suppressive miRNAs during hepatocarcinogenesis and provides promising therapeutic candidates for human HCC.

MiR-568 inhibits the activation and function of CD4⁺ T cells and Treg cells by targeting NFAT5.

CD4(+) T cells play critical roles in orchestrating adaptive immune responses. Their activation and proliferation are critical steps that occur before they execute their biological functions. Despite the important role of this process, the underlying molecular events are not fully understood. MicroRNAs (miRNAs) have been shown to play important roles in lymphocyte development and function. However, the miRNAs that regulate T-cell differentiation, activation and proliferation are still largely unknown. In our previous study, using a miRNA array, we found that several miRNAs (including miR-202, 33b, 181c, 568 and 576) are differentially expressed between resting and activated CD4(+) T cells. In this study, we focused on the function of miR-568 during CD4(+) T-cell activation. We showed that the expression level of miR-568 decreased during the activation of T cells, including Jurkat cells and human peripheral blood CD4(+) T cells. When Jurkat or human peripheral blood CD4(+) T cells were transfected with miR-568 mimics, cell activation was significantly inhibited, as shown by the inhibited expression of activation markers such as CD25, CD69 and CD154; decreased IL-2 production; and inhibited cell proliferation. Using software predictions and confirmatory experiments, we demonstrated that nuclear factor of activated T cells 5 (NFAT5) is a target of miR-568. Treg cells are an important CD4(+) T-cell subpopulation, so we also evaluated the function of miR-568 in Treg-cell activation and differentiation. We showed that the miR-568 level decreased, while the NFAT5 protein level increased during CD4(+)CD25(+) Treg-cell activation, and the transfection of miR-568 mimics inhibited the NFAT5 expression, inhibited the production of both TGF-ß and IL-10 and also inhibited the proliferation of Treg cells. Our further study showed that over-expression of miR-568 can inhibit Treg-cell differentiation and can inhibit the suppressive effect of these cells on effector cells. In addition, inhibition of NFAT5 by siRNA-mediated knockdown can inhibit the activation and differentiation of Treg cells. These findings reveal that miR-568 can inhibit the activation and function of both CD4(+) T cells and Treg cells by targeting NFAT5. Since miR-568 plays an important role in both CD4(+) T cells and Treg cells, these findings may provide leads for the development of novel treatments for human inflammatory and autoimmune diseases.

B7-H1 expression is associated with poor prognosis in colorectal carcinoma and regulates the proliferation and invasion of HCT116 colorectal cancer cells.

BACKGROUND AND OBJECTIVE: The investigation concerning the B7-H1 expression in colorectal cancer cells is at an early stage. It is unclear whether B7-H1 expression may have diagnostic or prognostic value in colorectal carcinoma. Additionally, how B7-H1 is associated with the clinical features of colorectal carcinoma is not known. In order to investigate the relationship between B7-H1 and colorectal cancer, we analyzed B7-H1 expression and its effect in clinical specimens and HCT116 cells. METHODS: Paraffin-embedded specimens from 143 eligible patients were used to investigate the expression of CD274 by immunohistochemistry. We also examined whether B7-H1 itself may be related to cell proliferation, apoptosis, migration and invasion in colon cancer HCT116 cells. RESULTS: Our results show that B7-H1 was highly expressed in colorectal carcinoma and was significantly associated with cell differentiation status and TNM (Tumor Node Metastasis) stage. Patients with positive B7-H1 expression showed a trend of shorter survival time. Using multivariate analysis, we demonstrate that positive B7-H1 expression is an independent predictor of colorectal carcinoma prognosis. Our results indicate that B7-H1 silencing with siRNA inhibits cell proliferation, migration and invasion. Furthermore, cell apoptosis was also increased by B7-H1 inhibition. CONCLUSIONS: Positive B7-H1 expression is an independent predictor for colorectal carcinoma prognosis. Moreover, knockdown of B7-H1 can inhibit cell proliferation, migration and invasion.